An omphalocele is a birth defect where abdominal organs protrude from the belly and lie exposed outside the abdomen. The organs, usually the intestines and liver, are covered in a thin sac. Associated abnormalities can include a smaller-than-normal abdominal cavity or lungs, organ damage or infection (especially if the sac holding the intestines ruptures).
The abdominal wall with an omphalocele fails to develop properly, leaving the abdominal contents covered by a thin membrane. The size and severity of this condition ranges from small, with only part of the intestines protruding, to large, with entire and multiple organs remaining outside of the abdomen.
The incidence of omphalocele ranges from approximately 1 in 4,000 to 1 in 7,000 live births. There is an increased risk of stillbirth in babies with this condition, which is why we strive for early diagnosis and observation.
What causes omphalocele?
The defect is thought to be caused by an abnormality that occurs during the process of body infolding in the embryo at 3 to 4 weeks of pregnancy. While no specific cause is known, omphalocele has been associated with advanced maternal age.
Studies also show that several factors can increase the likelihood of having a baby with omphalocele. Women who are obese or overweight prior to pregnancy are more likely to have a baby with omphalocele, as are women who drink alcohol, smoke cigarettes or take certain kinds of anti-depressants during pregnancy.
Complications of omphalocele
Omphalocele can present as part of a syndrome (meaning multiple organ structures are involved) or as an isolated defect (meaning without other abnormalities). Small abdominal wall defects that contain only bowel are associated with an increased risk of chromosomal abnormalities (considered to be the baby's "blueprint").
Other organ abnormalities vary greatly, ranging from single minor abnormalities that are not life-threatening for the baby to multiple complex life-threatening abnormalities that influence long-term prognosis more than the omphalocele itself. Genetic testing is strongly recommended due to the multiple studies that have documented a high rate of chromosomal abnormalities.