Study finds abnormal fetal circulation as a risk factor for fetal thrombotic vasculopathy

Examination of the placenta can offer answers to the questions that arise following an adverse perinatal outcome, such as stillbirth or intrauterine growth restriction. A placental lesion known as fetal thrombotic vasculopathy (FTV) has been associated with a number of adverse outcomes. By studying placentas with this lesion, researchers hope to determine the risks of such serious complications that affect fetuses and newborns.

The November 2010 issue of the journal Pediatric and Developmental Pathology presents the results of a pathologic study of placentas with FTV and a control group without the lesion. Researchers sought to determine the prevalence of obstetric complications as well as adverse outcomes in the immediate neonatal period as they relate to placentas with FTV.

Electronic medical records and pathology reports from an 18-year period were used to extract information about more than 300 cases. These details included maternal and gestational age, method of delivery, neonatal outcome (live birth, stillbirth, or neonatal death), lesions of the umbilical cord, obstetric complications, and fetal abnormalities. The authors examined placental slides of all cases.

The study found that patients in the FTV group differed from those in the control group in that they were older, had a higher rate of cesarean delivery, were more likely to have a preterm birth, and had a higher rate of obstetric complications. Additionally, FTV placentas were significantly smaller than the control placentas.

Fortunately, it is a rare condition; however, the presence of FTV in the placenta greatly increases the risk of an adverse outcome for the fetus or newborn. This study found a ninefold increase in the rate of stillbirth and a twofold increase in intrauterine growth restriction. A sixfold increase was documented for both oligohydramnios—a deficiency of amniotic fluid—and fetal cardiac abnormalities.

An association between FTV and obstructive umbilical cord lesions was also found. The authors find that 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."