What is an omphalocele?
An omphalocele is a rare abdominal wall defect in which a baby's intestines, and occasionally the liver or other organs, remain outside of the abdomen. This is caused by a defect in the development of the muscles of the abdominal wall. It can vary in size, from a few centimeters to most of the abdominal wall.
Receiving the news that your baby has an omphalocele can feel scary and overwhelming. Yet the Colorado Fetal Care Center is at the forefront of diagnosing and treating this condition. We also perform state-of-the-art surgeries that enable babies to live healthy, full lives.
An omphalocele is a birth defect where abdominal organs protrude from the belly and lie exposed outside the abdomen. The organs, usually the intestines and liver, are covered in a thin sac. Associated abnormalities can include a smaller-than-normal abdominal cavity or lungs, organ damage or infection (especially if the sac holding the intestines ruptures).
The abdominal wall with an omphalocele fails to develop properly, leaving the abdominal contents covered by a thin membrane. The size and severity of this condition ranges from small, with only part of the intestines protruding, to large, with entire and multiple organs remaining outside of the abdomen.
The incidence of omphalocele ranges from approximately 1 in 4,000 to 1 in 7,000 live births. There is an increased risk of stillbirth in babies with this condition, which is why we strive for early diagnosis and observation.
What causes omphalocele?
The defect is thought to be caused by an abnormality that occurs during the process of body infolding in the embryo at 3 to 4 weeks of pregnancy. While no specific cause is known, omphalocele has been associated with advanced maternal age.
Studies also show that several factors can increase the likelihood of having a baby with omphalocele. Women who are obese or overweight prior to pregnancy are more likely to have a baby with omphalocele, as are women who drink alcohol, smoke cigarettes or take certain kinds of anti-depressants during pregnancy.
Complications of omphalocele
Omphalocele can present as part of a syndrome (meaning multiple organ structures are involved) or as an isolated defect (meaning without other abnormalities). Small abdominal wall defects that contain only bowel are associated with an increased risk of chromosomal abnormalities (considered to be the baby's "blueprint").
Other organ abnormalities vary greatly, ranging from single minor abnormalities that are not life-threatening for the baby to multiple complex life-threatening abnormalities that influence long-term prognosis more than the omphalocele itself. Genetic testing is strongly recommended due to the multiple studies that have documented a high rate of chromosomal abnormalities.
Omphalocele is often detected from a routine prenatal ultrasound. The condition can also trigger abnormal results on prenatal blood screening tests. If not discovered during pregnancy, it becomes obvious when the baby is born.
Babies born with omphalocele can be treated in a number of ways depending on the size of the defect, associated abnormalities and gestational age at delivery. We have found that a team approach is best for families who’ve received this diagnosis. We offer comprehensive counseling and advice for parents with a fetus diagnosed with this anomaly. In addition to maternal and fetal medicine specialists, the parents will be able to meet with specialists in pediatric surgery, genetics, neonatology and pediatric cardiology.
What is the impact of this diagnosis on my pregnancy?
After receiving an omphalocele diagnosis, some patients might decide to terminate their pregnancy. After a decision has been reached regarding the continuation of the pregnancy, our team will then focus on detecting preterm labor and intrauterine growth restriction (a condition where the baby is not growing enough while in the uterus). Both of these complications are frequently associated with omphalocele.
There will be many more ultrasounds performed in a pregnancy complicated by omphalocele to assess the baby’s growth and the amount of amniotic fluid. In addition, during ultrasound assessment, we observe for occasional rupture of the omphalocele membrane which can expose the herniated intestines to amniotic fluid. The goal with omphalocele is to deliver the baby as close to term as possible.
C-sections are only recommended for specific cases, usually when the defect in the fetal abdomen measures 5 cm or greater or if the liver is entirely outside the body.
Omphalocele treatment plans depend on the number of organs involved and how much of those organs remain outside of the belly at birth. If only parts of the intestines are protruding, surgeons return them to the abdomen soon after birth and close the opening in the abdominal wall. If the omphalocele is large with multiple organs exposed, or there are associated respiratory problems, physicians usually take a phased approach. In the most severe cases, doctors will take time to allow the body to grow skin over the membrane. Ace wraps can then be used to develop space to accommodate the organs, with repair of the defect occurring at 1-2 years of age. Currently, there are no fetal (in utero) interventions offered to treat omphalocele.
Long-term outcomes for babies with omphalocele
Modern surgical advances have made life not only possible, but also probable, for children born with this birth defect. The omphalocele survival rate for babies with no additional abnormalities is 90%. Those with other defects have a survival rate of 70%.
Babies with multiple organs exposed, as well as related abnormalities such as smaller-than-average lungs, can experience ongoing breathing and heart problems. These children require long-term care and monitoring from a multidisciplinary team of specialists.
Learn more about the Colorado Fetal Care Center, including our latest outcomes and how to find the right fetal care center for you.
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