Newborns can be born with abdominal wall defects, conditions where the abdominal organs develop outside the body. These conditions arise early in pregnancy when the abdominal wall does not form completely. Among these, omphalocele and gastroschisis are two distinct types that affect how the organs are positioned at birth. Understanding these differences is important for parents and caregivers.
Understanding Omphalocele
Omphalocele is a birth defect where a baby’s abdominal organs protrude through an opening at the belly button. These organs, which can include the intestines, liver, and sometimes the stomach, are contained within a thin, translucent sac. This sac, formed from the peritoneum, is intact at birth, protecting the exposed organs.
This condition occurs during early fetal development, between 6 and 11 weeks of pregnancy. The intestines normally bulge into the umbilical cord as they grow, returning to the abdomen by the 11th week. An omphalocele develops if this return does not happen. The defect’s size varies, from a small portion of the intestine to most abdominal organs, including the liver, protruding outside the body. Babies born with an omphalocele have other congenital anomalies, such as heart defects, neural tube defects, or chromosomal abnormalities like Trisomy 18 or Beckwith-Wiedemann syndrome.
Understanding Gastroschisis
Gastroschisis is a birth defect characterized by a hole in the abdominal wall, located to the right of the umbilical cord. Through this opening, the baby’s intestines, and sometimes other organs like the stomach, protrude outside the body. Unlike omphalocele, there is no protective sac covering these exposed organs.
The organs float freely in the amniotic fluid within the uterus, which can lead to irritation, swelling, and potential damage or shortening of the intestines. This condition also develops early in pregnancy, between the fourth and eighth weeks, due to a weakness in the abdominal wall muscles near the umbilical cord. Gastroschisis is less associated with other congenital anomalies compared to omphalocele, although complications like intestinal atresia (a blockage or incomplete formation of the intestine) can occur.
How They Differ
The primary distinctions between omphalocele and gastroschisis lie in the location of the defect, the presence of a protective sac, and the types of organs involved. In omphalocele, the opening is directly at the umbilical cord, and the protruding organs are encased in a transparent membrane. This sac provides a barrier, reducing direct exposure to amniotic fluid. In contrast, gastroschisis presents as an opening to the right of the umbilical cord, and the exposed organs lack any covering membrane, making them vulnerable to the amniotic fluid.
Regarding the organs involved, omphalocele can include a broader range, such as intestines, liver, and stomach, reflecting a more central failure of abdominal wall closure. Gastroschisis, however, involves only the intestines protruding through the defect. Another difference is the association with other birth defects. Omphalocele has a higher incidence of co-occurring anomalies, including heart defects and chromosomal abnormalities, affecting more than half of infants born with the condition. Gastroschisis is an isolated defect, with other birth defects being less common.
Diagnosis and Initial Care
Both omphalocele and gastroschisis are diagnosed before birth through routine prenatal ultrasound examinations during the second or third trimester of pregnancy. An ultrasound can reveal the abnormal positioning of the organs, and further tests like a fetal echocardiogram may be conducted to check for associated heart defects, particularly in cases of omphalocele. Early diagnosis allows medical teams to prepare for specialized care immediately after birth.
Upon delivery, immediate steps are taken to protect the exposed organs. For both conditions, maintaining the baby’s body temperature is important, as exposed organs can lead to heat loss. The protruding organs are covered with sterile, moist dressings or placed into a protective plastic bag or a “silo” to prevent fluid loss and infection.
Intravenous fluids are administered to provide hydration and nutrients, since the baby cannot feed normally right away. Surgical repair is necessary, and the approach depends on the defect’s size and complexity. For smaller defects, primary closure may be possible, where the organs are gently placed back into the abdomen and the opening is closed in a single surgery. Larger defects require a staged repair, where the organs are gradually returned to the abdominal cavity over days or weeks using a silo device, allowing the abdomen to expand before final closure.