Pregnancy outcomes in correlation with placental histopathology in subsequent pregnancies complicated by fetal growth restriction

Objective: In attempt to shed new light on the etiopathogenesis of fetal growth restriction (FGR) we aimed to compare pregnancy outcomes and placental histopathology in cases of first vs. subsequent FGR occurrence. Study design: Pregnancy and placental reports of FGR pregnancies (defined by birth weight < 10th percentile), born between 2008 and 2018 were reviewed. Included only cases with recurrent FGR, in two consecutive pregnancies, thus each subject served as her own control in two FGRs consecutive pregnancies. Neonatal outcome and placental histopathology were compared between the first FGR delivery (first FGR group) and the subsequent FGR delivery (subsequent FGR group). Composite adverse neonatal outcome was defined as one or more early neonatal complications. Results: Included in the study a total of 96 cases with recurrence of FGR pregnancies. Placentas from the first FGR group were characterized by higher rate of maternal vascular malperfusion (MVM) lesions as compared with the subsequent FGR group (71.8% versus 55.2%, respectively, p = 0.02). Adverse neonatal outcome was more prevalent in the first FGR group as compared to the recurrent FGR group (41.6% versus 25%, respectively, p = 0.02). After controlling for confounders, using multivariate regression analysis, placental MVM lesions (aOR = 1.36, 95% CI = 1.12-1.45) and composite adverse neonatal outcome (aOR = 1.18 95% CI = 1.09-1.55) were found to be independently associated with the first FGR group. Conclusion: First event of FGR is associated with a higher rate of placental MVM lesions and adverse neonatal outcome as compared to FGR in subsequent pregnancies.