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Key Points
Defect in ventral abdominal wall characterized by absent abdominal muscles, fascia, and skin. Defect is covered by membrane that consists of peritoneum and amnion.
Incidence 1 in 4000 to 1 in 7000 livebirths.
Principal sonographic diagnostic feature is umbilical cord insertion into the membrane covering the defect at a location distant from the abdominal wall.
Differential diagnosis includes gastroschisis, body-stalk anomalies, pentalogy of Cantrell, and Beckwith–Wiedemann syndrome.
There is a high incidence of both associated malformations and chromosome abnormalities. Prenatal karyotype is indicated. Fetal echocardiogram is recommended.
Serial prenatal sonograms should be performed to assess fetal growth and amniotic fluid volume.
Delivery at a tertiary care center provides optimal care for the newborn. Mode of delivery is debatable, except for cases of giant omphalocele or extracorporeal liver, in which cesarean section should be performed.
Even with primary surgical repair, prospective parents should anticipate a long hospitalization for their neonate.
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Omphalocele is a defect in the ventral abdominal wall that is characterized by an absence of abdominal muscles, fascia, and skin. The defect is covered by a membrane that consists of peritoneum and amnion. It can vary in size from a few centimeters to most of the ventral abdominal wall. Unlike gastroschisis, in omphalocele, the umbilical cord inserts into this membrane at a location distant from the abdominal wall (deVries, 1980). The defect is thought to be caused by an abnormality that occurs during the process of body infolding at 3 to 4 weeks of gestation (Dimmick and Kalousek, 1992). At that time, 3 folds occur simultaneously, and each is associated with a distinct type of omphalocele. Cephalic folding defects result in a high or epigastric omphalocele. An example of this is pentalogy of Cantrell (see Chapter 61), which consists of an epigastric omphalocele, anterior diaphragmatic defect, sternal cleft, pericardial defect, and associated intracardiac defects (Figure 62-1A) (Cantrell et al., 1958). A defect in lateral folding results in the classic omphalocele (Figure 62-1B) with a midabdominal defect. A defect in caudal folding results in a low or hypogastric omphalocele, as seen in bladder or cloacal exstrophy (see Chapters 64 and 65) (Duhamel, 1963; Meller et al., 1989; Vasudevan et al., 2006). The spectrum of severity of abdominal wall abnormalities can vary from a small umbilical hernia to a large defect with extrusion of the abdominal viscera.
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The incidence of omphalocele ranges from approximately 1 in 4000 to 1 in 7000 livebirths (Baird and ...