Gastroschisis is a type of abominal wall defect in which the intestines and sometimes other organs develop outside the fetal abdomen through an opening in the abdominal wall. This defect is the result of obstruction of the omphalomesenteric vessels during development. It is often detected through AFP screening or a detailed fetal ultrasound. Gastroschisis is also called paraomphalocele, laparoschisis, or abdominoschisis. Omphalocele is a similar birth defect, but it involves the umbilical cord, and the organs are enclosed in a membranous sac instead of directly in the amniotic fluid.