title: Investigating racial differences in risk factors for primary cesarean delivery.
abstract: OBJECTIVE
  The objective of the study was to investigate differences in sociodemographic, medical, and obstetric risk factors for primary cesarean delivery between black and white women.
  
  
  METHODS
  We conducted a retrospective cohort study among 25,251 black and white women delivering a live, singleton infant with vertex presentation at a large, regional hospital between 2004 and 2010. Demographic and clinical data were derived from electronic hospital records. Differences in risk factors for primary cesarean delivery were analyzed using a modified Poisson regression approach stratified by race and parity.
  
  
  RESULTS
  Black and white women had a primary cesarean delivery rate of 24.7% and 22.2%, respectively (P < .001). Black women had an increased risk of cesarean delivery after adjusting for sociodemographic and clinical risk factors (adjusted relative risk [RR], 1.23; 95% confidence interval [CI], 1.17-1.29). Among nulliparas, labor induction had a greater effect on cesarean delivery for black women (adjusted RR, 1.32; 95% CI, 1.20-1.44) than for white women (adjusted RR, 1.13; 95% CI, 1.07-1.20). Among multiparas, labor induction reduced the risk of cesarean delivery for white women (adjusted RR, 0.63; 95% CI, 0.55-0.72), whereas no association was observed for black women (adjusted RR, 1.08; 95% CI, 0.92-1.28). Advanced maternal age was a stronger risk factor for black women (adjusted RR, 1.72; 95% CI, 1.43-2.08) than for white women (adjusted RR, 1.30; 95% CI, 1.11-1.52) among multiparas only. Among nulliparas, delivery at 37-38 weeks' gestation reduced the risk of cesarean delivery for black women (adjusted RR, 0.82; 95% CI, 0.73-0.92), whereas no association was observed for white women (adjusted RR, 0.96; 95% CI, 0.90-1.04).
  
  
  CONCLUSIONS
  Labor induction, among nulliparous women, and advanced maternal age, among multiparous women, are stronger risk factors for primary cesarean delivery for black women than for white women.
authors: Department of Population, Family, and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD. Electronic address: cmin4@jhu.edu.
authors: Caroline J
authors: CJ
authors: Min
authors: Department of Obstetrics and Gynecology, Christiana Care Health System, Newark, DE.
authors: Deborah B
authors: DB
authors: Ehrenthal
authors: Department of Population, Family, and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
authors: Donna M
authors: DM
authors: Strobino
mesh_terms: D000328:Adult; D001741:Black or African American; D002585:Cesarean Section / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D044465:White People; D055815:Young Adult
keywords: advanced maternal age; cesarean delivery; labor induction; racial disparities