Obstetric and perinatal complications in placentas with fetal thrombotic vasculopathy

Fetal thrombotic vasculopathy (FTV) is a placental lesion characterized by regionally distributed avascular villi and is often accompanied by upstream thrombosis in placental fetal vessels. Previous studies, using preselected populations, have shown associations of this lesion with adverse neurodevelopmental outcomes and potentially obstructive lesions of the umbilical cord. We investigated the prevalence of obstetric complications, perinatal disease, and placental abnormalities in cases with FTV. One hundred thirteen cases of placentas with FTV were identified in our pathology database over an 18-year period. Two hundred sixteen placentas without the diagnosis of FTV, frequency matched on year of birth, were selected as controls. Electronic medical records and pathology reports were used to extract maternal and gestational age, method of delivery, neonatal outcome, lesions of the umbilical cord, obstetric complications, and fetal abnormalities. Placentas with FTV were associated with a 9-fold increase in rate of stillbirth and a 2-fold increase in intrauterine growth restriction. The increase in pregnancy-induced hypertension/preeclampsia was not significant when adjusted for maternal and gestational age. Although the rate of potentially obstructive cord lesions was similar in both groups, there was an almost 6-fold increase in the presence of oligohydramnios in FTV placentas, compared with controls. Finally, FTV was associated with a 6-fold increase in fetal cardiac abnormalities. Fetal thrombotic vasculopathy is associated with a significantly higher rate of obstetric and perinatal complications. This study points to abnormal fetal circulation, either in the form of congenital heart disease or oligohydramnios predisposing to cord compression, as a risk factor for FTV.