Approach to Fetal Anomalies done By :

leen saifan

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Congenital anomalies

Is a term that describe structural, behavioral, functional, and metabolic disorders present at birth or develops later in life.

•Divided into :• 1-Malformation:-

• It`s a primary error results in complete or partial absence of a structure or alterations of its normal configuration.

• Occur during organogenesis.

• Mostly during the first 8 weeks of gestation.

• 2-Deformation:

• Late change in previously normal structure.

• It results from mechanical forces on the fetus which is either extrinsic or intrinsic causes

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Epidemiology• Congenital malformations are a major cause of infant morbidity

and mortality in the world.

• Major congenital abnormality occur in 2 - 3% of live births.

• Minor congenital abnormality occur in 15% of live born infants.

• This incidence increases in pre-term and small for gestational age infants.

• Birth defects are the leading cause of infant mortality, accounting for approximately 21% of the infant deaths.

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Etiology of Congenital Malformations

Unknown - 60%

Multifactorial - 20%

Single-gene - 7.5%

Chromosomal - 6%

Infections - 2-3%

Maternal medical disorders - 1.5%

Maternal medication - 1-2%

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prenatal diagnosisis the identification of a disease in the fetus prior to birth frequently follows a prenatalscreening test.

Benefits :1-certain abnormalities may treat in utero.2-The option of termination.3-To transfer certain cases in utero to deliver in a tertiary care center.4-To prevent maternal psychological trauma.5-allowing couples to prepare for the birth of an affected child.

prenatal screening testnon-invasive in nature and are used only to determine the possibility of a particular condition and measure risk.

Including :1- history taking and physical examination in the booking visit:1. Maternal age if above 35 years.

2. Previous history of child with birth defect or mental retardation.

3. Previous history of child died in the neonatal period.

4. Recurrent abortion in the first trimester.

5. Parental consanguinity.

6. Exposure to infections or excessive medications.

7. Family history of birth defect, chromosomal abnormality, or single gene defect8.Fundal height abnormal, malpresentation

3-Serum screen marker test :1. Alpha fetoprotein:

▪ It is a glycoprotein produced by the fetal yolk sac and fetal liver (16-18 GA).

▪ Elevated level found in: wrong dating, multiple gestation, fetal demise, liver tumor. NTD, ventral wall defect.

2. HCG.

3. Inhibin A

4. Pregnancy specific proteins (e.g. PAPP-A)5. unconjugated oestriol(E3)

2-ultrasonography

Prenatal diagnosis indication :any abnormal findings in history and physical examination,ultrasonography or Serum screen marker testthat suspect disease in the fetus

3-ultrasonography :used as screening or diagnostic tool for congenital malformation and chromosomal diseases during 12 week dating or 20 week anomaly scan.

Omphalocele :The diagnosis of exomphalos is based on the demonstration of the mid-line

anterior abdominal wall defect, the herniated sac with its visceral contents and the umbilical cord insertion at the apex of the sac

GASTROSCHISIS:evisceration of the intestine occurs through a small abdominal wall defect located just lateral and usually to the right of an intact umbilical cord. The loops of intestine lie uncovered in the amniotic fluid

Spina bifida :The diagnosis of spina bifida has been greatly enhanced by the recognition of associated abnormalities in the skull and brain.These include frontal bone scalloping (lemon sign), and "absent" cerebellum or abnormal anterior curvature of the cerebellar hemispheres (banana sign)

Spina bifida at the lower end of the spinal cord.

Absence of the cranial vault and brain above the base of the skull and orbits.

Extrusion of brain and meninges through a midline skull defect.

Cell-free fetal DNA (cffDNA) :Fragments of DNA are released from fetuses and their placenta into the maternal circulation. The concentration of cffDNA increases with gestation from around 10% at 10 weeks of gestation.By amplifying the cffDNA using PCR, it makes it possible to check the fetal genotype.Now , it is used for diagnosis of :1-Fetal single gene disorders.2-Fetal blood group n cases of RhD alloimmunization, to determine the sex of the fetus in X-linked disorders, or to diagnose skeletal dysplasias.

Invasive testing

Chorion villus sampling

A procedure aims to take a sample of Fetal trophoblast cells rapidly dividing cells from the developing placenta. This is done either by passing a needle under ultrasound guidance through the abdominal wall and myometrium into the placenta or by passing a fine catheter (or biopsy forceps) through the cervix into the placenta .The additional overall risk of miscarriage from CVS is approximately 2%. This is in addition to the background (natural) risk of miscarriage for a first trimester pregnancy. Many laboratories can provide a result for common aneuploidies (T21, 18, 13, X and Y) within 48 hours for a CVS sample.Full culture results take approximately 7–10 days and results for genetic disorders take varying amounts of time.

The woman is scanned initially:To confirm that the pregnancy is viable prior to the procedure.

To ensure that it is a singleton pregnancy (prenatal diagnosis in multiple pregnancy is more complex).

To confirm gestational age (CVS should not be performed before 10 weeks’ gestation).

To localize the placenta and determine whether a transabdominal or transcervical approach is more appropriat.

Indications :to diagnose1- chromosomal diseases for example Down’s syndrome .2- genetic conditions such as cystic fibrosis or thalassaemi.3-inborn error of metabolism .

Complications:1-miscarriage.2-infection.3- limb deformity especially if is done befor 10 weeks.

Amniocentesis

Amniotic fluid contains amniocytes and fibroblasts shed from fetal membranes, skin and the fetal genitourinary tract. An amniocentesis procedure takes a sample (15–20 ml) of amniotic fluid that contains these cells. This is done by passing a needle under continuous direct ultrasound control through the abdominal wall and myometrium into the amnioticcavity and aspirating the fluid..The estimated total pregnancy loss (background and procedure-related loss combined) is 1.9Like cvs, result for common aneuploidies (T21, 18, 13, X and Y) within 48 hours for an amniocentesis sample. Full culture results take approximately 7–10 days and results for genetic disorders take varying amounts of time.

Indications :1- chromosomal diseases for example Down’s syndrome .

2- genetic conditions such as cystic fibrosis or thalassaemi.

3-to check for fetal viral infections, for example cytomegalovirus.

4-In the past, it was also used for biochemical tests, for example alpha-fetoprotein (AFP) and acetylcholinesterase for spina bifida

Complications:1-miscarriage

2-infection

3-amniotic fluid leakage

4-rupture of membrane ,preterm labor

5-fetal trauma

CordocentesisA needle is passed under ultrasound guidance through the abdominal wall and myometrium and, most commonly, into the umbilical cord at the point where it inserts into the placenta. This point is chosen because the umbilical cord is fixed and does not move.Cordocentesis can be performed from about 20 weeks’ gestation

Indications:1-when a rapid full culture for karyotype is needed( results within 48-72h).2-when fetal blood is needed in suspected severe fetal anaemia or thrombocytopaenia.3-blood transfusion in utero.

Complications :1-cord hematoma.

2-bleeding from cord vessel.

3-fetal bradycardia.

4-fetal death.

5-infection.

6-preterm labour.

Care after any invasive test :The woman should be advised to avoid strenuous exercise for the next 24hours.She should be advised that while she may experience some mild abdominalpain, it should be relieved by paracetamol.She should be advised that if she has any fever, bleeding, pain not relieved by paracetamol or leakage of fluid vaginally she should seek medical advice, and told how to access thisIf the woman is RhD negative, an appropriate dose of anti-D should be

administered ..

Thank you