GASTROSCHISIS OMPHALOCELE CAUSES

Causes:
• Factors associated with high-risk pregnancies, such as maternal illness and infection, drug use, smoking, and genetic abnormalities, also are associated with the birth of babies with omphalocele and gastroschisis. These factors contribute to placental insufficiency and the birth of small for gestational age (SGA) or premature babies, among whom gastroschisis and omphalocele most commonly occur.

• Folic acid deficiency, hypoxia, and salicylates have caused laboratory rats to develop abdominal wall defects, but the clinical significance of these experiments is conjectural. Certainly, elevation of maternal serum alpha-fetoprotein (MSAFP) warrants investigation by high-resolution sonography to determine if any structural abnormalities are present in the fetus. If such abnormalities are present and associated with an omphalocele, perform amniocentesis to check for a genetic abnormality.

• Polyhydramnios suggests fetal intestinal atresia, and this possibility should be investigated by ultrasound. Ideally, such information will prompt referral to a tertiary care facility, where the infant can receive expeditious specialty care.

Lab Studies:
• Maternal serum alpha-fetoprotein
o Prenatal diagnosis of abdominal wall defects can be made by detection of an elevation in MSAPF.
o MSAPF levels are greater in gastroschisis than in omphalocele
o MSAPF also is increased in spina bifida, which additionally demonstrates an increased ratio of acetylcholinesterase and pseudocholinesterase.

Imaging Studies:
• Fetal sonography may detect a genetic abnormality, with identification of a structural marker of the karyotypic abnormality.
• Fetal echocardiography also may identify a cardiac abnormality.
• Confirm positive findings suggestive of a genetic abnormality by amniocentesis.
• If serial ultrasounds show dilatation and thickening of the intestine in a baby with gastroschisis, and if lung maturity can be verified by amniocentesis, delivery is induced.