NWOBI, CHIGOZIE IVOR - University of Nigeria, Nsukka CHIGOZIE IVOR.pdf · Nwobi, Chigozie Ivor PG/M.Sc/03/37246 A D is er ta on Subm d h Department of Medical Radiography and Radiological

DEPARTMENT OF MEDICAL RADIOGRAPHY AND RADIOLOGICAL

A THESIS SUBMITTED T

RADIOLOGICAL SCIENCES, FACULTY OF HEALTH

UNIVERSITY OF NIGERIA ENUGU CAMPUS

1

NWOBI, CHIGOZIE IVORPG/M.Sc/03/37246

SONOGRAPHIC ASSESSMENT OF FOETAL THORACIC CIRCUMFERENCE AS A PREDICTOR OF GESTATIONAL

AGE IN MAIDUGURI, NORTH EAST NIGERIA

DEPARTMENT OF MEDICAL RADIOGRAPHY AND RADIOLOGICAL SCIENCES, UNIVERSITY OF NIGERIA, NSUKKA

A THESIS SUBMITTED TO THE DEPARTMENT OF MEDICAL RADIOGRAPHY AND

RADIOLOGICAL SCIENCES, FACULTY OF HEALTH SCIENCES AND TECHNOLOGY


Webmaster

Digitally Signed by Webmaster’s NameDN : CN = Webmaster’s name O= University of Nigeria, NsukkaOU = Innovation Centre

FEBRUARY 2012

CHIGOZIE IVOR



DEPARTMENT OF MEDICAL RADIOGRAPHY AND RADIOLOGICAL , UNIVERSITY OF NIGERIA, NSUKKA

O THE DEPARTMENT OF MEDICAL RADIOGRAPHY AND

SCIENCES AND TECHNOLOGY,

Webmaster’s Name DN : CN = Webmaster’s name O= University of Nigeria, Nsukka

2



BY

NWOBI, CHIGOZIE IVOR PG/M.Sc/03/37246

DEPARTMENT OF MEDICAL RADIOGRAPHY AND RADIOLOGICAL SCIENCES

FACULTY OF HEALTH SCIENCES AND TECHNOLOGY COLLEGE MEDICINE


FEBRUARY, 2012.

3

TITLE PAGE



BY

Nwobi, Chigozie Ivor PG/M.Sc/03/37246

A Dissertation Submitted to the Department of Medical Radiography and Radiological Sciences, Faculty of Health Sciences and Technology, College Medicine, University of Nigeria, Enugu Campus

IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF MASTER OF SCIENCE (M.Sc) DEGREE IN

MEDICAL IMAGING

SPECIALTY: MEDICAL IMAGING

SUPERVISOR: PROF. K. K. AGWU

FEBRUARY, 2012.

4

APPROVAL PAGE

Name: NWOBI, CHIGOZIE IVOR

Reg. No. PG/M.Sc/03/37246

Degree: M.Sc

Specialty: Medical Imaging (Medical Ultrasound)

Title of Dissertation: Sonographic Assessment of Foetal Thoracic

Circumference as a Predictor of Gestational

Age in Maidurguri, North East, Nigeria

Examination Committee

…………………. ………………………. Dr. C. U. Eze Prof. K. K. Agwu Head of Department Supervisor

……….…………….. Dr. T. T. Marchie External Examiner

Date of Approval …………..

5

DEDICATION

To my parents; Chief J. U. Nwobi and Late Augustina Nwobi of blessed

memory. My Aunty, Miss Margaret Nweze, for their love and support.

6

ACKNOWLEDGEMENT

I am grateful to Almighty God for his love and guidance for granting me

grace to successfully complete this study. The success of this study was

made possible by many people who were involved in supervision,

support, provision of material resources, advice and encouragement. My

gratitude goes to my supervisor, Prof. K. K. Agwu for his constructive

criticism, motivation and support. I appreciate Dr. Ahidjo Ahmed

(Former Head, Radiology Department, University of Maiduguri Teaching

Hospital UMTH, Consultant Radiologist) and Prof. Audu Bala (former

Deputy CMAC, UMTH and consultant Obstetrics and Gyaenacologist)

for their permission and provision of subjects for data collection and for

also sharing their experiences and expertise in the study. The staff of

radiology and O&G departments are appreciated for their collaboration

and provision of enabling environment for the study.

Special thanks to Prof. Tahir A., Chief Medical Director, University of

Maiduguri Teaching Hospital, for his encouragement and support to

seeing the completion of this work.

Dr. Eze C.U., Head of department of Medical Radiography and

Radiological Sciences, Dr. Okeji Mark, Dr. Ogbu S.O.I, Mr. Ochie Kalu,

Mr. Nwadike and Mrs. Angel Mary provided advice and contributions to

the dissertation, for which I am grateful.

7

I acknowledge Mrs. Idigo F.U. and Dr. Okaro, former heads of

department, for the guidance and assistance in making the work possible.

Finally, I want to acknowledge, My late elder brother,Simon Nwobi, my

brothers and sisters, colleagues, friends and relations for their moral

support and love during the period of the study.

8

ABSTRACT

The purpose of this research was to establish a nomogram of thoracic

circumference as a predictor of GA. The foetus of 907 singleton pregnant

woman referred to the Radiology Department of UMTH and obtained through

consecutive enlistment were scanned for the purpose of establishing a

nomogram of thoracic circumference (TC) as a predictor of gestation age. Only

apparently healthy subjects were enlisted and those between gestational age of

15 weeks-41 weeks were included. A cross sectional prospective research

design was adopted for this study using a convenient sampling technique.

Ethical approval was also obtained from the ethical committee of the hospital

and informed consent was obtained from each participant before data collection

commenced. The sonographic examinations were performed using a two-

dimensional, high resolution, real time ultrasound, ALOKA Prosound 3500

manufactured in Japan in 2005, and equipped with a 3.5MHz curvilinear,

transabdominal transducer. The TC was measured and in accordance with the

recommendations of American College of Radiology (ACR). Regression

analysis was applied to establish the relationship between TC and GA and the

coefficient by Pearson’s moment correlation. The BPD, HC, AC and FL were

also measured and the accuracy of TC in predicting GA compared with these

biometric parameters. Geometric mean was used to determine fetal growth rate.

Student t test (two tails) was used to determine if there was statistical

difference between TC of Caucasian and that of Nigerian population. The TC

values ranged from 9.159cm to 32.168cm for the 15-41 weeks of gestation. The

growth rate at the second trimester was 0.8169/week and third trimester

0.8217/week. The coefficient of the relationship between TC and GA was

0.974 and the regression analysis yielded the equation y = 4.65 + 1.13TC. The

accuracy of TC in predicting GA is 97.40% while those of BPD, HC, AC

and FL accuracy were 98.24%, 98.06%, 97.12%, and 98.62% respectively.

There was no statistically significant difference between TC and other

established biometric parameters in predicting GA. The accuracy of TC to

predict GA was highest at the second trimester.

9

TABLE OF CONTENTS

Title Page i

Approval Page ii

Dedication iii

Acknowledgement iv

Abstract vi

Table of Contents vii

List of Tables x

List of Figures xi

List of Appendices xiii

List of Abbreviations xiv

CHAPTER ONE: INTRODUCTION

1.1 Background of the Study 1

1.2 Statement of the Problems 4

1.3 Objectives of the Study 5

1.4 Significance of the Study 6

1.5 Scope of the Study 6

1.6 Limitations of the Study 7

1.7 Literature Review 7

1.8 Operational Definition of Terms 11

10

CHAPTER TWO: THEORETICAL BACKGROUND

2.1 Embryology of Foetal Chest Development 15

2.2 Anatomy 17

2.3 Hereditary Defect of Foetal Chest 18

2.4 Sonographic Assessment of Thoracic Circumference as

Prediction of Gestation Age 21

2.5 Sonographic Assessment of other Parameters to Determine

Gestation Age 24

2.6 Other Imaging Modalities used for Fetal Dating 32

2.7 Clinical Methods of Estimating Gestational Age 33

CHAPTER THREE: RESEARCH METHODS

3.1 Introduction 36

3.2 Research Design 36

3.3 Setting of Study 36

3.4 Study Population 37

3.5 Determination of Sample Size and Sampling Technique 38

36 Sources of Data 38

37 Ethical Consideration 39

3.8 Recruitment of Subject, Inclusion/Exclusion Criteria 39

3.9 Method of Data Collection 40

3.10 Dating Model 47

11

3.11 Method of Data Analysis 48

CHAPTER FOUR: PRESENTATION OF RESULTS AND

DISCUSSION

4.1 Introduction 49

4.2 Results 49

4.3 Inferential Analysis 56

4.4 Feta Thoracic Circumference Growth Rate 56

4.5 Prediction of GA from TC 56

4.6 Discussion 63

CHAPTER FIVE: SUMMARY AND CONCLUSIONS,

5.0 Summary of Major Findings 66

5.1 Conclusions 67

5.2 Recommendations Based on Finding 67

5.3 Study’s Contributions to Knowledge 68

5.4 Areas of Further Studies 68

References 69

Appendices 75

12

LIST OF TABLES

Table 1: Age Variability in Weeks 32

Table 2: Distribution of the participants according to tribe 50

Table 3: Mean values of TC matched against GA 53

Table 4: Comparism between 50th percentile TC in Nigerians

(derived nomogram) and the caucasians 55

Table 5: Predic5ted GA from equation 75th Percentile in Nigerians

GA = 4.65 + 1.13 TC 57

Table 6: Regression model for TC against BPD, FL, HC. 62

Table 7: Gestational age groups and their coefficient of determination 62

Table 8: Mean values of BPD, FL, HC and TC with GA 78

Table 9: Comparison of mean values of TC and HC against GA 79

13

LIST OF FIGURES

Fig 1: IUGR Pictural diagram 14

Fig 2: Foetal chest sonogram 17

Fig 3: Foetal ribs and spines sonogram 17

Fig 4: Four Chamber sonogram with colour Doppler 22

Fig 5: Four heart chamber view and chest circumference of foetus 22

Fig 6: Foetal skull with Biparietal diameter 25

Fig 7: Foetal Derived Head Circumference Sonogram 27

Fig 8: Correct Femur Length outline Sonogram 30

Fig. 9a: Incorrect the femur (f) length sonogram should not be measured

unless it is perpendicular to the transducer 30

Fig.9b: Incorrect bowed femur length sonogram 31

Fig 10:Sonographic appearance of derived thoracic circumference 41

Fig 11: Imaging of the Four Heart Chamber View 43

Fig 12: Illustration of the levels the four heart chamber 44

Fig 13: Illustration of the two perpendicular diameter used to drive

the Thoracic Circumference 45

Fig 14: Sonographic appearance of thoracic circumference with the

four chamber view of the foetal heart 45

Fig 15: Age distribution of the participants 51

Fig 16: Gestational age distribution of the foetus 52

Fig 17: Scatter diagram of mean TC against weeks of gestation 54

14

Fig 18: Scatter diagram of TC against BPD 58

Fig 19: Scatter diagram of TC against HC 59

Fig 20: Scatter diagram of TC against AC 60

Fig 21: Scatter diagram of TC against FL 61

Fig. 22: Sonogram of foetal thoracic circumference 80

15

LIST OF APPENDICES

Appendix i: Ethical clearance UMTH 73

Appendix ii: Participant consent form 74

Appendix iii: Table 8: mean values of BPD, FL, HC and TC

With GA. 76

Appendix iv: Table 9: comparison of mean values of TC and HC

against GA 78

Appendix v: Fig 22. Sonogram of foetal thoracic circumference

source manjucakesh 79

Appendix vi: Data capture sheet 80

Appendix vii: Raw date sheet 82

16

LIST OF ABBREVIATIONS

AA - Aorta

AC - Abdominal Circumference

ACR - American College of Radiology

AGA - Average Gestational Age

ASD - Atrial Septal Defect

BPD - Biparietal Diameter

CRL - Crown Rump Length

DA - Dutus Arteriosus

D1 - One Diameter

FE - Foetal Ear

FCC - Foetal Chest Circumference

FHS - Foetal Heart Structure

FL - Femur Length

GA - Gestational Age

HC - Head Circumference

HL - Humeral Length

IUGR - Intra Uterine Growth Restriction

LA - Left Atrial

LMP - Last Menstrual Period

MPA - Main Pulmonary Artery

MHz - Megahertz

17

OOD - Outer Orbital Diameter

RA - Right Atrial

TC - Thoracic Circumference

UMTH - University of Maiduguri Teaching Hospital

VSD - Ventricular Septal defect

YSD - York sac Diameter

18

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

The introduction of sonography by Donald and colleagues in 1958 is now

regarded as one of the major milestones of modern medicine (Johnson,

2005). For the first time it became possible to obtain information about

the foetus and its environment directly with a non-invasive diagnostic

procedure considered safe even when used repeatedly. In Nigeria there is

unprecedented growth in the application of ultrasound in general and in

obstetrics in particular due to its diagnostic/evaluation yield to physicians

and fetal gender determination (Johnson, 2005; Eze et al., 2010).

Ultrasound is useful in terms of accurate assessment of gestational age,

detection of abnormalities, evaluation of foetal growth and well being,

and guiding obstetricians and gynaecologist with in-utero diagnosis and

treatment (Johnson, 2005).

Diagnostic ultrasound plays key role in providing solution to obstetric

problems. In the developed world such as Japan and Great Britain,

ultrasound is also a screening test and the “routine-scan” is seen as part of

obstetrics care, capable of providing important information for improving

pregnancy management (Johnson, 2005). Accurate knowledge of

gestational age is prerequisite for best obstetric care, including evaluation

19

of fetal growth and management of preterm and post term pregnancies as

stated by Pekka and Vilho 2001 and Ola-oja,2005 . Every 30 seconds a

baby dies of preterm birth (Berghella, 2010). Over 1 million babies die in

the world every year due to problems related to being born too soon

(Requejo and Meriald, 2010). Failure to obtain accurate gestational age

can result to poor maternal and foetal outcomes (Konje et al, 2002) .

The estimation of GA is one the commonest indications for obstetrics

ultrasound investigation (Eze et al. 2010).Currently, real time scanners

which produce dynamic images of the moving fetus can be depicted on a

monitor screen. Very high frequency sound waves of between 3.5 to 7

megahertz (MHz) are generally used for this purpose. Repetitive arrays of

ultrasound beams scan the foetus in thin slices and are displayed on the

monitor screen. Movements such as foetal heartbeat and malformations in

the foetus can be assessed and measurements can be made accurately on

the images displayed on the screen. Such measurements form the corner

stone in the assessment of gestational age, size and growth in the foetus

(Johnson, 2005).

However, before the advent of ultrasound, assessment of foetal age was

purely by clinical evaluation and dependent on last menstrual period

(LMP) given by the patient and/or physical examination of the fundal

height of the pregnant women and Delee’s or quickening test. These

20

methods sometimes are inaccurate and unreliable due to the various

reasons (Agwu et al., 2008, Mongelli and Gardosi,2008). These includes

presence of Uterine leiomyoma coexisting with pregnancy resulting in

wrong fundal height measurement particularly when the date of the LMP

is not accurately known, as it is generally the case (Campbell et al.,

1985;Apfel and Green, 1999; Chuldleigh and Thilaganathan,2004; Agwu

et al. 2008). However, even when certain LMP is known it has been

shown that ultrasound is more accurate (predictive error 7.4-7.7 day) than

LMP (10 day) between estimated day of delivery and actual day of

delivery at 11-16weeks of gestation. Ultrasound is superior to LMP by at

least 1.7 day according to Pekka et al, 2001; Agwu et al,2008 ; Mongelli

and Gardosi, 2008)

With the introduction of ultrasound over five decades ago, the

assessment of foetal age has been improved, through the use of these

parameters; Yolk Sac Diameter (YSD), Crown Rump Length (CRL),

Biperiatal Diameter (BPD), Femur length(FL), Abdominal

Circumference (AC), Head Circumference (HC) are currently in use,

others are Humeral Length (HL),Outer Orbital Diameter(OOD), Foetal

Heart Structure (FHS), Foetal Ear (FE), whose accuracies are dependent

on trimesters and ease of obtaining measurement depending on the foetal

position (Pekka & Vilho, 2001;Ola-oja,2005). Foetal thoracic

21

circumference is rarely used as a predictor of gestational age and/or foetal

abnormalities in Nigeria, this may be due to lack of knowledge of fetal

thoracic measurements and also absence of standardised technique to

obtain such. Available foetal thoracic measurements for the estimating of

gestational age are one derived from Caucasian and United State of

America(USA) mix population which may be different from local place

understudy due to racial differences in FL as shown in other studies (De

La Verga,2008; Moongelli and Gardosi, 2008).Further limitation of the

previous study were; poor resolution of ultrasound machine used with

attendant challenges in foetal thoracometry, scanty description of

technique and small sample size.TC has advantage of easy of

measurement because it is not dependent on foetal lie, presentation, and

anatomical shape/size of foetal body as it affect other parameters such as

BPD,HC and FL.

This study was aimed to establish a nomogram by producing prospective

second and third trimesters foetal thoracic circumference dating

parameter and growth chart using modern real-time ultrasound equipment

in a Nigerian population.

1.2 Statement of the Problems

1. The accuracy of most biometric parameters in predicting

gestational age (GA) varies as pregnancy progresses, thus there is a

22

continuous search for other parameters in for a multiple

assessment in order to improve accuracy of GA

prediction(Ogunsina et. al, 2001).

2. The relationship between thoracic circumference and gestational

age in Nigeria foetus have not been investigated.

3. Present nomogram of thoracic circumference used in predicting

GA is based on Caucasian studies which may be inaccurate due to

possible racial difference, thus the need to derive a nomogram for

the Nigerian location.

4. The accuracy of the thoracic circumference in predicting GA has

not been compared with other biometric parameters like BPD, HC,

AC, FL in Nigeria population.

1.3 Objectives of the Study

The general objective of the study was to assess foetal thoracic

circumference as a predictor of gestational age.

Specific Objective

1. To measure the foetal thoracic circumference from 15weeks to 41

weeks with GA

2. To determine relationship between thoracic circumference and

gestational age.

23

3. To develop nomogram of the TC for the population under study

and compare the finding with Caucasian values

4. To determine foetal growth rate

5. To establish relationships and accuracies of prediction of GA

between TC and BPD, FL, HC

1.4 Significance of Study

1. The result of this study will be of immense help to the

sonographers, radiologists and obstetrician and gynecologists in

multiparameter prediction of GA. By providing a nomogram for

better estimation of gestational age for local populations studied

2. The result will be used as a predictor of gestational age of a fetal

thoracic sparing Intrauterine growth restriction (IUGR).

3. A standardized foetal thoracic circumference measurements

technique which will enable another biometric parameter for

gestation age estimation to be introduced.

1.5 Scope of the Study

The subjects were drawn from Nigerian populations and apparently

normal pregnant women whose obstetrics scan were done in Radiology

department, University of Maiduguri Teaching Hospital. The inclusion

criteria were all singleton foetuses with no abnormality visualized and

pregnant Nigerian women with no prolonged illness from their mid-

24

trimester (15-41weeks) at UMTH, northeast of Nigeria. The study

covered a period 39 months between August 2007 to October 2010.

1.6 Limitation of the Study

1. The study was cross-sectional and did not involve follow up of

cases.

2. The ultrasound equipment was not regularly re-calibrated after

break down, for accuracy of measurement. However, the machine

has installed software for quality assurance and re-calibrate

programmes and performs it regularly

3. A detail menstrual history was not taken, most women were not

certain of their Last menstrual period due to very high illiteracy

level and religious bias

4. The women were not scanned for sole purpose of dating

5. Composite dating model (BPD+FL+HC) was used instead of LMP

or Ovulation date or Conception date (Mclennan and schluter,

2008).

1.7 Literature Review

The estimation of gestational age (GA) is one of the commonest

indications for obstetrics ultrasound investigation (Rumark, et al., 2005).

In obstetrics ultrasonography, accurate prediction of GA is essential for

the proper management of the patient.

25

The most accurate way to calculate the gestational age is by knowing the

date of conception. However, most patients are unaware of the date of

conception. The earliest clinical measurement of GA is based on the

mother’s last menstrual period LMP (Apel and Green, 1999; Konjel et al.

2002). The first day of the last menstrual period (LMP) is used to

calculate the expected date of delivery (EDD). The LMP is unreliable (de

la Verga, 2002; Chuldleigh and Thilaganathan, 2004) due to the

following circumstances:

• When the date of the LMP is not accurately known especially

among illiterate women.

• When the menstrual cycle is not 28days long

• When the menstrual cycle is irregular

• When the patient has bled in early pregnancy.

Furthermore, about 40% of all pregnancies are not sure of their LMP (de

la Verga, 1999; Konjel et al. 2002), thus the need to have an accurate GA

of the foetal cannot be overemphasized. Studies comparing

ultrasonography estimation of the GA during the first trimester and

prediction of GA by means of LMP have shown sonography to be more

accurate than the later (Krishnendu, 1998, Pekka, 2001; de la Verga,

2002).

26

Ultrasound is a readily available, non-invasive and safe means of

evaluating foetal health, determination of gestational age, and assessing

the intrauterine environment. Several ultrasound parameters have been

used to estimate gestational age. The most commonly used parameters

are: in first trimester are Gestational sac diameter (GSD), Crown Rump

Length (CRL), while second and third triemester are the Biparietal

Diameter (BPD), Femur Length (FL), Head circumference (HC), and

Abdominal Circumference (AC), others are Humeral Length (HL), Outer

Orbital Diameter (OOD), Fetal Heart Structure, Fetal Ear, Fetal Thoracic

Circumference (TC), Fetal Thoracic Length (TL), Fetal Cerebelum (FC),

and Inner Orbital Diameter (IOD), Fetal Kidney Length (Davidson et

al,1981; Mayden et al., 1982; Mercer 1987; De la Verga ,2000; Nahid

et al, 2007; Yusuf et al., 2007; Mongelli and Gardosi 2008).

Measurement of a wide variety of parameters have been devised to

establish gestational age. The CRL GA estimation is between + 5 to ± 7

days accurate and the GSD is accurate in GA estimation by ±17 days

(Kurtz et al, 1999). However, as pregnancy advances to the second and

third trimester, the accuracy of estimating the GA by CRL and GSD

reduces (Krishnendu, 1998) thus the use of other biometric parameters

like AC, HC, BPD, FL and TC.

27

Ultrsononic assessment of gestational age by Horace Thompson in

Denver was the first to described in 1965 the measurement of the thoracic

circumference as a method for studying foetal growth. The measurement

had an accuracy of within 3cm in 90% of the patient (Woo, 2001). It was

reintroduces by Manfred Hangman in Bonn. TC was correlated with birth

weight of the foetus later when gray scale obstetric scans was developed

(Woo, 2001). Gamett and robinson in Sydney reported on measurement

of the foetal trunk area as a means to access foetal size in 1975. However,

the above lacked well defined landmark for consistency in measurement.

In 1976, the Hansmann group described further landmark for the

measurement of the thoracic circumference as a similar plane as that used

for the abdominal circumference. Circumference measurements of the

foetal trunk is considered superior to diameter measurements of the

former is less affected by the change in shape of the foetal body (Woo,

2001) . Fetal thoracic circumference as predictor of GA a new nomogram

was established by Chitkara et al ( 1987) in subject population of 570

normal women between 16 and 40 weeks gestation. A linear growth

pattern of thoracic parameters throughout gestation was noted.

In 100 normal pregnancy 13 to 41 weeks’ gestation foetal chest

circumference (FCC) versus gestational age and femur length were

constructed and a nomogram establish with FCC. Fetal chest

28

circumference measurement was useful in the antenatal prediction of

lettal or clinical severity pulmonary hypoplesia (Fong et al., 1988).

However, ultrasound machine used at that time cannot match the current

state- of- art ultrasound machines (2005) with higher resolution to assess

the foetal TC.

1.8 Operational Definition of Terms

Assisted Reproductive Technologies (ART) terminology (Zegers-

Hoschschid et al, 2006)

Clinical pregnancy: Evidence of conception from time of fertilization to

the end of the embryonic state 8 weeks after fertilization (Zegers-


Embryo: Product of conception from time of fertilization to the end of

the embryonic state 8 weeks after fertilization (Zegers-Hoschschid et al,

2006)

Gestational age: Age of an embryo or foetus calculated by adding

14days (2weeks) to the number of completed weeks since fertilization

(Zegers-Hoschschid et al, 2006).

29

Fertilization: The penetration of the ovum by the spermatozoa and

fusion of genetic materials resulting in the development of a zygote

(Zegers-Hoschschid et al, 2006)

Foetus: The product of conception starting from completion of

embryonic development (at 8 completed weeks after fertilization) until

birth or abortion (Zegers-Hoschschid et al, 2006)

Full term: A birth that takes place at 37 or more completed weeks of

gestational age. This includes both live births and stillbirths (Zegers-


Gestational sac: A fluid-filled structure containing an embryo that

develops early in pregnancy usually within the uterus (Zegers-Hoschschid

et al, 2006).

Pulmonary hypoplasia: is incomplete development of the lungs,

resulting in an abnormally low number or size of bronchopulmonary

segments or alveoli (Sanders &Winter, 2004)

Delee’s test: The first time the fetal heart can be heard with the foetal

stethoscope, usually at about 16 week’s gestation (Sanders &Winter,

2004).

Quickenine baby move 16 to 18 weeks (Sanders & Winter, 2004).

30

Quickening: The time when the mother first feels the baby move 16 to

18 weeks (Sanders & Winter, 2004).

Composite (average) gestational age: The mean of more than one

parameter used in estimating gestational age (BPD +HC+FL/3)

(Subbarao et al, 2003).

Intrauterine growth restriction: Previously known as intrauterine

growth retardation or IUGR, is a weight for a specific age below the 10th

percentile

31

Fig 1: IUGR Pictural diagram,

Source AIUM: American Institute of Ultrasound in Medicine, 2006),

ACR: The American College of Radiology, ACOG: The American

College of Obstetricians and Gynecologists.

32

CHAPTER TWO

THEORITICAL BACKGROUND

2.0 Embryology of Foetal Chest Development and Anatomy

2.1 Foetal Thoracic Wall

Vertebral column: the vertebral column is derived from the scleretomes

of somites. Each scleretome is divided into three parts; cranial, middle

and caudal. A vertebra is formed by the fussion of the caudal part of one

scleretome and the cranial part of the next sclerotome. It is therefore,

intersegmental in position (Singh and Pal, 2001).

Ribs: the ribs are derived from the sclerotomic mesenchyme that forms

the vertebral arches. These extensions are present not only in the thoracic

region but also in the cervical, lumbar and sacral regions. They lie ventral

to the mesenchymal basis of the transverse processes with which they are

continuous. In the thoracic region, the entire extension (called the

primitive costal arch) undergoes chondrification to form the ribs (Singh

and Pal, 2001).

Sternum: the sternum is formed by the fusion of two sternal bars or

plates that develop on either side of the midline. The fusion of the two

sternal bars first occurs at the cranial end (Manubrium) and proceeds

caudally. The Manubrium and the body of the sternum are ossified

33

separately. The Xiphoid process ossifies only late in life (Singh and Pal ,

2001).

The diaphragm: the diaphragm is a partition that separates the thoracic

and abdominal cavities. The pericardial and pleural are above it, whereas

the peritoneal cavity is caudal to it. The development of the diaphragm is

therefore, intimately related to the development of these cavities. (Singh

and Pal, 2001).

According to Moore and Persaud (2003), the diaphragm develops from

four structures; Septum transversum, Pleuroperitoneal membranes, Dorsal

mesentery of oesophagus, Muscular in growth from lateral body walls.

The transversum is established in the 4th week. The diaphragm descends

to the thoracic level in the 6th week and parts of it reach the lumbar region

by the 3rd month.

The heart: the development according to Singh and Pal (2001) is, the

heart develops from the splanchnopleuric mesoderm related to that part of

the intra-embryonic coelom that forms the pericardial cavity. This

mesoderm is the cardiogenic area.

The heart is the most susceptible to teratogens between 3 and 6 weeks. It

can be affected up to 8th weeks. Clusters of blood and vessels forming

cells (angioblastic islands) appear in the 3rd week. At the end of this week

34

(18th day) the cardiogenic area, heart tubes and pericardium have formed.

At the end of the 22nd day, the head fold is established: the heart and

pericardium now lie ventral to the foregut. At this stage, the heart tube

shows its main subdivisions. The heart begins to beat in the 4th week.

Septa in the heart form between the end of the 4th week and the beginning

of the 7th week. The spiral septum is formed in the 5th week. Aortic arches

are established during the 4th to 5th weeks. Veins also begin to be formed

at the same time (Moore and Persaud, 2003).

2.2 Anatomy

According to Moore and Dalley (1999), the thorax (chest) is the superior

part of the trunk between the neck and the abdomen. It is formed by the

12 pairs of ribs, sternum (breast bone) costal cartilages and 12 thoracic

vertebrae. These bony and cartilaginous structures form the thoracic cage

(rib cage) which surrounds the thoracic cavity and supports the pectoral

(shoulder) girdle.

35

2.3.0 Hereditary Defect of Fetal Chest

2.3.1 Dextrocardia

The heart lies on the right side of the thorax instead of the left. It is

caused because the heart loops to the left instead of the right. It may

coincide with situs inversus, a complete reversal of asymmetry in all

organs.

2.3.2 Atrial Septal Defect (ASD)

In this acyanotic heart defect, an opening between the right and left atria

allow blood to flow from the left to the right, resulting in ineffective

pumping of the heart, thus increasing the risk of heart failure.

There are 3 types

Fig. 2: Foetal chest Sonogram courtesy of Dr. Prem Chand, Pakistan

Fig. 3: foetal ribs and spine sonogram courtesy of Dr. PK Srivastava,India, and Dr. Ravi

36

a. The most superior portion is the sinus venosus portion of the

septum. Defect in this portion are associated with partial

anomalous pulmonary venous return

b. The midportion (area of the fossa ovalis) of the septum is the

secundum portion. This is the most common area for the defect to

occur. Because the foraman ovale is patent in fetal life, it is

difficult to diagnose a defect in this portion prenatally

c. The most inferior portion is the osteum premium portion. A defect

in this portion is associated with atrioventricular septal defect.

2.3.3 Ventricular septal defect(VSD)

In a VSD, the most common acyanotic heart disorder an opening in the

septum between the ventricles allow blood to shunt between the left and

right ventricles. This results in ineffective pumping of the heart and

increases the risk of heart failure.

Morphologically, the ventricular septum is divided into 2 segments: the

membranous which is the small thin portion inferior to the aortic root and

the muscular portion is divided into 3 portions:

a. The inlet portion which is at the level of the atrioventricular valves

b. The outlet or infundibular portion which is the anterior portion at

the level of the semilunar valves

37

c. Muscular septum which extends from the membranous portion of

the apex

There can be more than one ventricular septal defect in the same or

different portions of the septum. They are often associated with other

types of congenital heart disease.

A combination of four cardiac defects: ventricular septal defect, right

ventricular outflow tract obstruction (pulmonary stenosis), right

ventricular hypertrophy and dextroposition of the aorta, with overriding

of the VSD. Blood shunts from the right to the left through the VSD,

allowing unoxygenated blood to mix with oxygenated blood resulting in

cyanosis.

2.3.4 Trunkus arteriosus

This consists of the following

a) Outlet VSD

b) Single semilunar valve

c) Common arterial root that overrides the ventricular septum

The ventricular root usually originates from the 2 ventricles equally. It

can originate more from one ventricle than the other. The truncal valve

(semilunar valve) may have one to six leaflets. It can have normal flow

regurgitation or stenosis.

38

There are 3 types of truncus arteriosus. In all 3 types, the pulmonary

artery comes off the aorta. It can be the main pulmonary artery or one or

both branches of the pulmonary artery. The position of their origin

determines the type

2.4.0 Sonographic Assessment of Thoracic Circumference as

Prediction of Gestational Age

2.4.1 Thoracic Circumference

However, foetal thorax would be a better part of the foetal trunk to be

localized. In 1973, it was described the uses of the thoracic circumference

in the assignment of foetal growth but the landmark for the measurement

was not consistent. Garrett and Robinson (1971) in Sidney had also

reported on the measurement of foetal trunk area as a means to assess

foetal size. They had also reported in grey scale obstetric at the

International Biomedical Engineering meeting in Melbourne in the same

year. The method did not catch on until the appearance of Grey scaling in

other machines (Glasgow, Denver) and in particular Octoson in 1975. In

1976, the Hansmann group (Kugener et al., 1976) described landmark for

the measurement of the thoracic circumference. It was a similar plane as

that used for the abdominal circumference.

39

Thoracic dimensions can be assessed by measuring the thoracic

circumference at the level of the four heart chamber view of the heart

(Dugoff et al,. 1996). A study by Chitkara et al, 1987 made use of this

land mark to produce normal values of the thoracic circumference in the

prediction of gestational age.

Fig 4: Four-chamber sonograms colour Doppler. During diastole,

flow is visualized entering from both the right and left atria (RA, LA)

into the right and left ventricles (RV, LV) and the flows are

separated by the interatrial and interventricular septum.

Source: De Vore, 2009

Fig 5: Four heart chamber view and chest circumference of foetus

40

2.4.2 Examination of the foetal heart

The standard views to be obtained when scanning the heart are:

Four chamber view

The four heart chamber view is obtained by taking a longitudinal section

of the fetal thorax and then angling the transducer in such a way to fill till

the four chambers are seen (Kuldeep and Narenda,2002;).In this view, the

following are seen.

1. The prominent Eustachian valve within the right atrium and the

valve of the foramen ovale flapping within the left atrium.

2. The atrioventricular valves are seen with tricuspid valve lying

closer to the cardiac apex than the mitral valve

3. The right ventricle is situated beneath the anterior chest wall. The

moderator band is in the right ventricle and the walls are

trabeculated. The left ventricle walls are much smoother

4. The atrioventricular valve opens during diastole

The basic cardiac examination includes a 4-chamber view of the fetal

heart. If technically feasible, an extended basic cardiac examination can

also be attempted to evaluate both outflow tract. When the ultrasound

beam is directed perpendicular to the chest of the foetus and angling the

transducer in such a way that four chambers of the heart are identified.

These chambers consist of the right and left atrial and ventricular

41

chambers, with their respective valves that connect the atrial and

ventricular chambers.

2.5. 0 Sonographic Assessment of other Parameters used to

Determine the Gestational Age

There are numerous parameters established that can be used to determine

foetal growth. The parameters used in determining gestational age are;

crown-rump length, head circumference, abdominal circumference,

biparietal diameter, occipito-frontal diameter and femur length. Others

are; foetal neck circumference, foetal kidney length, foetal humerus,

foetal liver and axial transverse diameter of the fetal foramen magnum.

Some of these parameters not only determine foetal growth but weight as

well.

2.5.1 The Crown Rump Length (CRL)

The original definition of the CRL was by Mall in 1967. The CRL is the

sitting height, midbrain to the lowest point of breech. For ultrasound, the

CRL is defined as the longest length excluding the limbs and yolk sac

(Westerway et al., 2002). In dating examination performed in the first

trimester, the CRL is the optimal method of establishing fetal age

(Sanders et al., 1998). CRL is the measurement of choice less than 12

weeks and CRL measuring discrepancies are more from 12 weeks

gestation (Westerway et al., 2002)

42

2.5.2 Biparietal Diameter (BPD)

The BPD remains the standard against which other parameters of

gestational age are compared. The BPD is measured from the outer

surface of the anterior parietal bone to the inner surface of the posterior

parietal bone (Shepard and fill 1982; Hadlock et al., 1982 and Beigi and

Zarrinkoub, 2000).The anatomical landmark used to ensure accuracy and

reproducibility of the measurement include: midline falx, the thalami

symmetrically positioned on either side of the falx and visualization of

the septum pellucidum at one of the fronto-occipital distance. The

variability of BPD in predicting menstrual age after 28 weeks is too great

to be reliable (Sabbagha et al., 2003).This is the most reliable method of

estimating gestational age between the 12th and the 26th weeks. After that,

its accuracy can be lessened by pathological disorders and biological

variations that affect fetal growth.

Fig. 6: Foetal skull with Biparietal diameter sonogram (calipers) at

25 menstrual weeks. T, thalami; CSP, cavum septum pellucidum.

43

The BPD is the distance between the parietal eminences on either side of

the skull and is, therefore, the widest diameter of the diameter of the skull

from side to side using scans at different angles, the transverse section

will be recognized when the shape of the fetal is ovoid and the midline

echo from the falx cerebri is interrupted by the cavum septi pellocidi and

the thalami. When this plane is found, the gain on the ultrasound unit

should be reduced and measurement made from the outer table of the

proximal skull (the part nearest to the transducer) to the inner table of the

distal skull (the part farthest away from the transducer). The soft tissues

over the skull are not included. This is the “leading edge-to-edge”

technique (Ugwu et. al, 2007). This parameter has a variability ranging

from 1.5 to 2.7weeks depending on the period gestation (Subbarao et al.,

2003). The BPD (fig 6)was measured by from the outer edge of the skull

for the edge near to the transducer and then the inner edge of the skull

vault(Altman et al., 1997).

2.5.3 Head Circumference (HC)

It is the length of the outer perimeter of the cranium. It is measured using

the same landmark with the BPD (Hill et. al, 1991) The HC is more

accurate than the BPD in predicting gestational age (Benson and

Doubilet, 1991).This is more accurate predictor of gestational age when

the skull shape is normal (Subbarao et. al, 2003). If the cephalic index is

44

within the normal range, the BPD is acceptable as an estimate of

gestational age. If the cephalic index is outside this range (less 70 or

greater than 86), the measured BPD should not be used to determine the

gestational age .Instead the head circumference can be used(Ugwu et. al,

2007). On some ultrasound machines, this may be measured directly, it

can also be calculated(Ugwu et al., 2007). The head circumference(HC)

was measured by tradeball on the outer skull vault.

Fig.7: Head circumference sonogram

Measurements to obtain the cephalic index: outer-to-outer distance at the

level of the biparietal diameter (B) divided by occipital-frontal diameter

(o) multiplied by 100.

Head circumference = (BPD + Fronto-occipital diameter) ×1.57

Cephalic index = BPD × 100 Fronto-occipital diameter

45

A study conducted by Ugwu et al. (2007) on the Ibo tribe of Nigeria

revealed the Foetal Cephalic Index as 85.92±4.88.

2.5.4 Abdominal circumference (AC)

It is the length of the outer perimeter of the abdomen taken on axial plane

at the level of the umbilical vein-ductus venosus complex (Hadlock et al.,

1982). The variability in predicting menstrual age values associated with

a given abdominal circumference measurement is broader than that

observed with the foetal BPD (Hadlock et al., 1982). AC is less accurate

than BPD in establishing gestational age (Subbarao et al, 2003). AC is

used to detect intrauterine growth disturbances, the measurement must be

taken at the level of the fetal liver which is very sensitive to deficient

nutrition. It is most important that the scan shows a cross-section of the

foetus that is as round as possible. Make sure that the correct level is

being measured; look for the umbilical part of the left portal vein. The

measurement must be made on a trans-axial plane, where the umbilical

portion of the left portal vein enters and is entirely within the liver. The

liver should be short, not elongated. If it is also too long, the axis is too

oblique. When you have a scan at the correct level, measure the antero-

posterior (AP) and transverse diameters. A medium gain setting should be

used and measurement must be from the outer edge of the foetal abdomen

46

on one side to the outer edge on the other side. Calculate the abdominal

circumference by using the formula below.

AC = (Antero-posterior diameter + transverse diameter) × 1.57

If the abdominal circumference is less than the fifth percentile, it is small

and if greater than 95th percentile, it is large((Ugwu et al., 2007).

2.5.5 Femur length

The femur length is measured from the major trochanter to the lateral

condyle along the axis of the central shaft exclusive of epiphyses. The

long shaft of the femur is placed exactly perpendicular to the ultrasound

beam (Beigi et al., 2000). Overall, it is mostly used in the third trimester

because the BPD becomes less accurate/ reliable owing to the

engagement of the fetal head in the mother’s pelvis. This measurement is

as reliable as BPD in the determination of gestational age and it can be

used from 12 weeks to term. It is however necessary that measurement is

done when the two ends of the femur are obtained clearly and the outline

of the bone is straight (Dugoff et al., 1996). Find a projection that shows

a transverse section of one of the long bones, and then scan at 900 to this

to obtain a longitudinal section (Ugwu et. al, 2007).

47

Fig 8. Correct femur length outline sonogram

The markers outline the distal femoral epiphysis. FL, femur length

Fig. 9a: Incorrect the femur (f) length sonogram should not be

measured unless it is perpendicular to the transducer.

48

Fig.9b: Incorrect bowed femur length sonogram

The markers outline the appropriate length of the femur. (A) Curved

medial (M) border (arrows). (B) Straight lateral (L) border (arrows).

2.5.7 Other parameters

2.5. 7.1 Fetal kidney length

This is measured from the outer border of the upper pole to the outer

border of the lower pole of the kidney. Kidney length is a more accurate

method of determining the gestational age than fetal biometric indices,

BPD, HC, AC and FL between 24 and 38 weeks gestation (Konje et al.,

2002).

2.5.7.2 Humerus length

Other parameters such as Humerus length (HL) (Mastrobattista et al.,

2004), fetal spine length (Ulm et al., 1999), Thoracic length and

circumference (Chikara et al., 1987), neck circumference (Sherer et al.,

2007).

49

2.5.7.3 Average Gestational Age

This refers to the mean of more than one parameter used in estimating

gestational age. Each parameter used has a certain degree of variability

but a combination of more than one parameter reduces the variability in

weeks. The table below by Subbarao et al.(2003) illustrates the below

Table 1: Age Variability in Weeks

PARAMETERS 6-14 12-18 24-30 36-42

CRL ±0.4 - - -

BPD - ±1.2 ±2.2 ±3.2

FL - ±1.6 ±2.8 ±4.0

HC - ±1.2 ±2.1 ±2.3

AC - ±1.7 ±2.2 ±3.0

BPD,HC,AC,FL - ±1.1 ±1.8 ±2.3

2.6.0 Other Radiological Methods of Fetal Dating (Other Imaging

Modalities used for Foetal Dating)

2.6.1 Plain film

Here radiographic projections such as PA 200 cephalad in early

pregnancy centered to the tip of the coccyx. In advanced pregnancy, PA

and AP, centered respectively to the L4 and midpoint between the iliac

crests. The PA oblique could also be used.

50

2.6.2 Amniography or fetography

Here the amniotic fluid surrounding the fetus is replaced by a contrast

agent and radiographs taken. These are all obsolete and have been

superseded by ultrasound

2.6.3 Magnetic Resonance Imaging (MRI)

MRI is used as an additional investigation, mostly to detect foetal

anomalies.

2.7.0 Clinical methods of Estimating Gestational Age (Non-

Radiological Methods) According to Moongelli and Gardosi,

2008

2.7.1. Naegle’s Rule, Parikh’s Formular and the Obstetric Wheel

(Menstrual History)This is the most common method of pregnancy

dating. The expected date of delivery (EDD) is calculated by Naegele's

Rule is a standard way of calculating the due date for a pregnancy. The

rule estimates the expected date of delivery (EDD) by adding one year,

subtracting three months, and adding seven days to the first day of a

woman's last menstrual period (LMP).

Example:

LMP = 8 May 2009

+1 year = 8 May 2010

-3 months = 8 February 2010

+7 days = 15 February 2010

51

The result is approximately 280 days (40 weeks) . This method assumes

the patient has a 28 days menstrual cycle with fertilization occurring the

14th day, and many others are not certain of their last period. In addition,

early pregnancy bleeding or recent use of contraceptives may lead to an

incorrect assumption of the date of ovulation. Naegele's Rule assumes an

average cycle length of 28 days, which is not true for everyone.

However, Parikh's Formula is a calculation method that considers

considers cycle duration EDD is calculated using Parikh's Formula by

adding 9 months to LMP, subtracting 21 days, then adding duration of

previous cycles (Parikh , 2007). The obstetric wheels consist of an outer

wheel that has markings for the calendar and an inner, sliding wheel with

weeks and days of gestation.

2.7.2 Other Non-Radiological Methods (Blood, Pelvic and/or

Abdominal Palpation)

1. Methods such as measurement of the fundal height, measurement

of maternal abdominal circumference.

2. Date of pregnancy test: Determination of the blood HCG (human

chorionic gonadotrophin) concentration (in early pregnancy) have

all been replaced by ultrasound owing to lack of accuracy and

reliability.

52

3. Perception of foetal movement by the patient is called quickening,

is a relatively late sign of pregnancy occurring at 19-21 and 17-19

Weeks’ gestation in nulliparous and multiparous women

respectively.

4. Pregnancy following assisted reproduction technique, the GA of

pregnancies resulting from in vitro fertilization can be precisely

calculated from the time embryo implantation

53

CHAPTER THREE

RESEARCH METHODS

3.1 Introduction

3.2 Research Design

The research was a prospective cross sectional study. The human subjects

chosen for the study were consented pregnant women from 2nd and 3rd

trimesters referred for obstetric scan from the clinic at University of

Maiduguri Teaching Hospital (UMTH) who met the inclusion criteria.

3.3 Setting of Study

The study was conducted at University of Maiduguri Teaching Hospital,

Borno State, North eastern Nigeria. University of Maiduguri Teaching

Hospital (UMTH) in 1974 the defunct North East government conceived

the construction of a specialist Hospital in Maiduguri Nigeria, the state

capital. The federal military government later took over and completed

the project. The first patient was admitted on 18th February, 1982. The

hospital covers a landmark of about 64,773 hectare. The hospital was

designated a centre of excellence in immunology and infectious diseases

by the federal government of Nigeria. It is 540 bedded hospital.

The UMTH main functions are Provision of quality tertiary health care

services, Provision of training of medical and other health professionals

and Research. The hospital serves the North East sub-region of the

54

country, comprising (Adamawa, Bauchi, Borno, Gombe, Taraba and

Yobe) and entire nation as well as a sizable number of people in

neighboring countries, Cameroon, Chad and Niger Republics.

Radiology department facilities

The department has different imaging modalities and therapeutic units

such as MRI, CT-Scan, Mammography, C-Arm, fluoroscopy,

conventional x-ray and interventional angiography, ultrasound unit which

are all Vamed projects (2005). Furthermore, it is regional

ultrasonography training centre for West Africa in collaboration with

Jefferson ultrasound research and education institute (JUREI),

Philadelphia, U.S.A.

3.4 Study Population

A sonographic assessment of uncomplicated singleton pregnancies from

15-41 weeks’ gestation was done. The period of gestation from which

measurements were obtained were divided in to 27 weeks. Maiduguri

consist of many tribes ,however 28 tribes participated in the study

including three major tribes Igbo, Hausa and Yoruba.The major tribe is

Kanuri .Two major religion are predominant Christians and Muslims in

this region. The social life of the people are characterized by early

marriage by the female from 15 years old and polygamy is a common

practice.

55

3.5 Determination of Sampling Size and Sampling Technique

Sample size, n = Z2P (1-P) / d2 Taylor’s formula

n = minimum sample size

Z = 1.96 standard normal deviation usually set at 95%

confidence level

P = estimated population. Since this proportion is not

known for the target population, a value of 50% (0.5)

is assigned to obtain maximum value for P

d = absolute precision required on either size of the

proportion 5% (0.05)

n = (1.96)2 x 0.5 (1 – 0.5) = 384 (0.05)2

Hence a sample size of 907 participants were chosen for the study which

was greater than calculated minimum sample of 384. This allows for

reduction of sampling error. The sampling technique used was convenient

sampling, this entails any eligible pregnant women referred for fetal

dating ultrasound scan that met the inclusion criteria was included for the

study.

3.6 Sources of Data

The data was a primary sources. These are measurement of Nigeria

populations of derived foetal thoracic circumference, the biparietal

diameter (BPD), femur length (FL), abdominal circumference (AC) and

56

head circumference (HC) of foetus of 907 pregnant women other sources

of data and information which are secondary are from books and journals

of Caucasians such as TC for comparative analysis.

3.7 Ethical Consideration

The ethical committee provided clearance for this study (approval

number ADM/TH/75/VOL.II and date 08/08/2007) and all women

provided written consent to participate.

3.8 Recruitment of Subjects

The subjects were pregnant Nigerian women from their mid trimester of

pregnancy (15 weeks to 41 weeks) who were referred for ultrasound

investigation.

Inclusion criteria

• Pregnant women at their mid-trimester (15weeks -41 weeks )

• No history of prolonged maternal illness

• No vaginal bleeding

• Singleton pregnancy

• No other abnormality visualized on either maternal or fetal parts

ultrasonically.

57

Exclusion criteria

• Women who take drugs and substance abuse – smoking, alcohol,

anti-hypertensives, fertility drugs.

• Women with uterine and placental anomalies and abnormalities –

Bicornuate uterus, uterine myomas, septate uterus.

• Fetal infection.

• Maternal conditions: Diseases – diabetes and Hypertension

women.

3.9 Method of Data Collection

The age, tribe and parity of the women were also recorded on data

capture sheet. The data was collected by taking measurements of two

fetal thoracic diameters at right angle to each other and later thoracic

circumference derived with a formulae(TC=��{ (D12+D2

2)/2}). Those

measurements were taken at the level of the four heart chamber view and

during diastole. Apart from fetal thoracic diameters, the BPD, HC, AC

and FL were also measured.

58

Fig. 10: Sonographic appearance of derived thoracic circumference

3.9.1 Instrumentation

Measurement were obtained with a modern real-time ultrasound

(ALOKA prosound 3500, produced in Japan) two-dimensional real-time

gray scale ultrasound machine with good resolution equipment. The

equipment less than 30 months old from date of manufacturing (2005)

was used, with a 3.5MHz transabdominal curvi-linear transducer. The

electronic calipers calibrated for an assumed ultrasound velocity of

1540m/s in soft tissue. The equipment has a calibration which reading of

the GA as measurements were made and give a composite (average) GA.

3.9.2 Patient Preparation

1. Full urinary bladder was achieved by giving 1 litre of water

ingested within 15 to 20 minutes time period to the subject.

D1

D2

59

2. If for any reason the patient cannot have fluids, sterile water were

used to fill the bladder through a Foley’s catheter by obstetrician or

Radiologist.

3. The patient were positioned supine with 3.5MHz transducer.

4. The patient breathing technique were normal respiration.

3.9.3 Scanning Protocols

The procedure was explained to each patient and the subject was asked

to take a litre of water in order to achieve a full bladder. Once a patient

has full bladder, the examination was commenced with transabdominal

scan. A research assistant (experienced 19 years, registered AIUM

sonographer) was used. Technique adopted was

the STANDARD ultrasound examination of the foetus of these three

organizations (AIUM–ACR-ACOG, 2007). The fetus were scanned at

various tomographic planes for best technique to demonstrate the thoracic

circumference of the foetal chest dimensions, after applying Ultrasound

gel on the abdomen. The foetuses were scanned in both longitudinal and

transverse axis using transabdominal probe at plane to identify the lie

and presentation of the foetus. The foetal well being accessed by

examining the fetal heart and other indicators.

60

3.9.4 Scanning Technique to Demonstrate Fetal Thoracic

Circumference

The patient lies either supine (in early pregnancy) or in Foyler position

i.e. 55o caudad angulation on the examination couch. A general survey

(sweep) using a 3.5MHz transducer was initially performed to ensure

that the foetus, the placenta and the uterus were normal. The foetal four

heart chamber view was used as landmark for measurement of the fetal

thoracic circumference according to De Vore, 2009. The four chambers

were identified when the ultrasound beam was directed at right angle to

the foetal chest (Chitkara et. al. 1987; De Vore, 2009).

Fig. 11: Imaging the four-chamber view is accomplished by directing the ultrasound beam perpendicular to the fetal chest. At this level, the four-chamber view is identified. This view contains the right atrium (RA), left atrium (LA), right ventricle (RV) and left ventricle (LV). Source: De Vore, 2009

To obtain the four chamber view of the fetal heart, the long axis of the

spine was identified. Then the transducer rotated 900 at the level of the

61

foetal thorax. Or from the abdominal circumference, the transducer was

gradually angled cephalad. Sliding up towards the head until the required

four heart chamber view was obtained (Chikara al. 1987,Sanders et al.,

1998). In the four chamber view one sees the prominent Eustachian valve

within the right atrium and the valve of the foramen ovale flapping within

the left atrium (Kuldeep et al ., 2002). The atrioventricual valves are seen

with the tricuspid valve lying closer to the cardiac apex than the mitral

valve (Kuldeep et al., 2002).

The image was frozen during diastole i.e. when both the tricuspid and

mitral valves are open. The data were obtained by measuring two foetal

thoracic diameters at right angle to each other than thoracic

circumference was derived.

Fig. 12: This illustrates the level that the four-chamber view is imaged (green). The main pulmonary artery (MPA), ductus arteriosus (DA), and the aorta (AA) are not imaged at the level of the four-chamber view. SVC=superior vena cava, RV=right ventricle, RA=right atrium, LV=left ventricle, LA=left atrium Source: De Vore, 2009

62

One diameter (D1) was taken along the ventricular septum. The other (D2)

was taken along the line joining the mitral and tricuspid valves. Both are

taken from outer to outer fetal thoracic surfaces in such a way that they

are at right angle to each other as illustrated in the diagram below.

Fig.13: Illustration of two diameters used to drive the thoracic circumference

Fig. 14: Sonographic appearance of thoracic circumference with the

four-chamber view of the fetal heart

Thus from D1 and D2The foetal thoracic circumference was derived using

this formular.

TC=��{ (D12+D2

2)/2}

D1

D2

Heart

Fetal thoracic circumference

D1

D2

Thoracic circumference

63

It was assumed that the thoracic at the four heart chamber view is either

circular or oval in shape as the foetal head at the standard landmark for

BPD’s measurement. These formular applied to the calculation of the

head circumference were also applied to the foetal thoracic

circumference.

Other parameters measured

The BPD the proximal edge to the proximal edge of the deep border

(outer-inner) (Altman et al., 1997; Ugwu et. al, 2007) at the standard

landmark as described in chapter two.

The head circumference (HC) was measured by tradeball on the outer

skull vault (Ugwu et. al, 2007).

Abdominal circumference (AC) it is the length of the outer perimeter of

the abdomen taken on axial plane at the level of the umbilical vein-ductus

venosus complex (Hadlock et al., 1982).

The femur length was measured from the major trochanter to the lateral

femoral condyle along then longest axis of the central shaft exclusive of

the epiphyses as described by (Beigi et al., 2000)

The following information items were collected from each of obstetric

case scanned in data capture sheet.

64

1. Patient age, tribe, parity

2. Biparietal diameter (BPD)

3. Derived Fetal thoracic circumference (TC)

4. Fetal head circumference (HC)

5. Fetal femur length (FL)

6. Abdominal circumference (AC)

7. Average gestational age (AGA)

The measurement were taken from the 15th -41 weeks’ of GA .

3.10. Dating Model

Due to some factors such as faulty memory, bleeding in early pregnancy

and the use of contraceptives the LMP as a gold standard has several

potential of inaccuracy (Campbell et al., 1985; Apfel and Green, 1999;

Chuldleigh and Thilaganathan,2004;Agwu et al. 2008). Also with the

illiteracy of many women in the locality of the study, which the majority

doesn’t know their LMP. For these reasons the LMP was not used. Rather

the measurements were correlated to the composite (average) gestational

age obtained from the BPD, HC, AC and FL. This is because the

combination of more than one parameter increases the reliability,

sensitivity and accuracy of foetal biometry (Mercer et al., 1987; Ogunsina

et. al., 2001; Subbarao et al., 2003)

65

3.11 Method of Data Analysis

The analysis of the data involved the use of test statistics. The package

SPSS version 17.0, was used in the analysis. All comparative tests were

performed at 5% significant level. The analyses were done using both

descriptive and inferential statistics. Descriptive statistics used include

frequency, standard deviation, percentage, means, range geometric mean,

tables and charts were used to describe the data Inferential statistics used

include Student ‘t’ test was used to test the average means values and

Pearson correlation coefficient was used to show relationships between the

TC and BPD, HC,AC, FL and weeks of gestation. Geometric mean was used to

calculate the growth rate.

66

CHAPTER FOUR

PRESENTATION OF RESULTS AND DISCUSSION

4.0 Introduction

The results obtained from the measurements were analysed and

presented. The mean of the several biometric parameters were measured

were analysed and presented. The mean measurement were BPD, FL,

HC, AC and TC. The mean values of the measured biometric parameters,

BPD, FL, HC,AC, TC were compared and correlated with each other, to

ascertain their statistically acceptability.

4.2 Results

4. 2.1 Demography

Descriptive analysis of data

A total of 907 singleton women participants were employed in the study. The

TC values ranged from 9.159cm to 32.168cm within 15-41 weeks of as

gestation demonstrated in table 4.Twenty eight different tribes were involved

in the study, the major tribes were Kanuri 299(30.97%), Igbo176

(18.07%),Fulani80(8.82%),Hausa32(3.80%), Marghi 17(1.87%) as

shown table 2. Their age ranged from 15 to 42 (mean age is 32).

67

Table 2: Distribution of the participants according to tribe S/NO. TRIBE FREQUENCY PERCENTAGE

1. Babur 9 0.96 2. Bade 8 0.94

3. Bago 9 0.96

4. Baseyap 9 0.97

5. Bura 13 1.93

6. Chibok 9 0.95

7. Daba 8 0.94

8. Dajju 8 0.94

9. Fulani 80 8.82

10. Hausa 32 3.80

11. Hidi 9 0.96

12. Idoma 21 2.31

13. Igala 8 0.93

14. Igbo 176 18.07

15. Jukun 8 0.94

16. Kanakura 9 0.95

17. Kanuri 299 30.97

18. Kilba 8 0.94

19. Kuteb 6 0.71

20. Mandara 10 0.82

21. Marghi 17 1.87

22. Michika 9 0.97

23. Nakere 8 0.94

24. Shuwa 43 4.12

25. Tiv 10 0.72

26. Waja 8 0.94

27. Yabe 8 0.94

28. Yoruba 65 7.17

Total 907 100 The majority of pregnancies were between 30 and 40 weeks old

(151=46.6%). The distribution of the scanned women according to the

pregnancy age is illustrated in fig 15

68

Fig 15: Age distribution of the participants

This shows that majority of women age group scanned (20-24 age)

Was 88.07%, while the least age group was 40-42 age 6.03%

�

��

��

��

��

��

��

��

�

�

��

��

��

��

69

Fig 16: Gestational age distribution of foetus in weeks

This shows that majority of the group foetal gestational age measured

was 46% (30-40). While the least group of foetal gestational age was

22% (12-20).

�

��

��

��

�

��

��

��

��

��

��

��! ��"��

70

Table 3: Mean values of TC matched against GA

S/N G.A (WEEKS) FREQUENCY TC MEAN VALUES(cm)

S.D.

1 15 16 7.9357 0.243 2 16 13 8.812 0.398 3 17 24 9.795 1.091 4 18 24 12.310 0.785 5 19 14 12.863 0.726 6 20 32 14.054 1.798 7 21 45 15.330 1.455 8 22 62 15.342 1.249 9 23 26 16.857 0.293 10 24 39 18.212 1.942 11 25 59 18.508 0.961 12 26 41 18.589 0.950 13 27 44 20.964 1.190 14 28 22 20.971 1.664 15 29 48 22.327 1.254 16 30 32 23.336 1.080 17 31 22 24.871 2.468 18 32 11 25.771 0.903 19 33 18 25.929 0.000 20 34 52 26.104 0.926 21 35 72 26.891 1.811 22 36 48 26.924 1.006 23 37 65 27.137 2.224 24 38 31 27.160 0.846 25 39 14 27.410 2.179 26 40 16 31.271 0.162 27 41 17 32.381 0.162

The table above showed the measured mean values of TC matched

against GA. The frequency distribution and their standard deviations.

71

Fig17: Scatter diagram of mean TC against weeks of gestation.

The equation of the line of ‘best fit’ is Y=4.65 + 1.13TC .Where Y is the

average gestational age and X is the fetal thoracic circumference There is

a high correlation and statistically significant correlation was observed

between the weeks of gestation and the TC (r2=0.974, P�0.001)

��

��

�

�

��

��

��

��

��

��

�

�

� � ��

# �� !��! ��"��

$��"��% ��!��!��

��

��

72

TABLE 4: Comparism between 50th percentile TC in Nigerians

(derived nomogram) and the caucasians

The above showed the comparism of TC in Nigeria an the Caucasians at

50th percentile

S/N GA (WEEKS)

Number of measurements (Caucasian)

TC (cm)Caucasian 50 percentile

Number of measurements (Nigerian)

TC(cm)Nigerian derived 50 percentile

1 16 06 9.1 13 8.812

2 17 22 10.0 24 9.795

3 18 31 11.0 24 12.310

4 19 21 11.9 14 12.863

5 20 20 12.8 32 14.054

6 21 30 13.7 45 15.330

7 22 18 14.6 62 15.342

8 23 21 15.5 26 16.857

9 24 27 16.4 39 18.212

10 25 20 17.3 59 18.508

11 26 25 18.2 41 18.589

12 27 24 19.1 44 20.964

13 28 24 20.0 22 20.971

14 29 24 21.0 48 22.327

15 30 27 21.9 32 23.336

16 31 24 22.8 22 24.871

17 32 28 23.7 11 25.771

18 33 27 24.6 18 25.929

19 34 25 25.5 52 26.104

20 35 20 26.4 72 26.891

21 36 23 27.3 48 26.924

22 37 22 28.2 65 27.137

23 38 21 29.1 31 27.160

24 39 07 30.0 14 27.410

25 40 06 30.9 16 31.271

73

4.3 Inferential Analysis

4.3.1 Test of Hypothesis

H0: There is no significance difference between the mean thoracic

circumference of Nigerian from that of the Caucasian population.

HI: There is significance difference in the mean thoracic circumference

of the Nigerian from that of the Caucasian population.

Student T Test: Two tail

P=0.716913 > 0.05

Therefore, H0 is accepted and HI is rejected

4.4 Fetal Thoracic Circumference Growth Rate

Geometric mean= 0.3874cm/week. The Growth rate at the second

trimester was 0.8169/week and third trimester 0.8217/week

4.5 Prediction of GA From TC

Predictive equation: y = 4.65 + 1.13(TC)

y = gestational age in weeks

x= thoracic circumference

74

TABLE 5: Predic5ted GA from equation 75th Percentile in Nigerians

GA = 4.65 + 1.13 TC S/N GA (WEEKS) TC

1 15 9.1590

2 16 10.044

3 17 10.929

4 18 11.814

5 19 12.699

6 20 13.584

7 21 14.469

8 22 15.354

9 23 16.239

10 24 17.124

11 25 18.009

12 26 18.894

13 27 19.779

14 28 20.664

15 29 21.549

16 30 22.434

17 31 23.319

18 32 24.204

19 33 25.088

20 34 25.973

21 35 26.858

22 36 27.743

23 37 28.628

24 38 29.513

25 39 30.398

26 40 31.283

27 41 32.168

The above table 4 shows the novel TC nomogram from the Nigerian

population

75

Fig.18: Scatter diagram of TC against BPD. There was a highly positive

correlation and statistically significant correlation is noted between the

TC and BPD (r2=0.9824, P � 0.001).

There is high strong correction between the TC and other biometric

parameters such as BPD, HC, AC and FL.

��

��

�

�

��

��

��

��

��

��

�

� � � � ��

$��"��% ��!��!��

&!��!��"�'!��

!"

��!"�

76

Fig.19: Scatter diagram of TC against HC. There was a highly positive


TC and HC (r2=0.9806, P � 0.001)

��

��

�

�

��

��

��

��

��

��

� ��

$��"��% ��!��!��

$��"�%��'��!��

!"

��!"�

77

Fig.20: Scatter diagram of TC against AC. There was a highly positive


TC and AC (r2=0.9712, P � 0.001).

��

��

�

�

��

��

��

��

��

��

�

� � ��

$��"��% ��!��!��

$��"��' � !��"��!��

!"

��!"�

78

Fig. 21: Scatter diagram of TC against FL. There is a highly positive


TC and FL (r2=0.9862, P � 0.001)

��

��

�

�

��

��

��

��

��

��

� � � � ��

$��"��% ��!��!��

$��"�� "��%�

#��

��#��

79

TABLE 6: Regression model for TC against BPD, FL, HC.

Using the formula Y = a+bx

S/N Y X A B R

Dependent Variable

Independent Variable

1 TC BPD 1.07 4.08 97.40%

2 TC FL 5.67 4.33 98.62%

3 TC HC 1.64 0.99 98.06%

Table 7: Gestational age groups and their coefficient of

determination

Gestational age group Coefficient of determination

15 – 23 0.8050

24 – 32 0.7832

33 – 41 0.7182

The gestational age group and their respective coefficient of

determination are presented in table above. The foetal GA 15-23 weeks is

more accurate (80.50%) than 24-32 and 33-41 weeks 78.32% and 71.32%

respectively in table 6.

80

4.6 Discussion

The study involved 907 pregnant women between the ages of 15 and 42

years and TC values range from 9.157-32.168cm within 15-41 weeks of

GA. The majority of the participants were women between 20-24 (87%)

years. The minimum age of 15 years shows that girls in the region marry

at a very young age (Fig.16). The minority were 40 years and above, this

because of climacteric period The tribe that dominated the study was the

kANURI (30.97%) because Kanuri is the major tribe in this locality,

followed by the Igbo’s (18.07%) because they are more enlighten and

seek health care. The Table 2 also shows the diverse ethnic groups in the

country even though it was just a few that were represented in the study.

This study showed that there was no significance difference in the TC of

population studied and that of the Caucasian population which is not in

line with the findings of Matrobattista et al (2004).

The study showed that there was a linear relationship between TC and the

weeks of gestation which is in line with the findings of Chitkara et

al(1987). Therefore, the values of the Caucasian population can be used

on locality studied population.

The majority of women scaned were between 30 and 40weeks pregnant

(fig 16). At this period of time, the foetus is well developed and has

already grown to some extend therefore making the accurate dating

81

difficult (Ohagwu et. al., 2009). According to Agwu et al. (2008),

optimal information is obtained when the scan is carried out between the

14th and the 18th week of gestation. Also, the second trimester pregnancy

scan is best performed at 18-20 weeks of pregnancy mainly to look for

congenital malformation, when the foetus is large enough for an accurate

survey of foetal anatomy, multiple pregnancies can be firmly diagnosed

and dates and growth can also be assessed(Ola-oja, 2005).

The data presented in Table 4 shows the normal values of the foetal

thoracic circumference which can be used to determine the gestational

age. The data analysis also shows that there is a strong correlation (r2=

0.974) between the fetal thoracic circumference and the gestational age .

This agrees with finding Chitkara et al.,(1987). They found that there was

a close correlation (r2 =0.94) between the fetal thoracic circumference and

the gestational age in normally growing fetuses. This therefore means

that the fetal thoracic circumference can be used reliably as a predictor of

the gestational age in the 2nd and 3rd trimester. Though several parameters

are used to determine the gestational age, fetal thoracic circumference can

be used when it is difficult to get the accurate view for the measurement

of other parameters. Also this can be added to them so as to have many

parameters used to determine the gestational age as it is important to find

new parameters to measure foetal growth that correlate with fetal age.

82

The fetal thoracic circumference grows linearly with the gestational age.

This is expressed by the line of best fit obtained using the method of least

square. This equation(Y= 4.65 + 1.13TC) can easily be used to determine

the gestational age. This was used in prediction of the gestational age

were table 4 of foetal thoracic circumference and gestational age is not

available.

The fetal thoracic circumference is more accurate in determining the

gestational age between 15 and 23 weeks of gestation and this accuracy

reduces as the pregnancy progresses. This agrees with finding who found

that the earlier the ultrasound assessment, the more accurate the

prediction of the date of delivery.

The average fetal thoracic circumference growth rate per week was

0.3874cm. This value should be used to assess normal foetal growth thus

any intra-uterine growth retriction (IUGR) and overgrowth can be

diagnosed. Most of the women scaned were between 30 and 40 weeks

pregnant. This the period at which the thoracic circumference is less

accurate (Ola-oja, 2005). This will therefore lead to less precise

gestational age prediction. It is necessary for the women to come for

prenatal ultrasound scan in early pregnancy so that an accurate prediction

of gestational age can be made.

83

CHAPTER FIVE

SUMMARY AND CONCLUSIONS,

5.0 Summary of Major Findings

Majority of the women coming for ultrasound scan were between 20 and

24 years old. Majority of the women scanned were between 30 and 40

weeks of GA, this is the period at which the fetal thoracic circumference

is less accurate in predicting the gestational age.

A nomogram is drawn to determine the gestational age based on the fetal

thoracic circumference. This normative value have no statistical

difference with Caucasian values. The thoracic circumference is more

accurate in determining the gestational age between the 15 and 23 weeks

of gestation and its accuracy decreases as the pregnancy progresses.

There is a strong linear correlation between the TC and the BPD, HC,AC

and FL with these values respectively (r2= 0.9740, P�0.001), (r2= 0.9824,

P�0.001),(r2= 0.9806, P�0.001), (r2= 0.9712, P�0.001), (r2= 0.9862,

P�0.001).

The equation for determining the gestational age based on foetal thoracic

circumference is Y= 4.65 + 1.13TC.

The accuracy of TC in predicting GA is 97.40% while those of BPD, HC,

AC and FL accuracy were 98.24%, 98.06%, 97.12% and 98.62%

respectively. There was no statistically significant differences between

84

TC and others (BPD, HC, AC, FL) established biometric parameters in

predicting GA. The average growth rate is Geometric mean=

0.3874cm/week.

5.1 Conclusion

There is a linear relationship between TC and the gestation age at a

growth rate of 0.3874cm per week. Statistically, there is no significant

difference between the TC of population studied and that of Caucasian

population even though they from different ethnic groups and race.Hence,

Caucasian nomogram can be used as TC dating model with this evidence

based study. The study has derived a nomogram of fetal thoracic

circumference in Nigerian population and shown that the fetal thoracic

circumference is a good predictor of gestational age especially in early

second trimester.

5.2 Recommendation Based on the Finding

The nomogram of thoracic circumference of fetus developed should be

used for more accurate dating of pregnancies sonographical, especially

thoracic sparing IUGR because it is more reliable and accurate in early

second trimester. Thoracic circumference model of dating should be used

due to ease of identifying landmarks for measurement using the four heart

chamber view.

85

5.3 Study’s Contributions to Knowledge

A Sonographic nomogram of fetal chest circumference prediction of GA

has been developed. Fetal chest growth rate of local population studied is

0.3875cm/week. The regression equation is y = 4.65 + 1.13TC, this can

be used to predict the GA when the TC chart is not available.

5.4 Areas of Further Studies

A study to derive normative thoracic ratio from thoracic circumference

and thoracic length and/or thoracic circumference and abdominal

circumference of local population as indicator of abnormal fetal growth

should be studied.

86

REFERENCES

ACR-ACOG-AIUM, (2007). Practice guideline for the performance of obstetrical ultrasound obstetrical ultrasound (Reg. 25)

AIUM, (2006). AIUM Practice Guideline for the performance of the

ultrasound examination of the female pelvis. AIUM Altman, D.G. and Chitty, L.S., (1997). New Charts for Ultrasound dating

of pregnancy Ultrasound Obstet Gynecol 10:174-191 Apfel and Green, P.C., (1999). What is fetal growth retardation? Medical

information. So what Montgomery Avenue, Suite 200 Rockville, Maryland 20850.

Agwu, K.,Chiegwu, H.U. and Nwobi, I.C.,(2008). 2D Sonographic

Assessment of the Fetal Liver in Normal Pregnant Nigeria Women.Journal of Diagnostic Medical Sonogrphy.Vol.24 No.6:361-364

Beigi, A., Zarrinkoub, F., (2000). Ultrasound assessment of fetal

biparietal diameter and femur length during normal pregnancy in Iranian women. International Gynecology-Obstetrics; 69 (3) 237-242

Benson, C.B. and Doubilet, P.M., (1991). Sonographic prediction of

Gestation Age: Accuracy of second and third trimester fetal measurements. AJR 1275-1277

Berghella, V., (2010). Every 30 second a baby dies of preterm birth.

What are doing about it? AJOG: 416-417 Campbell, S., Warsolf, S.L., Little, D., Cooper, D.J., (1985). Routine

ultrasound screening for the prediction of getational age. Obstet Gyenecol, 65:613-620

Chitkara, U., Rosenberg, J., Checanak, F.A., et. al., (1987). Prenatal

Sonographic Assessment of Thorax: Normal Values. Am J Obstetric Gynaecology 156:1069-1074.

Chuldleigh, T. and Thilaaganathan, B., Childleigh, P., (2004). Obstetric

ultrasound. How, why and when. 3rd ed. Toronto .Elsevier Churchill Livingstone.

87

Chudlwigh, P., Peace, M.J., (1986). Obstetric Ultrasound: How, Why and When.

Davidson, J.M., Lind, T., Farr, V., Whittingham, T.A.,(1981). The

Limitations of Ultrasonic Fetal Cephalometris. J Obset Gyroecol Br Commonus 80:769

De La Verga, A.,(1999). Patient-Physician Expectations and Reality in

Modern Obstetrics. Obstetrics and Gynaecology Today. University of Puerto Rica School of Medicine.

De La Verga, A., (2000). Sonographic evaluation of Gestational Age and

Fetal Weight. Obstetrics and Gynaecology Today. University of Puerto Rico, School of Medicine.

De La Verga, A.,(2002). Sonographic evaluation of gestational age and

fetal weight. Obstetrics and Gynaecology Today. University of Puerto Rica School of Medicine.

De La Vega, A., Ruiz-febo, N., Roberts, Z.C., (2008). Fetal ultrasound

biometry. Normative charts for a Puerto Rican population. OB/GYN section vol. 27 no. 1

De Vore,G.S.,Sarti, D.A.,Siassi, B. et al., (2009).Prenatal diagnosis of

cardiovascular malformation in the foetus with situs inversus viscerum during the second trimester of pregnancy J. Clin Ultrasound.

Doubilet, P.M., Greenes, R.A., (1984). Improved Prediction of

Gestational age from fetal Head Measurements. AJR 137:83 Dugoff, L., Coffin, C.T., Hobbins, J.C., (1996). Sonographic

Measurement of the fetal ribeage perimeter to thoracic Circumference ratio: application to prenatal diagnosis of skeletal dysplasias. European Journal of Ultrasound. 4(1): 21-26

Eze, C.U., Ezugwu, F.O. and Agbo, J.A., (2010). Sonographic

determination of fetal gender in the second and third trimester in a private hospital in Enugu, Southeast Nigeria. Radiography.16:292-296

88

Fong, K.,Ohlsson, A.,Zalev A.,(1988).Fetal thoracic circumference:a prospective cross sectional study with real-time ultrasound.Am J Obstet Gynecol.158(5) :1154-60.

GGaarrrreetttt,, WW..JJ..,, RRoobbiinnssoonn,, DD..EE..,,((11997711)) ..AAsssseessssmmeenntt ooff ffeettaall ssiizzee aanndd ggrroowwtthh

rraattee bbyy uullttrraassoonniicc eecchhoossccooppyy.. OObbsstteett GGyynneeccooll;; 3388::552255 Hadlock, F.P., Deter, R.L., Harrist, R.B., Part, S.K., (1982). Fetal Head

Circumference: Relation to Menstrual Age AJR 138:649 Hill, I.M., Guzick, D., Peterson. C., Dinofrio, D., Malone, J., Nedzeksy.

P., (1991). Fetal heart circumference as a predictor of the gestational age. AJR, 157,1275

Jensen, S.L., et. al.,(2004). Fetal age assessment on Sonogram head

biometry and effect of Maternal and Fetal factors. Acta Obstetricia and gynecologica scandiavka; 83 (2):716-718

Johnson, J.M., (2005). Overview of obstetric sonography in: C.M.

Rumack, S.R Wilson, Charboneau J.W., J.M. Johnson, eds. 2005. Diagnostic ultrasound 3rd ed. China Elsevier Mosby Ch. 30.

Konje, J.C., Abram, K.R., Bell, S.C., Taylo, D.J., (2002). Determination

of getational age after 24 weeks of gestation from fetal kidney length measurements Ultrasound Obstet Gynecol, 19(6):592-161.

Kuldeep, S. and Narenda, M., (2002). Step by step color Doppler in

obstetrics , Gynecoloy and infertility. New Delhi, Jaypee Brothers. Kugener, H., Hensman, M., (1976) .Zur Topographic einer referenzebene

fur die ultraschalthorako-metrie. J Clin ultrasound 6:409. Mastrobattista, J.M., Pschirrer, E.R., Hamrick, M.A., et.al (2004).

Humeral length evaluation in different ethinic groups. Journal of ultrasound in Medicine, 23:227-231

Mayden, K., Tortora, M., Berkowitz R, et. al., (1982). Orbital diameters:

A new parameter for prenatal diagnosis and dating. Am j Obstet Gynecol 144:3, 289-297

Mclennan, A.C. and Schluter,P.J., (2008). Construction of modern

Australian first trimester ultrasound dating and growth charts. Journal of medical imaging and radiation oncology. 52:471-479

89

Mercer, B.M., (1987). Foetal foot length as a predictor of foetel age. Amj Gynecol, 156(2)350-355

Mercer, B.M., (1987). Foetal foot length as a predictor of foetel age. Amj

Gynecol, 156(2)350-355 Mongelli, M. and Gardosi, J., (2008). Evaluation of gestation. E-medicine MMoooorree,, KK.. LL.. aanndd PPeerrssaauudd,, TT..VV..NN..,,((22000033)).. TThhee DDeevveellooppiinngg HHuummaann;;

cclliinniiccaallllyy oorriieenntteedd eemmbbrryyoollooggyy.. 77tthh eedd.. ;; 119999 Nahid, Y., Moslem, F., Haque, A.J., (2007).Fetal kidney length: Can be a

new parameter for determining the gestational age in third trimester. Journal of teachers association, 20(2): 147-150.

Ogunsina, J.A, Soyebi, K.O., Ogunseyinde, A.O.,et. al., (2001). Multiple

Foetal. Parameters in the Estimation of Gestational Age in Nigerian Pregnant Women. West African Journal of Ultrasound. 2:17-21.

Ohagwu, C.C. Abu, P.O., Udoh, B.E., (2009). A sonographic indicator of

gestational age in normal singleton pregnancies in Nigerian women. Internet journal of Medical update.4(2):9-14.

Ola-Oja, O. O. (2005). Obstetric and gynaecology ultrasound- a self

Assessment Guidance’ London: Elsevier Churchil Living stone. �

Parikh R. M. (2007). "Parikh’s formula to minimize errors in calculating expected Date of Delivery". Medical Hypotheses 68 (4): 928. .

Pekka,T. and Vilho, H., (2001). Predicting Delivery Date by Ultrasound

and last Menstrual Period in early gestation. Obstetrics and Gynaecology. 97:189-194.

Rajiakshmi, C.H., Shyam, S.M., Bidhumukhi, D.T. and Chandramani,

S.L., (2001). Cephalic Index of Foetuses of Manipuri Population – A Baseline Study. Journal of the Anatomical Society of India. 50(1):8-10.

Requejo, J.H. and Materials, M., (2010). The global impact of pretem

birth In: Berghella V. Ed preterm birth: Prevention and management oxford, UK: Wiley-Blackwell 1-7.

90

Ruwack, C.M., Wilson, S.R., Charboneau, J.W. et al.,(eds.), (2005).Diagnostic Ultrasound, Volume 2,( 3rd ed.).China.Elsevier MOSBY.

Sander, R., (1998). Clinical sonography: a practice guide, 3rd edition. Pp

79, 183-206 Sanders, R.C. and winter, T., (2004). Clinical sonography. A practical

guide 4th edition philiphedia. Lippincott Williams and Wilkins Sherer, D.M., Sokolovski, M., Dailoul, M., et. al., (2007). Nomograms of

the fetal neck circumference and area throughout gestation, 26(11):1529-37

Singh, I. and Pal, G.P., (2001). Human Embryology 7th ed; 124-130, 211-

266. Shepard, M., Filly, R.A., (1982). A Standardized plane for biparietal

diameter measurement J. Ultrasound Med. 1:145. SSuubbbbaarraaoo,, KK..,, BBaanneerrjjeeee,, SS..,, AAggggaarrwwaall,, SS..KK.. eett aall..,, ((eeddss))((22000033)).. DDiiaaggnnoossttiicc

RRaaddiioollooggyy aanndd IImmaaggiinngg.. 884477--6611.. UUggwwuu,, AA..CC..,, EEwwuunnoonnuu,, EE..OO..,, NNwwoobbii,, II..CC..,, eett.. aall..,,((22000077))..SSoonnooggrraapphhiicc

aasssseessssmmeenntt ooff ffooeettaall cceepphhaalliicc iinnddeexx iinn aa NNiiggeerriiaann ppooppuullaattiioonn:: AA nnoovveell ppaarraaddiiggmm.. JJoouurrnnaall ooff MMeeddiiccaall DDiiaaggnnoossttiicc SSoonnooggrraapphhyy.. 2233 ((33)):: 8877--9900..

Ugwu, A.C., Nwobi, I.C., Eteude, A.N.et al., (2008). The effect of

Normocephelic foetal Skull of Foetal Dating using Biparietal Diameter. OJHAS vol.7 (2):5.

Ulm, M.R., Kratochmil, A., Oberhuemer, U.et al., (1999) Ultrasound

evaluation of the fetal spine between 14 and 24 weeks of gestation. Prenatal diagnostic, 19(7):637-64.

Westerway, S.C., Davison, A., Cowell, S., (2002). Ultrasonic fetal

measurements, New Australian standards for the new millennium.. Br J. Obstet Gynaecol; 109:919.

WOO, J., (2001). A short history of the development of ultrasound in

obstetrics and gynaecology. Available at http://www.ob.ultrasoundac_historical.html.

91

Yusuf, N., Moslem, F., Naque, J., (2007).Fetal Kidney length as a predictor of gestational age. Journey of Teachers Association, Rajshahi ; 20:1017-1018

Zegers-Hochschild, F., Nygrenk, G., Adamson, G., et. al., (2006). The

ICMART glossary on ART terminology. Human reproduction Vol. 21, No. 8 pp. 1968-1970

92

APPENDIX I

93

APPENDIX II

PARTICIPANT CONSENT FORM

RESEARCH TITLE: SONOGRAPHIC ASSESSMENT OF FOETAL

THORACIC CIRCUMFERENCE AS A PREDICTOR OF

GESTATIONAL AGE IN A NIGERIAN POPULATION

1. BACKGROUND INFORMATION

This is a request form to consent to be participant in a study titled:

Sonographic Assessment of Foetal Thoracic Circumference as a Predictor

of Gestational Age in a Nigerian Population.

The research finding generated by this study will aid in best estimate of

gestational age (GA) of pregnant women from the second and third

trimester.

The research finding will be valuable to health care practitioner’s in

predicting more accurate GA and Foetus at risk, thus prompt and better

management of women at risk by doctors.

2. VOLUNTARY NATURE OF THE STUDY

The participation is voluntary in nature. You have the right to refuse

participation and/or withdraw at any point during the study. This decision

will not affect your current and future relationship with the hospital.

3. STUDY RISK

There is no evidence that ultrasound scan posses risk to the foetus and/or

the mother. It is a reliable imaging modality for assessing foetal GA.

94

4. COST ADDITION

There is no financial cost to you for consenting to participate in this

study. As a participant, the study will be part of your normal obstetric

scan which you have already paid for prior to the scan.

5. CONFIDENTIALITY

Your identity will not be included and revealed as part of the study

gathering and it is impossible to identify you in any way after gathering

the data. The records are private. All information obtained will be

handled with strick confidentiality.

6. FEEDBACK

My name is Nwobi Chigozie, the researcher, I can be contacted through

the GSM no. 08034545811 or my Supervisor, Prof. K.K. Agwu via

07089585847

7. STATEMENT OF CONSENTS

I agreed that I have read and understood the content of the consent form

(or some one read and explained the study in my local language: Hausa,

Kanuri, e.t.c.). I am aware of the nature and benefit of this study and my

questions have been answered to my satisfaction .Hence, I hereby give

my consent to be a participant to this study.

....................................................... ……………………. Signature of participant/ thumb print Date ....................................................... ……………………. If applicable, Interpreter’s signature Date

....................................................... ……………………. Signature of researcher Date

95

APPENDIX III

Table 8: Mean values of BPD, FL, HC and TC with GA

S/N Number of measurements

(weeks) G.A

BPD (cm)

FL (cm)

HC (cm)

TC (cm)

1 16 15 15.000 1.9500 12.400 7.9357 2 13 16 21.00 2.154 14.28 8.812 3 24 17 17.000 2.3667 14.467 9.795 4 24 18 17.000 2.7583 15.750 12.310 5 14 19 18.000 2.9286 17.457 12.863 6 32 20 18.562 3.4438 17.556 14.054 7 45 21 19.378 3.6422 19.729 15.330 8 62 22 20.823 3.8177 20.956 15.342 9 26 23 24.346 4.331 23.396 16.857 10 39 24 22.872 4.4667 23.787 18.212 11 59 25 23.390 4.6017 24.039 18.508 12 41 26 23.537 4.9000 25.007 18.589 13 44 27 26.091 4.9227 26.595 20.964 14 22 28 27.364 5.2273 27.127 20.971 15 48 29 27.092 5.8158 28.717 22.327 16 32 30 27.231 5.8125 29.181 23.336 17 22 31 28.091 5.9364 30.391 24.871 18 11 32 29.909 6.109 31.173 25.771 19 18 33 30.033 6.2444 31.256 25.929 20 52 34 30.377 6.6058 32.919 26.104 21 72 35 33.053 6.8056 34.326 26.891 22 48 36 33.192 6.948 35.21 26.924 23 65 37 33.215 7.1062 35.943 27.137 24 31 38 33.313 7.2000 35.990 27.160 25 14 39 33.571 7.4000 36.286 27.410 26 16 40 40.000 7.8500 37.200 31.271 27 17 41 41.000 8.0529 38.406 32.381

96

APPENDIX IV

Table 9: Comparison of mean values of TC and HC against GA

S/N G.A (WEEKS) MEAN TC (cm) S.D MEAN H.C S.D. 1 15 7.9357 0.2434 12.400 0.103 2 16 8.812 0.398 14.28 8.66 3 17 9.795 1.091 14.467 0.255 4 18 12.310 0.785 15.750 0.465 5 19 12.863 0.726 17.457 0.051 6 20 14.054 1.798 17.556 0.559 7 21 15.330 1.455 19.729 0.624 8 22 15.342 1.249 20.956 0.497 9 23 16.857 0.293 23.396 4.837 10 24 18.212 1.942 23.787 1.868 11 25 18.508 0.961 24.039 0.533 12 26 18.589 0.950 25.007 0.729 13 27 20.964 1.190 26.595 1.474 14 28 20.971 1.664 27.127 0.554 15 29 22.327 1.254 28.717 0.519 16 30 23.336 1.080 29.181 0.263 17 31 24.871 2.468 30.391 0.252 18 32 25.771 0.903 31.173 1.462 19 33 25.929 0.000 31.256 0.051 20 34 26.104 0.926 32.919 0.510 21 35 26.891 1.811 34.326 1.508 22 36 26.924 1.006 35.21 7.11 23 37 27.137 2.224 35.943 3.386 24 38 27.160 0.846 35.990 0.432 25 39 27.410 2.179 36.286 0.616 26 40 31.271 0.162 37.200 0.103 27 41 32.381 0.162 38.406 0.103

97

APPENDIX V

Fig. 22: Sonogram of foetal thoracic circumference. Source

Manjuganesh

98

AAPPPPEENNDDIIXX VVII

DDAATTAA CCAAPPTTUURREE SSHHEEEETT

S/NO AGE TRIBE PARITY TC D1

TC D2

B̀PD BPD GA

AC FL HC LMP AGA

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

99

22

23

24

25

26

27

28

29

30

31

32

33

34

35

KKEEYY:: TTCC == TThhoorraacciicc cciirrccuummffeerreennccee,, BBPPDD == BBiippaarriieettaall ddiiaammeetteerr,, HHCC == HHeeaadd

cciirrccuummffeerreennccee,, AACC == AAbbddoommiinnaall cciirrccuummffeerreennccee,, FFLL == FFeemmuurr lleennggtthh,, LLMMPP == LLaasstt

mmeennssttrruuaall ppeerriioodd,, AAGGAA == AAvveerraaggee ggeessttaattiioonnaall aaggee..

100

AAPPPPEENNDDIIXX VVIIII

RRAAWW DDAATTAA SSHHEEEETT

S/N

1

AGE

2

TRIBE

3

PARITY

4

BPD

8

BPD

GA

9

AC

10

FL

11

HC

12

LMP

13

Average

GA

14

5

D1

6

D2

7

TC

1 28 1 7.2 6.9 21.4 7.3 24w4d 23.8 5.3 28.1 6/2/8 24wks

2 29 Marghi 3 6.9 6.0 19.6 7.0 26w5d 23.6 5.2 28.5 2w2ds

3 30 Ibo 4 8.3 9.9 27.6 8.6 33w3d 31.3 7.4 34.6 13/12/07 38w6d

4 20 Mandara 4 3.7 3.3 10.6 3.8 17w 11.4 2.5 15.1 17w5d

5 22 Kanuri 1 5.6 6.4 18.2 5.7 22w3d 20.6 4.8 24.3 26w3d

6 18 Labda 1 6.4 5.3 17.7 5.5 21w5d 19.0 4.7 24.0 25w4d

7 30 Ibo 2 4.0 4.3 12.6 4.3 18w1d 14.3 3.1 16.9 19/4/08 19w5d

8 25 Hausa 3 6.8 6.3 19.9 7.2 27w1d 23.1 5.3 28.0 15/2/08 28w4d

9 22 Igala 1 7.4 6.5 13.9 7.1 27w 24.8 5.9 30.1 31w2d

10 21 Hausa 1 5.0 4.6 14.5 5.1 20w5d 16.1 3.5 19.7 21w4d

11 20 Kanuri 0 6.8 6.9 20.8 7.0 26w4d 24.8 5.5 28.9 30w2d

12 40 Kilba 2 11.4 9.8 32.2 9.2 35w4d 39.4 8.2 36.5 11/12/07 Out of r.

13 20 Marghi 0 8.5 10.3 28.5 8.7 33w3d 29.6 7.0 34.9 37w7d

14 18 Kanuri 1 7.2 5.9 19.9 6.7 26w4d 22.3 5.0 25.6 37w2d

15 22 Hausa 0 5.3 5.6 16.5 5.4 23w4d 19.3 4.4 21.8 16/3/08 23w5d

16 32 Kanuri 5 4.9 4.5 14.2 4.9 20w1d 15.9 3.6 19.8 23/4/08 21w4d

17 29 Igbo 2 5.6 5.7 17.1 5.3 21w2d 17.9 3.8 21.2 22w6d

18 24 Fulani 0 6.1 5.7 17.9 6.1 22w4d 19.3 4.8 24.3 07/3/08 26w

19 32

32

Fulani

Fulani

9

9

7.1

7.6

8.2

8.3

23.2

24.1

8.0

7.7

30w

29w

27.3

25.5

6.4

6.1

32.8

31.6

29/12/07

29/12/07

34w1d

32w3d

20 30 Igala 6 4.0 4.7 13.2 4.2 18w 14.6 3.1 17.4 27/4/07 19w5d

21 17 Fulani 0 5.2 4.6 14.8 5.0 20w3d 16.2 4.1 21.1 22w3d

22 20 Fulani 0 5.1 4.7 14.8 5.2 21w0d 15.9 3.6 20.8 20/4/08 21w3d

101

23 25 Igbo 0 8.0 7.9 24.1 9.0 34w3d 32.0 6.6 36.7 27/12/07 36w2d

24 24 Kanuri 0 9.4 8.2 26.7 8.6 32w2d 31.7 7.1 34.8 371d

25 38 Kanuri 8 5.1 5.4 15.9 5.6 22w5d 16.2 3.8 22.0 28/7/08 22w3d

26 27 Shuwa 0 8.0 8.6 25.2 8.5 32wks 28.0 6.7 34.6 2/2/08 36w3d

27 25 Kanuri 0 7.5 9.0 25.0 8.3 31w2d 28.4 6.5 32.8 34w5d

28 29 Kanuri 4 6.2 5.6 17.9 5.8 22w5d 19.5 4.4 22.7 24w4d

29 26 Kanuri 2 8.3 8.0 24.7 9.0 34w2d 27.7 6.8 33.4 24/1/08 35w0d

30 20 Kanuri 0 9.5 9.2 28.4 8.0 29w6d 30.0 7.0 32.6 36w1d

31 38 Shuwa 6 9.4 9.4 28.5 8.7 33w1d 31.0 7.3 34.8 1/1/08 38w5d

32 30 Babur 7 8.3 7.6 24.1 8.5 32w2d 29.1 6.7 33.6 20/12/07 39w0d

33 27 Kilba 0 10 10.6 31.3 8.8 33w4d 31.8 7.3 36.5 24/12/07 35w0d

34 34 Glabda 6 9.8 8.0 27.0 8.6 32w2d 29.8 7.7 35.1 2/2/08 35w2d

35 34 Igbo 2 8.7 8.3 25,8 8.4 31w5d 33.4 7.0 34.4 01/8/08 32w6d

36 46 Mandara 11 9.1 8.2 26.2 7.9 29w5d 29.2 6.3 32.0 01/6/08 16w0d

37 29 Kanuri 5 3.0 3.3 9.5 3.2 15w0d 9.7 2.6 13.0 36w2dt3

38 30 Kanuri 5 8.8 7.4 24.6 8.7 33w1d 27.9 6.9 34.1 23w5d

39 35 Karekere 4 5.4 5.0 15.2 5.7 22w3d 17.6 4.3 21.8 3/3/08 23w5d

40 30 Kanuri 6 7.1 6.6 20.8 6.8 26w 22.0 4.6 29.9 27wks

41 31 Marghi 3 10.8 9.1 30.2 9.2 35w+3 34.3 7.3 37.0 11/1/8 36w+4d

42 38 Marghi 2 9.3 8.0 26.2 9.0 34w+5d 28.5 6.9 34.1 7/2/8 35w+6d

43 28 Kanuri 0 7.6 5.4 19.7 7.0 26w+4d 22.8 6.7 28.4 11/3/8 29w+0d

44 27 Kanuri 0 7.1 5.5 19.1 6.3 24w+3d 20.9 5.1 26.2 31/3/8 26w+5d

S/N

1

AGE

2

TRIBE

3

PARIT

Y

4

BPD

8

BPD

GA

9

AC

10

FL

11

HC

12

LMP

13

Average

GA

14

5

D1

6

D2

7

TC

45 22 Kanuri 2 6.8 6.3 19.9 6.6 25w+3 22.5 5.0 27.6 28w+2d

46 33 Kanuri 6 7.1 6.9 21.2 7.5 28w+1d 23.1 5.8 28.7 29w+4d

47 29 Shuwa 0 6.0 6.3 18.6 6.3 24w+2d 20.5 4.2 24.2 16/4/8 25w+2d

48 23 Kanuri 0 8.6 9.8 27.9 8.9 34weks 31.4 35.6 30/1/8 38weeks

102

49 28 Kanuri 2 8.9 8.4 26.2 8.2 30w+6d 31.3 7.1 37.5 14/4/8 37w+1d

50 36 Igbo 6 8.3 7.9 24.6 8.4 31w+5d 31.3 6.9 33.5 2/2/8 34w+5d

51 20 Kanuri 0 8.9 8.0 25.6 7.9 29w+5d 27.6 6.4 33.4 2/2/8 34w+4d

52 40 Marghi 6 7.0 7.4 21.8 6.7 25w+5d 22.0 4.9 26.6 27w+1d

53 27 Marghi 0 4.6 4.8 14.2 4.7 19w+2d 14.6 3.4 18.2 20w+4d

54 23 Kanuri 0 6.1 7.0 13.1 6.8 26w+0d 21.9 5.2 27.1 7/4/8 27w+5d

55 40 Kanuri 5 7.1 7.1 21.5 7.4 28weks 23.9 5.8 29.6 7/3/8 29w+6d

56 37 Chibok 2 8.1 8.3 24.9 7.7 29weks 26.7 6.2 31.3 3/8 33weeks

57 15 Fulani 0 10.4 9.5 30.2 9.1 35w+0d 33.1 7.8 36.2 35weeks

58 35 Kanuri 7 7.7 6.9 22.1 6.6 25w+2d 22.8 5.6 28.1 13/4/8 29w+3d

59 24 Fulani 4 5.4 5.3 16.2 5.7 22w+2d 18.2 3.8 22.4 22/5/8 23w+3d

60 18 Hausa 0 9.0 10.2 29.1 8.1 30w+4d 29.5 6.9 32.5 35w+5d

61 31 Kanuri 3 5.8 5.4 15.6 5.0 20w+3d 16.6 3.6 20.2 25/5/8 21w+6d

62 19 Kanuri 0 4.9 5.9 17.7 5.7 22w+3d 18.6 4.1 23.1 24w+0d

63 26 Kanuri 2 9.4 10.3 29.9 8.5 32weks 30.3 7.0 34.6 6/2/8 37w+4d

64 25 Fulani 2 4.1 4.1 12.4 3.9 17w+2d 12.7 2.8 15.7 18w+3d

65 21 Fulani 0 9.5 7.8 26.2 8.7 33w+1d 30.4 7.1 34.9 28/1/8 37w+3d

66 19 Shuwa 0 5.3 4.5 14.8 5.1 20w+4d 16.9 3.8 21.4 22w+3d

67 26 Igbo 3 5.8 5.9 17.7 6.2 24w+3d 20.1 4.7 24.1 25w+3d

68 28 Kanuri 2 6.0 5.8 17.9 6.1 23w+4d 20.2 4.9 24.7 26w+4d

69 29 Shuwa 7 9.4 7.7 25.9 7.9 29w+4d 28.7 6.7 32.1 12/2/8 34w+3d

70 20 Hausa 0 9.2 8.4 26.7 8.8 33w+3d 29.2 6.9 35.2 26/3/8 36w+3d

71 20 Chibok 1 8.1 8.5 25.2 8.3 31w+3d 26.9 6.6 32.9 15/2/8 34w+3d

72 26 Shuwa 4 8.9 8.1 25.8 9.0 34w+3d 31.6 7.0 34.7 38w+1d

73 26 Kanuri 2 8.8 9.8 28.2 8.7 33w+1d 31.6 7.4 34.8 39w+2d

74 20 Kanuri 0 5.2 5.2 15.8 4.4 18w+4d 15.9 3.5 17.8 20w+5d

75 25 Kanuri 6 2.7 2.5 7.9 3.2 15week 9.6 1.9 12.5 15w+5d

103

76 27 Hausa 3 6.0 6.0 18.2 5.8 22w+4d 19.2 4.3 23.6 24/5/8 25w+1d

77 23 Babur 0 5.1 4.8 15.0 4.5 18w+5d 16.2 3.8 18.9 21w+2d

78 20 Hausa 4 3.7 3.2 10.4 3.6 16w+3d 11.6 2.3 14.6 17w+2d

79 30 Igbo 1 9.2 8.5 26.9 7.4 28w+1d 26.1 6.0 30.3 18/3/8 31w+0d

80 22 Kanuri 2 5.0 4.4 14.2 5.0 20w+3d 16.6 3.7 20.6 22w+0d

81 20 Kanuri 0 6.4 5.5 18.0 6.3 24w+1d 19.6 4.8 25.1 25w+5d

82 23 Babur 0 9.2 8.5 26.9 9.3 35w+5d 31.8 7.1 36.2 4/3/8 37w+3d

83 36 Fulani 4 3.9 3.9 11.8 4.5 18w4d 13.3 2.8 17.5 5/7/8 19w+3d

84 16 Kanuri 1 5.8 5.3 16.8 5.7 22w+2d 20.2 4.9 23.2 25w+1d

85 25 Kanuri 0 8.0 6.7 22.3 7.0 26w+4d 24.0 5.9 28.9 30w+4d

86 18 Fulani 0 7.7 7.7 23.4 7.8 29w+2d 25.2 5.9 30.7 31w+1d

87 25 Babur 3 6.1 5.5 17.6 5.0 20w+3d 17.9 4.3 21.3 24weks

104

S/N

1

AGE

2

TRIBE

3

PARITY

4

BPD

8

BPD

GA

9

AC

10

FL

11

HC

12

LMP

13

Averag

e

GA

14

5

D1

6

D2

7

TC

88 24 Babur 0 5.0 5.3 15.6 5.3 21w+1d 16.3 3.9 20.5 17/6/8 22w+2d

89 29 Fulani 0 8.4 7.3 23.8 7.5 28w+2d 25.0 5.6 29.3 28/4/8 30w+1d

90 35 Shuwa 4 10.3 10.3 31.3 9.1 35w+1d 33.6 7.7 35.8 20/2/8 35w+1d

91 35 Igbo 5 6.0 5.8 17.9 5.7 22w+2d 19.0 4.6 23.1 24w+4d

92 35 Wuruk 5 7.7 7.2 22.6 7.3 27w+4d 25.5 5.8 29.5 30w+2d

93 25 Igbo 0 4.0 4.5 12.9 4.4 18w+3d 16.5 3.7 19.2 21w+2d

94 31 Bura 3 10.3 10.4 31.4 10.0 41w+3d 38.1 8.1 38.5 10/2/8 41w+3d

95 29 Kanuri 1 7.7 7.8 23.5 7.2 27w+2d 24.8 5.5 28.8 29w+4d

96 35 Hausa 4 4.0 4.0 12.1 4.1 17w+5d 12.4 2.9 16.3 18w+5d

97 28 Marghi 1 8.8 8.3 25.9 8.2 30w+6d 28.6 6.7 32.4 35w+0d

98 30 Kanuri 5 2.4 3.8 9.4 3.7 16weks 11.5 2.0 14.9 16wks

99 17 Bajizim 0 2.6 2.7 8.0 3.7 17w+2d 12.3 2.2 14 17w+1d

100 30 Igbo 3 2.9 3.6 9.8 3.9 18weks 12.1 2.6 14.2 17w+3d

101 30 Hausa 3 3.5 3.9 11.2 4.6 19weks 14 2.9 17 20wks

102 27 Marghi 2 4 5 13.6 5.5 21w+5d 15.9 3.7 20.4 22w+3d

103 18 Kilba 0 3.5 4 11.4 5.7 22w+3d 15.8 3.8 20.7 22w+3

104 25 Kanuri 0 4.7 5.6 14.7 6.2 24weks 17.9 4.2 23 24w+3d

105 20 Igbo 0 5.6 5.0 17.0 6.5 25w+5d 18.4 4.7 24 25w+5

106 20 Bura 0 4.6 6.2 16.4 6.8 26w+6d 17.4 4.8 25 26w+6d

107 30 Fulani 2 5.9 6.3 18.5 7.1 27weks 19.7 4.8 25.9 27w+3d

108 25 Kanuri 2 4.7 6.3 16.7 7.2 27w+3d 20.6 5.2 26.7 28w+1d

109 28 Shuwa 7 6.0 8.3 21.7 7.3 28w+0d 20.7 5.2 26.9 28w+1d

110 20 Kanuri 3 7.4 6.8 21.5 9.2 35w+5d 26.4 6.2 33.4 35w+3d

105

111 20 Kanuri 4 6.9 7.5 21.8 8.4 34w+4d 26.7 7.3 30 37wks

112 18 Hausa 0`̀ 5.0 4.8 15.3 5.3 22w+1 17.1 4.0 22wk+2

d

113 45 Hausa 10 8.8 8.1 26.5 8.8 35w+4 32.5 7.2 36w+4d

114 32 Hausa 5 7.7 7.3 23.55 8.1 32w+4 27.1 7.8 32w+2d

115 18 Hausa 0 4.3 3.8 12.7 3.9 17w+6 13.8 2.4 17w+6d

116 Hausa 1 6.5 6.1 19.7 7.4 29w+5 24.0 5.5 29w+2d

117 20 Hausa 1 7.9 7.2 23.7 7.6 30w+4 24.1 6.3

118 20 Hausa 0 7.1 6.8 22.4 7.1 28w+4 23.8 5.7 28w+6d

119 25 Hausa 3 7.5 7.4 23.3 8.2 33w+0 28.4 6.5 33w+0d

120 20 Hausa 2 7.5 8.2 24.6 8.5 34w+5 30.4 6.5 34w+1d

121 25 Hausa 4 4.4 4.7 14.2 5.0 21w+1 16.3 3.1 20w+4d

122 20 Hausa 0 5.0 4.5 14.9 5.5 22w+6 18.1 4.0 22w+5d

123 20 Hausa 1 8.8 7.1 24.9 8.6 34w+5 29.6 7.0 34w+5d

124 20 Hausa 3 7.4 7.0 22.6 7.9 31w+5 27.4 6.5 32w+1d

125 20 Hausa 2 6.2 6.3 19.6 7.3 29w+3 23.8 5.7 29w+0d

126 22 Hausa 3 5.2 4.6 15.3 4.8 20w+4 19.0 3.5 21w+5d

127 23 Hausa 1 8.2 7.6 24.8 8.2 33w+0 26.9 6.3 32w+1d

128 24 Hausa 2 5.5 4.6 15.8 5.3 22w+1 18.6 4.1 22w+6d

129 26 Hausa 0 7.9 7.2 23.7 8.2 33w+0 27.1 5.8 32w+0d

130 26 Hausa 1 8.5 7.9 30.4 8.8 35w+4 31.0 7.3 36w+0d

The raw data of 130 of 907 participants.

106



BY

NWOBI, CHIGOZIE IVOR PG/M.Sc/03/37246

DEPARTMENT OF MEDICAL RADIOGRAPHY AND RADIOLOGICAL SCIENCES

FACULTY OF HEALTH SCIENCES AND TECHNOLOGY COLLEGE MEDICINE


FEBRUARY, 2012.

Documents

NWOBI, CHIGOZIE IVOR - University of Nigeria, Nsukka CHIGOZIE IVOR.pdf · Nwobi, Chigozie Ivor PG/M.Sc/03/37246 A D is er ta on Subm d h Department of Medical Radiography and Radiological