Omphalocele is a congenital abdominal wall defect. The abdominal wall remains open, and the intestines and abdominal organs are covered by the amniotic sac. During fetal development between weeks 6 and 10 of pregnancy, the intestines elongate and herniate into the umbilical cord. Normally, by week 11, the intestines return to the abdomen. Failure of the intestines to return results in omphalocele. In omphalocele, some of the intestines may remain outside the abdomen, and other internal organs may also protrude alongside the intestines.