First-birth cesarean and placental abruption or previa at second birth

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 usi ng data from the Washington State Birth Events Record Database. The study c ohort included all primiparas who gave birth to live singleton infants in n onfederal short-stay hospitals from January 1, 1987, through December 31, 1 996, 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 10 00 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 se cond births, compared with women with prior vaginal deliveries. Conclusion: We found moderately increased risk of placental abruption and p revia as a long-term effect of prior cesarean delivery on second births. (O bstet Gynecol 2001;97: 765-9. (C) 2001 by The American College of Obstetric ians and Gynecologists.).