Constriction of the umbilical cord by an amniotic band after midtrimester amniocentesis.

Constriction of the umbilical cord by an amniotic band after previous midtrimester amniocentesis is an extremely rare entity. A case report of fetal asphyxia caused by partial occlusion of the umbilical cord by an amniotic band is presented. Clinical and experimental evidence strongly suggests that the pathogenesis of this defect is related to early rupture of the membranes during gestation with subsequent encirclement and ligation of fetal umbilical cord, or extremities. In this case, formation of the amniotic band caused by midtrimester amniocentesis is strongly suggested. Obstetricians should be aware of this hazardous complication during pregnancy and labor in women who had had a midtrimester amniocentesis.