1st TRIMESTER PREGNANCY FAILURE

Shortened to emphasize medical student

curriculum requirementsCarlos M. Fernandez, M.D

Department of Obstetrics and Gynecology

Advocate Illinois Masonic and Medical Center

ULTRASOUND DIAGNOSIS OF INTRAUTERINE PREGNANCY

Diagnosis of IUP

“Double decidual sign” at 4½ to 5 wks

Gestational sac + yolk sac at 5 wks (a definitive sign of IUP)

GS + yolk sac + embryo at 5½ to 6 wks

CRL >5 mm – fetal cardiac activity presentSeeber BE and Barnhart KT. Obstet Gynecol

2006;107:339-413

First sign of IUP: double decidual sign

Earliest finding is the “double decidual sign” (arrows)

seen around 4½-5 wks gestation

initially eccentric in location

It excludes pseudogestational sac (free fluid or blood within endometrium)

Gestational Sac (confirmed by double

decidual sign) Grows 1 mm per day Usually seen by 4 ½ to 5 weeks of

gestation Discriminatory ß-hCG with TVS: usually

quoted 1000 - 2000 ß-hCG IU/L. Depends upon: Skill of the sonographer and image

magnification Frequency (5-10mHz) and resolution of

the transducer Uterine abnormalities, fibroids Multiple gestation

Gestational Sac

Discriminatory ß-hCG with TVS : 1000 - 2000 ß-hCG IU/L

Discriminatory ß-hCG with TAS: ≥ 6500 ß-hCG IU/L

Bhatt & Dogra, Radiol Clin N Am 45 (2007) 549-560

Long axis Short axis

The gestational sac diameter is used to

calculate gestational age

Second sign of IUP: Yolk Sac

First structure visualized within the gestational sac

Round , bright ring <6mm

A definitive sign of IUP Involutes after 11 weeks Can be seen half a week

before normal embryo is seen

When enlarged (“hydropic”), solid or duplicated, it is a very poor prognosis sign

Third sign of IUP: GS + yolk sac + embryo

GS + yolk sac + fetal pole at 5½ to 6 wks

The fetal pole (arrow) is better seen on the zoomed in image

GS grows 1mm/day

Embryo grows 1mm/day

Fourth sign of IUP: GS + YS + embryo + cardiac activity

Double decidual sign +yolk sac+ fetal pole +cardiac activity

Cardiac activity confirms a live intrauterine pregnancy

Cardiac activity is usually detected at 5 ½ to 6 weeks from last menstrual period

CRL ≥5 mm – fetal cardiac activity present

BHCG AND PROGESTERONE IN EARLY PREGNANCY

Serum concentrations of ß-hCG in 443 normal pregnancies

Braunstein G D, et al. Am J Obstet Gynecol 1976; 126:678-81.

ß-hCG is first detected in maternal serum 6 to 9 days after conception. The levels rise in a logarithmic fashion, peaking 8 to 10 weeks after the last menstrual period, followed by a decline to a nadir at 18 weeks, with subsequent levels remaining constant until delivery Second International Standard ß-hCG

Serial ß-hCG The doubling time for a normal

IUP is 2 days, with a range of 1.4 to 2.1 days

Doubling of ß-hCG is less reliable after 10,000 mIU/ml , at this level pregnancy is better evaluated with U/S

15% of normal IUP can demonstrate an abnormal rise of ß-hCG Kadar N, et al. Obstet Gynecol 1981;52:162-6

ß-hCG up to 10000 mIU/ml

The minimal rise in ß-hCG for a viable pregnancy is 53% in 48 hours

The minimal decline of a spontaneous abortion is 21-35% in 48 hours

A rise or fall in serial ß-hCG values that is slower than this is suggestive of an ectopic pregnancy

Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413

Hypothetical illustration of the rise, or fall, of serial hCG values in

women with an EP

Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413

53%

21-35%

SPONTANEOUS ABORTION: BACKGROUND, ETIOLOGY

Spontaneous abortion or miscarriage

Spontaneous abortion is a fetal loss before week 20 of pregnancy

Early loss is before menstrual week 12

Late loss refers to losses from weeks 12 to 20

80% of miscarriages occurring in the first trimester

Ferri: Ferri's Clinical Advisor 2012, 1st ed.

Miscarriage Miscarriage is the most common serious

pregnancy complication affecting approximately 30% of biochemical pregnancies and 11–20% of clinically recognized pregnancies

The diagnosis of miscarriage is made most commonly by trans-vaginal ultrasound (TVS) assessment

After a diagnosis of miscarriage, half the women undergo significant psychological effects, which may last for up to 12 months

Cecilia Bottomley, Tom Bourne. Diagnosing miscarriage. Best Practice & Research Clinical Obstetrics & Gynecology 2009; 23:463-77

Miscarriage The crucial role of chromosomal

imbalance in abnormal early human development is well established

Approximately 50–60% of first-trimester spontaneous abortions have karyotype abnormalities

Igor N Lebedev, Nadezhda V Ostroverkhova, Tatyana V Nikitina, Natalia N Sukhanova and Sergey A Nazarenko. Features of chromosomal abnormalities in spontaneous abortion cell culture failures detected by interphase FISH analysis. European Journal of Human Genetics 2004; 12:513–20

Miscarriage The most frequent type of

chromosomal abnormalities detected are:1. Autosomal trisomies ─ 52 %2. Monosomy X ─ 19 %3. Polyploidies ─ 22 %4. Other ─ 7 %

Hsu, LYF. Prenatal diagnosis of chromosomal abnormalities through amniocentesis. In: Genetic Disorders and the Fetus, 4th ed, Milunsky, A (Ed), The Johns Hopkins University Press, Baltimore 1998. p.179

CLASSIFICATION OF MISCARRIAGE

Clinical classification of spontaneous abortion

Type Definition

Threatened abortion

Vaginal bleeding during the first 20 weeks of pregnancy and no evidence of cervical dilation <50% of threatened abortions will progress to loss of pregnancy

Missed abortion Intrauterine demise of the conceptus without either vaginal bleeding or expulsion of the products of conception

Incomplete abortion

Vaginal bleeding with dilation of the cervix and partial expulsion of the conceptus

Complete abortion

Vaginal bleeding with expulsion of all of the products of conception

Inevitable abortion

Abortion in progress in which the bleeding is profuse with cervical dilation but a maintained intrauterine pregnancy

Laifer-Narin SL. Ultrasound for Obstetrics Emergencies. Ultrasound Clin . 2011; 6: 177-193

Differential Diagnosis ofThreatened Abortion

1. Undetermined or physiologic (implantation related)

2. Ectopic pregnancy3. Sub-chorionic bleed, found in ~20%

of threatened Ab4. Gestational trophoblastic disease5. Impending spontaneous

miscarriage6. Cervix, vaginal or uterine pathology

ULTRASOUND DIAGNOSIS OF MISCARRIAGE (COMPARING INTERNATIONAL CRITERIA)

This section is too in-depth for most medical students; use it only for the most interested students!

Royal College of Obstetricians and Gynaecologists. The Management of

Early Pregnancy Loss. Green-Top Guideline No. 25. October 2006

Miscarriage: Miscarriage is defined at first scan

when gestational sac with MSD greater than 20 mm an no embryonic contents or CRL > 6 mm with no heart beat

Or subsequently if sac remain empty after at least one week or still no cardiac activity 1 week after initial

How to define miscarriage using ultrasound-comparing and contrasting national guidelines

The Institute of Obstetricians and Gynaecologists

Royal College of Physicians of Ireland

Transvaginal Ultrasound

Embryo > 7 mmNo cardiac

activity

Miscarriage

Gestational sac > 20 mm

No embryo or yolk sac

Miscarriage

How to define miscarriage using ultrasound-comparing and contrasting national guidelines

What is the evidence to support the cut-offs used to diagnose miscarriage?Conclusions First systematic review of ultrasound diagnosis of

miscarriage

Studies are 15–20 years old, small numbers of miscarriage, reference standards were poor (method of miscarriage confirmation)

Various cut-off values used (4–6mm for CRL, 13–25mm for MSD), making pooling of data impossible

Best (most specific) criteria appeared to be MSD > 25mm with a missing embryo or MSD > 20mm with a missing yolk sac

These criteria had a 95% CI of 0.96–1.00, therefore up to 4

out of 100 diagnoses of early fetal demise may be wrong. A single incorrect diagnosis of miscarriage is one too many

Jeve Y et al., UOG 2011 Nov

Abdallah Y, et al. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown–rump length measurements: a multicenter observational study. Ultrasound Obstet Gynecol 2011; 38: 497–502

Prospective multicenter study 1060 patients of IPUV

Conclusions Current definitions used to diagnose miscarriage

by ultrasound are potentially unsafe In order to minimize the risk of a false-positive

diagnosis of miscarriage the following cut-off could be introduced Empty gestational sac or sac with a yolk

sac but no embryo seen with MSD >25 mm

Embryo with an absent heartbeat and CRL > 7 mm

SummarySummary

Data from these studies show that current definitions used to diagnose miscarriage are potentially unsafe

Significant interobserver variability may be associated with a misdiagnosis of miscarriage

Current national guidelines should be reviewed to avoid inadvertent termination of wanted pregnancy

Large prospective studies with agreed reference standards are urgently required

ECTOPIC PREGNANCY

Risk Factors for Ectopic Pregnancy

Prior ectopic Previous tubal surgery History of tubal ligation Intra-uterine contraceptive device History of infertility History of PID History of chlamydia or gonorrhea Smoking

PREGNANCY OF UKNOWN LOCATION

RETAINED PRODUCTS OF CONCEPTION

Retained Products of Conception (RPOC)

RPOC are well-known and troublesome complications after spontaneous or induced abortion and parturition

Patients usually have abdominal pain, bleeding, fever, and an open cervical external os

The diagnosis is based on the sonographic appearance of intrauterine echogenic material

Retained products of conception are generally treated by D&C to empty the uterine cavity. This exposes the uterus to additional potential trauma, with immediate risks such as bleeding, perforation, and infection and late sequelae such as intrauterine adhesions

Oscar Sadan, Abraham Golan, Ofer Girtler, Samuel Lurie, Abraham Debby, Ron Sagiv, Shmuel Evron, Marek Glezerman. Role of Sonography in the Diagnosis of Retained Products of Conception. JUM 2004 23:371-4

Retained products of conception. Intrauterine heterogeneous, mixed echogenic mass with marked internal vascularity in a patient who recently underwent spontaneous abortion

Transvaginal sagittal sonogram of a uterus immediately after repeated D&C. A thin hyperechoic echo is shown, characteristic of an empty uterus.