Placental Lesions and Pregnancy Outcome in Anterior as Compared to Posterior Placenta Previa

The uterine location of placenta previa (PP), anterior vs. posterior has an impact on pregnancy outcome. We aimed to study maternal and neonatal outcome and placental histopathology lesions in anterior vs. posterior PP. The medical records and histopathology reports of all singleton cesarean deliveries (CD) performed due to PP, from 24 to 41 weeks, between 12.2008 and 10.2018, were reviewed. Placental lesions were classified into maternal and fetal vascular malperfusion lesions (MVM, FVM), maternal and fetal inflammatory responses (MIR, FIR). Gestational age (GA) at delivery was similar between the anterior PP (n = 67) and posterior PP (n = 105) groups. As compared to the posterior PP group, the anterior PP group had higher rate of previous CD (p < 0.001), placental accreta spectrum (p = 0.04), lower neonatal Hb at birth (p = 0.03), higher rate of neonatal blood transfusion (p = 0.007) and prolonged maternal hospitalization (p = 0.02). Placentas from the anterior PP group had lower weights (p = 0.035), with increased rate of MVM lesions (p = 0.017). The anterior PP location is associated with increased adverse maternal and neonatal outcome, lower placental weights and increased rate of malperfusion lesions. Abnormal placentation in the scarred uterine wall probably has an impact on placental function.