Omphalocele, also known as exomphalos, is a birth defect of the abdominal (belly) wall. The infant’s intestines, liver or other organs stick outside of the belly through the belly button. The organs are covered in a thin, nearly transparent sac that rarely is open or broken.
As the baby develops during weeks six through 10 of pregnancy, the intestines get longer and push out from the belly into the umbilical cord. By the 11th week of pregnancy, the intestines normally go back into the belly. If this does not happen, an omphalocele occurs. The omphalocele can be small, with only some of the intestines outside of the belly, or it can be large, with many organs outside of the belly.
Because some or all the abdominal (belly) organs are outside of the body, babies born with an omphalocele can have other problems. The abdominal cavity, the space in the body that holds these organs, might not grow to its normal size. Also, infection is a concern, especially if the sac around the organs is broken. Sometimes, an organ might become pinched or twisted, and loss of blood flow might damage the organ.
The Centers for Disease Control and Prevention (CDC) estimates that each year about 775 babies in the United States are born with an omphalocele — in other words, about one in every 5,386 babies. Many babies born with an omphalocele also have other birth defects, such as heart defects, neural tube defects and chromosomal abnormalities.
Causes and Risk Factors
The causes of omphalocele among most infants are unknown. Some babies have omphalocele because of a change in their genes or chromosomes. Omphalocele might also be caused by a combination of genes and other factors, such as the things the mother comes in contact with in the environment or what the mother eats or drinks, or certain medicines she uses during pregnancy.
Recently, CDC researchers have reported important findings about some factors that can affect the risk of having a baby with an omphalocele:
- Alcohol and tobacco use (more than 1 pack a day)
- Certain medications such as selective serotonin-reuptake inhibitors (SSRIs) taken during pregnancy
- Obesity or being overweight before pregnancy