Racial and ethnic differences in the prevalence of placenta previa

Objective:the objective of this study is to determine the prevalence of placenta previa among different racial and ethnic groups.study design:we conducted a retrospective cohort study to examine the prevalence of placenta previa among five major racial and ethnic groups: african american, asian, caucasian, hispanic and native american. we included all deliveries ⩾20 weeks gestation from a large northern californian health maintenance organization from 1995–2006. a multivariable logistic regression model was used to control for potential confounders.result:of the 394 083 deliveries in our cohort, 1580 (0.40%) were complicated by placenta previa. the prevalence of placenta previa was: asian 0.64%, native american 0.60%, african american 0.44%, caucasian 0.36%, hispanic 0.34% and unknown 0.31% (p<0.001). in our multivariable logistic regression model, only asians (odds ratio (or) 1.73, 95% confidence intervals (ci) 1.53–1.95) and african americans (or 1.43, 95% ci 1.19–1.72) were at increased risk for having placenta previa, compared with caucasians.conclusion:asian women have the highest prevalence of placenta previa.