First-Birth Cesarean and Placental Abruption or Previa at Second Birth

In Brief Objective To assess the association between first-birth cesarean delivery and second-birth placental abruption and previa. Methods We conducted a population-based, retrospective cohort analysis using data from the Washington State Birth Events Record Database. The study cohort included all primiparas who gave birth to live singleton infants in nonfederal short-stay hospitals from January 1, 1987, through December 31, 1996, and who had second singleton births during the same period (n = 96,975). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for placental abruption or previa at second births associated with first-birth cesareans. Results Among our study cohort, abruptio placentae complicated 11.5 per 1000 and placenta previa 5.2 per 1000 singleton deliveries at second births. In logistic regression analyses adjusted for maternal age, women with first-birth cesareans had significantly increased risk of abruptio placentae (OR 1.3, 95% CI 1.1, 1.5), and placenta previa (OR 1.4, 95% CI 1.1, 1.6) at second births, compared with women with prior vaginal deliveries. Conclusion We found moderately increased risk of placental abruption and previa as a long-term effect of prior cesarean delivery on second births. Women with first births by cesarean delivery are at only moderately increased risk of placental abruption or previa in their second births.