Omphalocele

An omphalocele is a congenital condition (meaning present at birth) where the intestines or other abdominal organs protrude outside the belly through the belly button. It can be considered physiologic up to around the 11th to 12th week of gestation. During early fetal development, the intestines normally herniate outside the abdominal cavity and then return back into the abdomen by the end of the first trimester. If the intestines or other organs do not return to the abdominal cavity by this time, the omphalocele is considered pathologic.

An omphalocele can be small, with only part of the intestine protruding through the abdominal cavity, or large — with the intestine, liver, spleen, and other abdominal organs pushing through. The abdominal cavity itself might also be small because it didn’t develop fully during pregnancy.

At Boston Children’s Hospital, we provide unparalleled care in evaluating and treating omphaloceles. Our team of fetal surgeons, maternal-fetal medicine specialists, pediatric surgeons, pediatric cardiologists, fetal radiologists, and other specialists collaborate with you and your pregnancy care team to provide a comprehensive approach that starts with your first prenatal visit and continues through delivery, postnatal care, and beyond.

An omphalocele doesn’t typically cause symptoms in a pregnant person, but can be seen on a prenatal ultrasound because the fetus’ intestines and/or other organs protrude through the abdomen.

Many babies born with an omphalocele have other health conditions. Approximately 30 percent have a genetic disorder, most commonly Trisomy 18 and Trisomy 13, Trisomy 21, or Turner syndrome. Other infants born with omphalocele may have Beckwith-Wiedemann syndrome. More than half of babies with omphalocele have malformations of other organs or body parts, most commonly the spine, digestive system, heart, urinary system, and limbs.

During pregnancy, a fetus’ intestines usually protrude into the umbilical cord as they grow but return to the abdomen by around week 11 of development; an omphalocele occurs when this doesn’t happen. While omphaloceles may be related to a genetic syndrome, doctors don’t know what causes them or whether anything can be done during pregnancy to prevent them.

A small omphalocele that involves only the protrusion of the intestines occurs in one in 5,000 pregnancies, whereas a large omphalocele that causes a protrusion of the intestines, liver, and other organs happens to one in 10,000. Omphaloceles are more common in boys than girls.

Researchers are studying risk factors for omphaloceles. It has been found that when an omphalocele is isolated and no other malformations are present, the possibility of one happening in a future pregnancy is 1 percent. Some families have had an omphalocele inherited as an autosomal dominant or X-linked recessive trait. In these cases, the chance for recurrence is higher.

Omphaloceles are mostly detected before birth during routine prenatal ultrasounds. A fetal MRI can provide additional information by helping to characterize the omphalocele and detect additional abnormalities. Our team of fetal imaging experts, including technologists and radiologists, use the images from the ultrasound and MRI to provide a comprehensive and detailed assessment of the fetus’ anatomy and well-being. In addition, a heart ultrasound (echocardiogram) can help diagnose other associated problems with the fetal heart, and amniocentesis can look for chromosomal abnormalities or genetic conditions.

Treatment for omphalocele depends on its size and severity. Typically, surgeons repair a small omphalocele a day or two after birth by returning your baby’s organs to the abdomen and closing the opening in the abdominal wall. For large omphaloceles, surgeons perform surgical repair in stages:

• Gradual compression: Because the abdomen may be small and underdeveloped, it may not be able to hold all the organs at the same time. In that case, a process called “paint and wait” is used, where the exposed sac is covered with a protective dressing and treated with topical antiseptics to prevent infection and promote healing. This approach allows the sac to form a new layer of skin (epithelialize) and shrink over time, giving the infant’s abdominal cavity a chance to grow and accommodate the herniated organs. Definitive surgical repair is delayed until the infant is older and in better health, reducing the risk of complications associated with immediate surgery.
• Surgical closure: The abdominal wall is closed surgically once the organs have been returned to the abdominal cavity.

If the abdominal cavity is small and underdeveloped, your baby may have difficulty breathing as organs are returned to the abdomen, so they may receive help breathing from a mechanical ventilator during this process. Many infants need a feeding tube to supplement their short- or long-term nutrition.

The long-term outlook for an omphalocele depends on its size, impact on the organs, and other conditions that may be present. Common complications may include:

• Feeding difficulties
• Bowel obstruction
• Gastroesophageal reflux
• Infection
• Inguinal hernias

Babies with large omphaloceles are at greater risk of long-term health issues, including problems with breathing, heart function, feeding, and growth and development.

At Boston Children’s, the Fetal Care and Surgery Center and the Department of Surgery work together develop a comprehensive treatment plan for your child. We collaborate with clinical departments across Boston Children’s and work with you to acheive the best possible outcome and to help ensure your child is on a path to recovery.