An omphalocele, which is also referred to as exomphalos, is a rare congenital defect of the abdominal wall. The defect manifests in infancy as a protrusion of the bowels, liver, and various abdominal organs through an opening in the muscles near the umbilical cord insertion. As a result, these babies tend to have a protruding umbilicus.
Omphalocele is estimated to occur in approximately 1 in every 4000 – 7000 births, and more than 6 out of every 10 of these babies will have anomalies of other organs or systems in the body. The most commonly associated abnormalities are in the urinary and digestive system, as well as in the heart, spine and limbs.
The cause of omphalocele is unknown. Normally, during intrauterine development, the intestines project into the umbilical cord as they grow. This natural phenomenon happens between the 6th and 10th weeks of pregnancy. Around the 11th week, the intestines usually return into the abdomen, but failure in this remigration results in an omphalocele. There are several theories that try to figure out why omphalocele occurs. Some postulate that genetic factors may be involved, while others suggest it may be a combination of genes and environment.
Some risk factors for a baby developing an omphalocele have been recently reported by the CDC. Their findings suggest that infants born to women who smoke tobacco or drink alcohol during pregnancy have a greater risk for omphalocele. They also found that women on certain medications during gestation, like selective serotonin-reuptake inhibitors (SSRIs), had a higher chance of bearing a baby with a defective abdominal wall. In addition to these, obesity was also identified as a risk factor for omphalocele.
Diagnosis and Treatment
Omphalocele can be diagnosed before or after birth. It is usually detected during the second trimester of a pregnancy or afterwards on ultrasound. If a baby is found to have omphalocele, a fetal echocardiogram is also frequently done to ascertain if there are cardiac abnormalities as well. Furthermore, x-rays may be ordered to check for anomalies in other organs and systems.
Treatment varies depending on the severity of the omphalocele, the age, overall health and medication tolerance of the infant, and the treatment preferences of the parents. Surgical repair as soon as possible is suitable for a small omphalocele, in order to place the protruded abdominal organs back into their physiological position. The defect in the abdominal wall is also closed during this procedure to prevent recurrence, tissue damage and infection. A large omphalocele with multiple organ involvement requires complex surgery, which is done in stages, because the infant’s abdomen may be too small and undeveloped to have all the organs fit.
Following the operation, a baby may be hospitalized for a few days, weeks or months, depending on the extent of the omphalocele and the involvement of other organs or systems. Follow-up care is required by a pediatrician and pediatric surgeon. Infants who do not have any other associated defects usually have a very good long-term outlook. However, conditions associated with a large omphalocele, like hypoplastic lungs, may cause significant health issues in the long-term, and thus require very close monitoring.
Reviewed by Liji Thomas, MD