Umbilical cord disruption sequence caused by long cord in two unrelated infants with amyoplasia.

Encirclement of a fetal body part by the umbilical cord with or without vascular obstruction in either the umbilical cord or the encircled fetal part is considered an umbilical cord loop (UCL). Significant disruption of the encircled fetal parts is recognized as the umbilical cord disruption sequence (UCDS). UCL around fetal parts is an occasional anomaly in infants with amyoplasia. We report on 2 patients with amyoplasia and damage to the fetal limbs caused by UCDS and a long umbilical cord. Patient 1 showed two deep constrictions on the left lower limb caused by UCL with an intact skin and a mild mark of constriction on the left wrist. The umbilical cord in patient 2 produced 5 entanglements around the left thigh which resulted in a deep groove extending down to the femur and also showed an exposed fracture and gangrene of the entire lower limb with an unusual congenital paraumbilical "stoma" that corresponded to the afferent loops of a jejunal atresia. The UCDS in infants with amyoplasia has been associated with short umbilical cords, whereas in patients without congenital contractures, the UCDS or UCL has been related to long umbilical cords. Our observations of UCDS in patients with amyoplasia but with long umbilical cords suggest the influence of both pathogenic factors or the existence of additional mechanisms. Evidence in patient 2 may support a vascular pathogenesis.