Constriction of the umbilical cord leading to fetal death. A report of three cases.

Constriction of the umbilical cord is characterized by localized absence of Wharton's jelly, leading to narrowing of the cord, thickening of the vascular walls and narrowing of the vascular lumens. This may result in a compromised fetal blood supply, leading to fetal anoxia and eventual fetal death. Approximately 50 cases have been reported in the world literature over the last three centuries. Three cases of umbilical cord constriction leading to intrauterine fetal demise are reported. Two of the patients presented during the late second trimester with loss of sensation of fetal movements. Intrauterine fetal demise was diagnosed, and autopsy revealed constricted umbilical cords associated with torsion. The third patient is unique in that fetal death was precipitated by a routine, technically uncomplicated, transplacental amniocentesis procedure performed in the early second trimester. At the time of termination of the pregnancy we found marked stenosis with torsion over a 1-cm segment of the umbilical cord juxtaposed against the fetal insertion site. Umbilical cord constriction is a rare, almost invariably fatal condition, usually undiagnosed antenatally. In case 3, disruption of the placenta by amniocentesis may have initiated a terminal event in a fetus already compromised by a cord constriction. Three possible mechanisms could have contributed to the fetal death after amniocentesis in the presence of cord constriction: acute vasospasm, acute oligohydramnios and uterine contraction, or an obliterating thrombus.