The impact of placental massive perivillous fibrin deposition on neonatal outcome in pregnancies complicated by fetal growth restriction

Introduction: Massive perivillous fibrin deposition (MPDD) is an uncommon placental lesion which has been associated with an increased risk of adverse pregnancy outcome in retrospective series. The purpose of the study was to evaluate the frequency and consequences of MPFD in pregnancies complicated by fetal growth restriction (FGR). Materials and methods: A cohort study of 355 pregnancies complicated by FGR diagnosed according to standard ultrasonographic criteria, enrolled, followed and delivered at a single obstetric unit. Pathological placental lesions were classified according to the Amsterdam Placental Workshop Consensus. Penalized logistic regression models were used to evaluate the association of MPFD with maternal risk factors, other pathological lesions and neonatal outcome. Results: The rates of moderate (25-50% of villi) and severe (> 50% of villi) MPFD were 8.7% (31/355) and 3.1% (11/355), respectively. Compared to other FGR cases, MPFD pregnancies were characterized by higher placental volume (450 +/- 144.5 SD as compared to 412.2 +/- 151 cm(3),p < 0.001) and lower birthweight/placental weight ratio (5.32 +/- 1.53 compared to 6.1 +/- 1.52,p < 0.001). The rates of abnormal Doppler ultrasound studies of umbilical and middle cerebral artery were similar in MPFD subjects and controls. After correction for gestational age and birthweight, MPFD was associated with an increased risk of neonatal intraventricular hemorrhage (> grade II) (OR = 5.66,95% CI = 1.69-18.97), sepsis (OR = 5.9, 95% CI = 1.27-27.12), proven necrotizing enterocolitis (OR = 9.84,95% CI = 2.49-38.8) and overall severe adverse neonatal outcome (OR = 5.71,95% CI = 2.05-15.87). Conclusions: Moderate-to-severe MPFD was relatively common among FGR pregnancies and was associated with morphometric modifications of placenta and with an increased risk of severe adverse neonatal outcome.