Intrauterine death of co-twin in the third trimester: a case report of twin-to-twin transfusion syndrome and cord accident.

Intrauterine death of one twin in a monochorionic twin pregnancy is associated with increased mortality and morbidity of the survivor. The exact cause is usually difficult to determine even after delivery. The choice of management for the mother and the viable co-twin is difficult. We report on a case of intrauterine death of one twin with monochorionic placentation. Twin-to-twin transfusion syndrome was suggested by the sonographic findings and evidence of a vascular communication. The co-twin survived for another 39 days without complications after the diagnosis of fetal death. Postmortem examination showed severe torsion and constriction of the umbilical cord at the fetal end with focal deficiency of Wharton's jelly. It is likely that torsion and constriction of the cord was responsible for the one intrauterine fetal death; this so-called "twist amputation" of the cord, on the other hand, contributed to the favorable outcome in the surviving co-twin.