**5.2. Omphalocele**

#### *5.2.1. Pregnancy management*

Omphalocele and gastroschisis are the most common fetal abdominal wall defects. By the end of the first trimester (11–14 weeks), almost all omphaloceles can be detected by prenatal ultrasound examination [77].

• Genetic assessment. Multiple chromosomal abnormalities have been reported among fetuses with omphalocele. As many as 60% of omphaloceles not containing liver are associated with fetal aneuploidy, particularly trisomy 18 or 13 [77, 78]. Fetal genetic studies should be offered if omphalocele or related body wall defects are identified prenatally, because of the high risk of aneuploidy. It is reasonable to offer amniocentesis for genetic testing for Beckwith-Wiedemann syndrome, but this testing is complicated and should be discussed with a geneticist [77]. There is a 10–20% risk of Beckwith-Wiedemann syndrome in fetuses with apparently isolated omphalocele on ultrasound.


#### *5.2.2. Delivery management*

the biparietal diameter, occipitofrontal diameter, and femur length measurements [76]. Oligohydramnios may be related to fetal growth restriction and is a risk factor for cord compression and its sequelae. Polyhydramnios is less common, but an important finding because it is often caused by dysfunction of the gastrointestinal tract due to bowel

• Assessment of fetal bowel. Gastric dilatation, bowel dilatation, and bowel wall thickening have been considered poor prognostic signs by several investigators [73]. If these significant changes are observed prior to 34 weeks, a course of glucocorticoids is suggested for

• Antepartum fetal surveillance. Fetal growth restriction and amniotic fluid abnormalities are commonly accepted indications for increased antepartum fetal surveillance. The pre-

Gastroschisis increases the risk of preterm delivery; delivery should occur in a facility with appropriate resources for caring for these neonates. Gastroschisis alone is not an indication

The decision on timing of delivery is based on a combination of factors, including gestational age, ultrasound findings (fetal growth profile, AFV, appearance of fetal bowel), and fetal testing results (NST, BPP, umbilical cord Doppler if fetal growth restriction is present). In the absence of standard obstetric indications for abdominal delivery, a trial of labor rather than scheduled cesarean birth for most patients is suggested. Cesarean delivery is reasonable if the liver is significantly herniated because of the theoretic risk of dystocia and trauma. Delivery of pregnancies complicated by fetal gastroschisis at 37 or 38 weeks of gestation is suggested to minimize neonatal morbidity and mortality and avoid the possibility of term (39–40 weeks) stillbirth; however, there is no consensus on the optimum timing of delivery

Omphalocele and gastroschisis are the most common fetal abdominal wall defects. By the end of the first trimester (11–14 weeks), almost all omphaloceles can be detected by prenatal

• Genetic assessment. Multiple chromosomal abnormalities have been reported among fetuses with omphalocele. As many as 60% of omphaloceles not containing liver are associated with fetal aneuploidy, particularly trisomy 18 or 13 [77, 78]. Fetal genetic studies should be offered if omphalocele or related body wall defects are identified prenatally, because of the high risk of aneuploidy. It is reasonable to offer amniocentesis for genetic testing for Beckwith-Wiedemann syndrome, but this testing is complicated and should be discussed

atresia [73].

fetal maturation [73].

490 Congenital Anomalies - From the Embryo to the Neonate

*5.1.2. Delivery management*

of these pregnancies [73].

*5.2.1. Pregnancy management*

ultrasound examination [77].

**5.2. Omphalocele**

cise timing and frequency of testing is arbitrary [73].

for preterm intervention or cesarean delivery [73].

Delivery should be planning at a tertiary care center. In the absence of standard indications for early delivery, it is reasonable to await spontaneous labor or achieve 39 weeks of gestation. Preterm birth offers no advantage to affected neonates and is associated with increased morbidity and mortality. There is no evidence that cesarean delivery improves outcome in uncomplicated omphalocele; surgery should be reserved for usual obstetric indications [77]. However, some pediatric surgeons have recommended cesarean delivery for fetuses with giant omphaloceles (defined as an omphalocele containing >75% of the liver and defect greater than 5 cm) in an attempt to avoid dystocia, rupture, infection, and hemorrhage [80]. Visceral trauma has also been reported after cesarean delivery [77].
