859: Rates of cesarean delivery after long interpregnancy intervals

Abstract

It is not known if the length of the interpregnancy interval among multiparas with a previous vaginal delivery is related to the mode of delivery with the subsequent pregnancy. We sought to examine the rate of cesarean delivery according to the length of interpregnancy intervals in this group. This was a retrospective cohort study of all women who had at least two deliveries at 23 weeks’ gestation or greater at a single academic institution. Only the second pregnancy was analyzed. Women with a history of cesarean delivery, multiple gestation, placenta previa, fetal anomaly, and stillbirth were excluded and categorized based on interpregnancy intervals (≤18 months, 19-36 months, 37-72 months, and ≥73 months). Our primary outcome was the rate of cesarean delivery. A multivariable logistic regression analysis was performed to calculate adjusted odds ratios (OR) and 95% confidence intervals (95%CI), controlling for predefined covariates (age, gestational age, race/ethnicity, and prepregnancy body mass index [kg/m2] before the first pregnancy). Of 2741 women, there were 433 (15.8%), 1191 (43.5%), 911 (33.2%), and 206 (7.5%) with interpregnancy intervals of ≤18 months, 19-36 months, 37-72 months, and ≥73 months, respectively. Rates of cesarean delivery of women relative to interpregnancy intervals of ≤18 months, 19-36 months, 37-72 months, and ≥73 months were 0.5%, 6.5%, 8.0%, and 11.2%, respectively (P =.04). Women with the longest interpregnancy intervals (≥73 months) compared to those with the shortest interpregnancy intervals ≤18 months) had higher odds of cesarean delivery (adjusted OR 2.62; 95%CI 1.33-5.15), cesarean delivery due to arrest of dilation or descent (adjusted OR 6.64; 95%CI 1.32-33.34), and cesarean delivery for non-reassuring fetal heart tracing (adjusted OR 6.22; 95%CI 2.07-18.70). In our cohort of multiparous women with a history of a prior vaginal delivery, a long interpregnancy interval ≥73 months was associated with increased odds of cesarean delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)