Abstract
Objective Placenta previa and prior cesarean delivery are known risk factors for placenta accreta.
However, other risk factors have not been identified. Our objective was to examine
risk factors for accreta using data collected prospectively in a large multicenter
cohort.
Study Design Secondary analysis of women with accreta compared to those without accreta in a large
multicenter cesarean delivery cohort. Potential accreta risk factors were examined
by univariate and multivariate analyses.
Results In this study, 196 of 73,257 (0.27%) cesarean deliveries were complicated by accreta.
As expected, women with increasing numbers of prior cesareans were more likely to
have an accreta (p < 0.001), as were women with previa (adjusted odds ratio [OR], 34.9; 95% confidence
interval [CI], 22.4–54.3). We also considered only patients with previa and examined
the following variables: maternal demographics, prior cesareans, interval between
deliveries, parity, body mass index, tobacco use, and coexisting hypertension or diabetes.
In this model, patients with previa and two or three prior cesarean deliveries had
an adjusted OR for accreta of 4.9 (95% CI, 1.7–14.3) or 7.7 (95% CI, 2.4–24.9), respectively.
However, no other variables were significantly associated with accreta.
Conclusion Patients with previa have increased risk for accreta that increases with the number
of prior cesarean deliveries. However, no other maternal characteristics were associated
with accreta.
Keywords
placenta accreta - cesarean delivery - placenta previa - risk factors
