Unilateral ischemia of the fused twin placenta: a manifestation of the twin transfusion syndrome?

Two cases of multiple births were observed in which a twin placenta showed a striking gross and microscopic ischemia of one of its fused components. In both cases death of one or more of the infants occurred. Case 1 was a triplet birth of identical siblings and two of the infants died on the second and third days after birth, respectively. Case 2 was a twin birth in which one of the infants was stillborn. Two other cases are quoted from the literature in which a similar pallor of one-half of the twin placenta was observed, and both these cases were also associated with death of the associated fetus.It is possible that this placental lesion may be due to transfusion of blood from one placental half to the other (twin transfusion syndrome) with harmful effects on one or both fetuses.