Fetal omphalocele is a congenital defect of the abdominal wall that allows some of the abdominal organs to protrude through it. A translucent membrane or sac covers the protruding organs. The severity of the condition varies from child to child.
In a normal baby, the intestines grow and develop outside the abdomen in the umbilical cord until about the tenth week of pregnancy. After this time the intestines return into the abdomen; when this fails to happen, a fetal omphalocele occurs.
When the defect is minor, a small portion of the baby's intestines protrude through the umbilical cord to the outside of the body. When the defect is large, the intestines and other organs such as the liver and spleen can also be present outside the abdominal wall.
More than half of all babies born with an omphalocele are born with other birth defects including abnormalities of the spine, heart, digestive system, urinary system and limbs. Additionally, about one out of every three infants born with this condition also has a genetic abnormality.
Approximately one in every 5,000 births is affected by a small omphalocele defect, and one in every 10,000 births is affected by a large one. Because this condition may be linked to genetics, the chance of a family having another child with this condition is one in 100.
Diagnosis & Treatment
Fetal omphalocele is diagnosed by ultrasound (sonogram) examination prior to birth generally in the second or third trimester. Evaluation of the bowels is part of the routine ultrasound examination done by many obstetricians as part of their routine prenatal care around the 20th week of pregnancy. It is recommended that a baby diagnosed with this condition be referred to a pediatric cardiologist to undergo a fetal echocardiogram (an ultrasound of the baby's heart while the infant is still in the womb). This is performed because many babies born with an omphalocele also have congenital heart defects. The echocardiogram provides a much more in-depth evaluation of the heart.
After fetal omphalocele is diagnosed, the staff at Ann & Robert H. Lurie Children’s Hospital of Chicago counsels the parents and prepares them for what to expect when their baby is born. Plans are made to assure that the baby is delivered in a hospital that has a neonatal intensive care unit (NICU) with a neonatologist present at the delivery.
After birth, the baby is stabilized and then transferred via ambulance to Lurie Children's to begin treatment. In a baby with a small omphalocele, surgery is performed shortly after birth to return the intestines back into the abdomen and to close the hole in the abdominal wall.
When the omphalocele is large, surgery is generally not performed right away. First, a topical antibiotic solution is applied to the protruding abdominal organs, and a dressing is wrapped around the abdomen. Because the infant may have breathing difficulties during this time, they may need help from a breathing machine called a ventilator. When the baby is stable and any other associated conditions are cared for, they may go home to heal. This allows time for the baby's skin to grow over the sac, which normally takes several weeks. At about one-year-old, surgery is performed to close the defect in the abdomen.
The long-term outlook for these children depends greatly on the size of the omphalocele and whether they are born with other birth defects or genetic problems. Babies diagnosed with a small omphalocele and no other defects have an excellent survival rate and are expected to have a normal life expectancy. Babies born with a large omphalocele may have long-term problems with digestion, infection or other abnormalities depending on their other defects. However, diagnosing the problem before birth increases their chance of survival because treatment can begin as soon as they are born.