Objective: To ascertain the impact of placental architecture on antenatal course and labor delivery in a low-risk primigravid population.
Methods: This study involves prospective recruitment of 1011 low-risk primigravids with placental ultrasound at 22?24 weeks and 36 weeks. Detailed postnatal review of all mothers and infants was undertaken. Retrospective analysis of ultrasound and clinical outcome data was performed.
Results: Eight hundred ten women with complete outcome data were available. Anterior placentation was statistically associated with intrauterine growth restriction (IUGR) and preterm birth and fundal placentation was significantly associated with a higher incidence of pregnancy-induced hypertension and infants with a birthweight less than the 9th centile. Placental infarcts in the third trimester was significantly increased in cases complicated by pre-eclampsia (PET) and in cases with fetal acidosis. Placental calcification was associated a 40-fold increase in the incidence of IUGR. Placental lakes in the second trimester were more prevalent in patients with threatened miscarriage. Increased placental thickness was associated with a higher rate of fetal acidosis. The Grannum grade of the placenta was higher with threatened first or second trimester loss, PET and in infants born less than 9th centile for gestation.
Conclusion: Placental site and architecture impact on the incidence of maternal and fetal disease.