Prevalence:

• 1 in 3,000 births.
• Increased risk in young women and in those with cocaine abuse.

Ultrasound diagnosis:

• Paraumbilical abdominal wall defect, usually to the right side, with associated evisceration of bowel, floating freely in the amniotic fluid with a normally inserted umbilical cord.

Associated abnormalities:

• The incidence of chromosomal abnormalities and genetic syndromes is not increased.

Investigations:

• Detailed ultrasound examination.

Associated complications:

• Bowel atresias or obstruction secondary to volvulus and/or ischemia at the hernial orifice in about 10-30% of cases.
• Fetal growth restriction in 30-60% of cases.
• Spontaneous preterm birth in about 30% of cases.
• Fetal death in 2-4% of cases.

Follow up:

• Ultrasound scans every 4 weeks to monitor growth, amniotic fluid, fetal oxygenation (UA-PI, MCA-PI and DV-PI) and intra-abdominal bowel dilatation.
• In fetuses with abdominal wall defects it is best to monitor growth through estimation of fetal weight by the Sieme formula which uses biparietal diameter, occipitofrontal diameter and femur length, rather than formulas using abdominal circumference.

Delivery:

• Place: hospital with neonatal intensive care and pediatric surgery.
• Time: 38 weeks. Earlier if there is evidence of poor growth, fetal hypoxia or dilatation of intrabdominal bowel (>20 mm).
• Method: induction of labor aiming for vaginal delivery. There is no good evidence that cesarean section is beneficial.

Prognosis:

• Survival: >90%
• Main cause of death: short bowel syndrome.

Recurrence:

• 3%.