803 Short interpregnancy interval and placenta accreta spectrum

Abstract

We aimed to investigate the association between short interpregnancy interval (IPI) and placenta accreta spectrum (PAS). A cohort study of patients at risk for PAS evaluated at a tertiary care center between 1999 and 2020. Our cohort was defined as women at risk for PAS defined as multiple prior cesarean deliveries and/or placenta previa. The primary outcome was histopathologically- or surgically- confirmed PAS. Short IPI was defined as less than 18 months from previous delivery and last menstrual period of the index pregnancy. Chi-squared, univariate, and multivariate logistic regression models were used to calculate the unadjusted and adjusted odds ratios for the association of short IPI and PAS. Covariates were selected by p<0.2 or if deemed clinically significant. The final model was derived by reverse stepwise selection of variables. Of 262 patients at-risk of PAS, 112 (42%) had PAS. Groups defined by short IPI differed by several maternal and obstetrical characteristics (Table 1). 49% (39/80) of women with short IPI had PAS, compared to 40% (73/182) of women with optimal IPI. Short IPI was not associated with PAS (OR 1.06; 95% confidence interval [CI], 0.62-1.80; adjusted OR 1.04; 95% CI, 0.51-2.15)(Table 2). In patients with prior multiple prior cesarean deliveries and/or previa, short IPIl was not associated with PAS. Our study suggests that short IPI is not likely an important modifiable risk factor for PAS.View Large Image Figure ViewerDownload Hi-res image Download (PPT)