Microstructural observations of villous and membrane histology in monochorionic triplet placenta after in vitro fertilization.

The frequency of triplet gestation is low in humans, estimated at 1:6400 deliveries. Monochorionic gestations represent a subpopulation of approximately 10% of these triplet pregnancies. Hypertensive complications are known to occur with greater frequency in the context of multiple gestation. In this report we describe microscopic placental changes associated with pre-eclampsia and proteinuria in the setting of an uncommon monochorionic-triamniotic triplet pregnancy achieved via in vitro fertilization. Histologic features observed in this case include placental stromal fibrosis and increased syncytial nodularity (Tenney-Parker change). In this triplet delivery resulting from two consecutive fissions of a single embryo, chorion and amnion configuration are also characterized with a review of the literature discussing the potential relationship between in vitro culture conditions and monozygotic multiple gestation.