title: Risk factors for placenta accreta: a large prospective cohort.
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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Obstetrics and Gynecology, University of Utah Health Sciences Center and Intermountain Healthcare, Salt Lake City, Utah.
authors: Zachary S
authors: ZS
authors: Bowman
authors: Department of Obstetrics and Gynecology, University of Utah Health Sciences Center and Intermountain Healthcare, Salt Lake City, Utah.
authors: Alexandra G
authors: AG
authors: Eller
authors: Division of Epidemiology, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah.
authors: Tyler R
authors: TR
authors: Bardsley
authors: Division of Epidemiology, Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah.
authors: Tom
authors: T
authors: Greene
authors: Department of Obstetrics and Gynecology, University of Utah Health Sciences Center and Intermountain Healthcare, Salt Lake City, Utah.
authors: Michael W
authors: MW
authors: Varner
authors: Department of Obstetrics and Gynecology, University of Utah Health Sciences Center and Intermountain Healthcare, Salt Lake City, Utah.
authors: Robert M
authors: RM
authors: Silver
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects*; D005260:Female; D006801:Humans; D010921:Placenta Accreta / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D010923:Placenta Previa / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult