What is an omphalocele?
An omphalocele is a birth defect, which is an abnormality that occurs before birth as a fetus is forming in its mother’s uterus. Some of the abdominal organs protrude through an opening in the abdominal muscles in the area of the umbilical cord.
An omphalocele is a type of abdominal wall defect in which the intestines, liver and occasionally other organs remain outside of the abdomen in a sac because of a defect in the development of the muscles of the abdominal wall . The omphalocele can be small, with only a small loop of intestines present outside the abdomen, or large, containing most of the abdominal organs. In severe cases surgical treatment is made more difficult because the infant’s abdomen is abnormally small because it had no need to expand to accommodate the developing organs.
An omphalocele develops as a baby grows inside the mother’s womb. The muscles in the abdominal wall (umbilical ring) do not close properly. As a result, the intestine remains outside the umbilical cord. An omphalocele can be clearly seen, because the abdominal contents stick out (protrude) through the belly button area. A translucent membrane covers the protruding organs.
When an omphalocele is isolated (no other birth defects are present), the risk for it to happen in a future pregnancy is one percent or one in 100. There are some families that have been reported to have an omphalocele inherited as an autosomal dominant or X-linked recessive trait. In these cases, the chance for reoccurrence would be higher.
Many babies born with an omphalocele also have other abnormalities. The chance for reoccurrence depends upon the underlying disorder:
- Thirty percent have a chromosomal (genetic) abnormality, most commonly Trisomy 13, Trisomy 18, Trisomy 21, Turner syndrome, or triploidy.
- Some infants with omphalocele have a syndrome known as Beckwith-Wiedemann syndrome.
- More than half of babies with omphalocele have abnormalities of other organs or body parts, most commonly the spine, digestive system, heart, urinary system, and limbs.
How often does an omphalocele occur?
A “small” type omphalocele (involving protrusion of a small portion of the intestine only) occurs in one out of every 5,000 live births.
A “large” type omphalocele (involving protrusion of the intestines, liver, and other organs) occurs in one out of every 10,000 live births.
More boys than girls are affected with omphalocele. Source: University of Virginia Health System
The diagnosis of an omphalocele may take place during an ultrasound while the mother is still pregnant. A recent study found that 75% of omphaloceles were diagnosed by ultrasound, most commonly between weeks 12 to 18 of pregnancy. To avoid any injury or rupture to the omphalocele sac, a cesarean birth may be performed so that the infant does not travel through the birth canal. If the omphalocele has not been detected prior to birth, it is immediately noticeable upon birth.
Infants with fetal omphalocele may experience GI tract problems such as feeding difficulties, bowel obstruction and gastroesophageal reflux. (GERD)
During the stay in the Newborn/Infant Center, a specialized team of surgeons, nurses, speech therapists (for feeding therapy) lactation consultants, respiratory therapists and social workers are available as needed. It is strongly encouraged that parent participation is active in the care of the infant.
When the infant can tolerate full feedings via oral and NG or NJ feeds and demonstrates adequate weight gain, he or she is ready to go home. Prior to discharge, teaching of special feeding techniques or other specialized care should be provided to parents by the nursing staff. The length of stay in the hospital varies from infant to infant, depending on the above outlined factors.
Approximately 25 – 40% of infants with an omphalocele have other birth defects. They may include genetic problems (chromosomal abnormalities), congenital diaphragmatic hernia, and heart defects.