What Is an Omphalocele?

An omphalocele is a congenital defect (occurs at birth) that happens as a result of an abnormality in fetal development. It involves an opening in the muscles of the abdomen (located at the site where the umbilical cord is). This anomalous opening allows for the baby’s organs to protrude through the muscle wall so that the organs are on the outside of the body. The organs are covered by a clear layer of mucous membranes, which serves to help protect them.

An omphalocele can be small and involve only a portion of the intestine, or it can be very large, with several of the organs of the abdomen (including the intestines, liver and spleen) protruding through the opening. The exact cause of an omphalocele is not completely understood, but some cases are believed to be linked to an underlying genetic disorder.

Symptoms

The primary symptom of an omphalocele is the protrusion of the abdominal organs through the abdominal muscle wall. It’s common for infants born with an omphalocele to have other congenital birth defects as well, such as heart defects, Beckwith-Wiedemann syndrome, the Shprintzen-Goldberg syndrome and more. 

Beckwith-Wiedemann syndrome is considered an overgrowth syndrome that may involve several parts of the body (such as organ or body overgrowth). Infants born with Bechwith-Wiedemann syndrome are much larger than other children of the same age. The severity the syndrome may vary from person to person. Shprintzen-Goldberg syndrome is a rare disorder involving deformities of the connective tissue, skeletal system, craniofacial (bones of the head and face) and heart.

Other symptoms that may accompany omphalocele include:

• Slow growth before birth (called intrauterine growth retardation)
• Abnormally small abdomen (due to malformation during fetal development)
• Undeveloped lungs (as well as a chest wall that is smaller than normal to allow for normal lung formation)
• Respiratory insufficiency (requiring mechanical ventilation to breathe)
• Gastrointestinal problems (such as acid reflux)
• Feeding problems
• Multiple health problems (usually associated with large omphaloceles)

Difference Between Omphalocele and Gastroschisis

Gastroschisis is an abdominal wall birth defect that is similar to an omphalocele; the primary difference is where the opening is located in the abdominal muscle wall. An omphalocele’s opening is in the center of the umbilical wall (where the umbilical cord meets the abdomen). Gastroschisis involves an opening to the right of the umbilical cord, through which the large and small intestines (and possibly other organs) protrude.

Unlike in an omphalocele, gastroschisis does not have a membrane that covers the exposed organs. This lack of membrane covering causes complications, many of which are not present in those with omphalocele. One such complication involves organs that become damaged due to the direct contact with amniotic fluid in the uterus. This may result in immune and inflammatory responses that damage intestinal tissue.

Most infants with gastroschisis are small at birth due to growth retardation in utero (in the womb); many are premature at birth. It may take them a while to catch up developmentally and long-term health problems related to feeding or bowel problems (from intestinal damage) may occur.

Infants born with gastroschisis do not usually have any other birth defects and they rarely have a genetic condition or chromosomal abnormalities, unlike those with omphalocele. In fact, according to a 2014 study, infants with omphalocele were more likely to be diagnosed with at least one other congenital abnormality such as pulmonary hypertension (an increase in pressure in the pulmonary artery). Infants born with omphalocele were also found to be at a much higher mortality (death) rate than those with gastroschisis.

Nearly half of the babies who are born with an omphalocele also have a genetic disorder called Beckwith-Wiedemann syndrome, along with the symptoms associated with this disorder.

Causes

Omphalocele is caused by an error in the development of the digestive tract. During normal fetal development, the intestines protrude through the umbilical cord while the intestines are developing, but as the fetus continues to develop, the intestines normally recede back into the abdomen. When an omphalocele occurs, the intestines do not recede.  It’s not completely clear exactly why this happens. There have not been any specific genetic mutations known to cause this birth defect, but it is surmised that multiple genetic and environmental factors may influence the development of an omphalocele. 

Diagnosis

A diagnosis of an omphalocele is often made during an ultrasound during the second or third trimester of pregnancy.

Once an omphalocele is detected, an ultrasound of the baby’s heart (called a fetal echocardiogram) will be ordered to ensure there is not an associated heart defect. Once the baby is born, the diagnosis will be confirmed by a physical examination performed by the healthcare provider. An X-ray will be taken after the infant's birth to check for problems with any organs.

Treatment

Omphalocele treatment will depend on several factors, including:

• Age (specifically whether the infant is premature)
• Symptoms
• General health
• The size of the omphalocele
• The size of the infant’s abdomen (when the abdomen is abnormally small, treatment will be more complicated)

A small defect is normally treated successfully with a surgical procedure, aimed at putting the organs back into the baby’s abdomen and closing the abdominal wall opening after birth. A large omphalocele with multiple abdominal organs involved (such as the intestines, liver, and spleen) may involve treatment in several stages. Treatment for large omphaloceles may include:

• A sterile covering placed over the protruding organs to help protect them
• Surgery performed in multiple stages. If the baby’s abdomen is not fully developed, it may not be large enough to hold all of the organs at once. In this instance, the surgeon will put the organs back into the abdomen gradually, over a time span of several days or weeks.
• Surgical closure of the abdominal wall (once each of the organs has been placed inside)
• Assistance in breathing (via a mechanical ventilator). If the infant’s abdomen is too small and the organs are swollen; this can result in difficulty breathing. The infant may need help with breathing until the swelling subsides and the abdominal cavity grows to capacitate the baby’s organs.

Complications

There are several complications that may occur, both before and after the treatment of an omphalocele. The risk is higher with larger omphaloceles that require several stages of treatment. The complications may include:

• Infection—particularly if the mucous membrane covering the organs breaks (which is likely to occur prenatally or during delivery)
• Organ damage—if an organ is twisted or pinched it can become damaged as a result of loss of blood supply
• Feeding difficulties, failure to grow and develop normally, GI reflux and inguinal hernias may occur after surgical repair

Prognosis

A prognosis is the expected outcome of treatment for a specific condition. The prognosis is based on research study data involving studies of others with the same condition who received treatment. The prognosis of an omphalocele depends on many factors, including:

• The size of the omphalocele
• Any damage that may have occurred to the organs (from a loss of blood flow)
• Other congenital birth defects or health issues

Study

A 2019 study, involving long-term follow-up evaluation in school-age children who were treated as infants for omphalocele discovered some facts about the child’s cognition, health status, quality of life and behavior, the study concluded:

• Those who were treated for an isolated (no defects other than an omphalocele), minor omphalocele did not require any type of long-term follow-up treatment for behavioral, cognitive or health problems.
• 81% of those who were treated for a “giant omphalocele” (over 5 centimeters or 1.9 inches), were reportedly normal when they reached school age, with no behavioral, cognitive or health problems.
• Those with multiple congenital defects and giant omphaloceles had the lowest scores for risk for delayed cognitive function at school age; this group was recommended for long-term follow-up care and intervention.

A Word From Verywell

Coping with a new baby with any type of birth defect is often very difficult, particularly for the new parents, grandparents, and other family members. While it’s important to find credible resources and educate yourself about what the future may bring, it’s just as vital not to automatically expect the worst. Many children born with an omphalocele go on to live perfectly normal, healthy lives. Make sure to discuss your child’s treatment plan and prognosis (expected outcome of treatment) with the surgeon, pediatrician and other knowledgeable healthcare professionals.

Connecting with other parents who have gone through the challenges of having an infant, born with a birth defect (or those who are expectant parents of a child with a developmental abnormality) can be very helpful. There are many online sources of support, such as The March of Dimes, the National Organization of Rare Diseases, and more. TheCenters for Disease Control and Prevention (CDC) has an inclusive list of various local and national support networks and other resources (such as financial help, navigating insurance claims, educational information and much more) for parents.