Omphalocele is a birth defect that affects the abdominal wall. This congenital abnormality causes the abdominal organs (such as the bowel and liver) to stick outside of the abdomen.
This defect is usually detected during prenatal screening tests, such as an ultrasound test. In some cases, only a small portion of the intestine sticks out of the abdomen, whereas in more severe cases, other organs, such as the liver and spleen, may also extend outside the abdomen.
Instead of being covered in skin, the intestines are covered on a thin membrane (called peritoneum), the size of this membrane depends on the number of extending organs.
During normal fetal development, the abdominal organs naturally first develop outside of the fetal abdomen until around 10 weeks of gestation, but around weeks 12-13 of gestation these organs return inside the abdomen. If not all the organs return into the abdomen, this condition is known as Omphalocele.
It should be noted that most cases of omphalocele are not genetic. If omphalocele is the only finding, the chances of it being caused by a genetic abnormality are only nine percent.
Other birth defects
In 66 percent of cases, babies also suffer from other birth defects in the heart, urogenital system, and central nerve system.
When omphalocele appears as part of a known syndrome, such as Beckwith-Wiedemann syndrome, typical symptoms include overgrowth and an enlarged tongue.
What is the genetic basis of omphalocele?
As of today, no specific gene mutation has been found to cause omphalocele. However, several genes are linked to other syndromes where omphalocele is considered a symptom.
When this congenital defect is detected in the fetus, further genetic testing is required to rule out known syndromes.
The prevalence of omphalocele is 1 in 3,000-4,000 births.
When the opening in the abdominal wall is relatively small, the baby can be delivered via vaginal delivery. However, when the omphalocele is large, cesarean (c-section) is required to prevent a rupture of the omphalocele sac.
There are several treatment options after birth. When the omphalocele is small, surgery can be performed a day or two after birth. Alternately, repairing this defect can be done in stages, the organs are covered with a special material and are then moved back into the body gradually every day for a week. The opening is then closed in a surgery.
In severe cases, the organs are first covered with an artificial membrane to allow the body to grow new skin over the membrane covering. The organs are returned into the body via surgery at around three to four years of age.