What is Omphalocele?
Omphalocele is a rare condition where the patient has congenital or birth defect of the abdominal wall leading to protrusion of the patient or infant's intestines, liver and other organs outside the belly through the umbilicus or belly button. This happens due to a defect during the development of the abdominal wall muscles. A thin, transparent sac covers the protruded organs. This sac is rarely broken or open. Omphalocele is also known as exomphalos.
During the development of the baby in the six through ten weeks of pregnancy, the intestines increase in length and get pushed out into the umbilical cord, from the belly. Normally, by the eleventh week of pregnancy, the intestines go back into the belly. When this does not happen, then it results in omphalocele. The infant can have a small omphalocele where only some of the intestines are pushed outside the abdominal wall, or it can be a large omphalocele, where many organs protrude through the abdominal wall.
An omphalocele has a high mortality rate of about 25% and is also associated with severe malformations, such as neural tube defect, cardiac anomalies and chromosomal abnormalities along with congenital abnormalities. As the abdominal organs are pushed outside the abdominal wall, infants with omphalocele also tend to have other problems. The normal abdominal cavity, which contains these organs, may not grow to its normal size. Omphalocele also carries a risk of infection, especially if the sac which contains the protruded organs breaks. In some cases, there can be twisting or pinching of the organs, which can result in restricted blood flow resulting in damage to the organ.
Signs & Symptoms of Omphalocele
The sac that contains the protruded organs forms from outpouching of the peritoneum and it protrudes through the umbilicus, in the midline region. It is normal until the tenth week of pregnancy for the intestines to protrude from the abdominal wall into the umbilical cord after which they return back inside the abdomen of the fetus. Surgery is needed in severe cases of omphalocele as the abdomen of the infant is abnormally small, as it fails to expand from not accommodating the developing abdominal organs. There is a higher risk of cardiac defects with larger omphalocele.
Causes & Risk Factors of Omphalocele
In most of the cases, the cause of omphalocele is not known. Omphalocele can be caused from malrotation of the intestines when they are returning back to the abdomen during the development phase in the pregnancy. Genetic disorders, such as Patau Syndrome or Edward's syndrome are also thought to cause omphalocele. Omphalocele is also associated with Beckwith-Wiedemann syndrome.
Omphalocele can also occur from a combination of genes and other factors including the mother coming in contact with some unfavorable environment or due to consumption of certain food or drinks, or medicines during her pregnancy. If the mother consumes alcohol or is a tobacco user during pregnancy, then it increases the risk of the baby having omphalocele. Use of certain medications, such as selective serotonin-reuptake inhibitors (SSRIs), during pregnancy also increases the chances of having a baby with an omphalocele. Being overweight or obese before pregnancy increases the risk of the baby having omphalocele.
Diagnosis of Omphalocele
Diagnosis of omphalocele can be made during pregnancy or after the birth of the baby.
During Pregnancy: Prenatal tests or screening tests can be done during pregnancy to look for birth defects and other associated conditions. An omphalocele can be detected during an ultrasound or it can cause an abnormal result on a serum or blood screening test.
After the birth of the infant: Sometimes, an omphalocele can only be diagnosed after the birth of the baby when it can be clearly visualized.
Treatment for Omphalocele
Treatment for omphalocele depends on various factors, which include:
- The size of the omphalocele.
- Whether the infant has chromosomal abnormalities and other birth defects.
- The gestational age of the baby.
If the omphalocele is small in size where only a part of the intestines is present outside the belly, then surgery is often done immediately after birth to push back the intestines into the abdomen and the opening is closed. If the size of the omphalocele is large where there are many abdominal organs protruding out of the belly, then the omphalocele is repaired in stages. The doctor may cover the exposed abdominal organs using a special material and gradually, over a period of time, the organs are pushed back into the belly. After all the organs have been replaced into the belly, the opening is then closed.