title: The association of maternal race and ethnicity and the risk of postpartum hemorrhage.
abstract: BACKGROUND
  There are profound racial and ethnic disparities in obstetric outcomes in the United States, but little is known about disparities in risk of postpartum hemorrhage (PPH). We explored the association of race and ethnicity on the risk of PPH due to uterine atony with sequential adjustment for possible mediating factors.
  
  
  METHODS
  This analysis was based on the Nationwide Inpatient Sample, from between 2005 and 2008. The frequencies of atonic PPH and atonic PPH resulting in transfusion or hysterectomy were estimated. We developed multivariable logistic regression models to estimate the odds of these outcomes in maternal racial/ethnic groups by sequentially adding potential mediators.
  
  
  RESULTS
  Hispanic ethnicity and Asian/Pacific Islander race were associated with a statistically significant increased odds of atonic PPH in comparison with Caucasians, despite adjustment for potential mediators (adjusted odds ratio [OR] for Hispanics: 1.21, 99% confidence interval [1.18, 1.25]; for Asians/Pacific Islanders: 1.31 [1.25, 1.38], with Caucasians as reference). Similar results were observed for these racial/ethnic groups for atonic PPH resulting in transfusion or hysterectomy.
  
  
  CONCLUSIONS
  Hispanic ethnicity and Asian/Pacific Islander race are significant risk factors for atonic PPH independent of measured potential mediators; biological differences may play a role.
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Bryant
authors.forename: Jill M
authors.initials: JM
authors.lastname: Mhyre
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Leffert
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Hoban
authors.forename: Mohammad Y
authors.initials: MY
authors.lastname: Yakoob
authors.forename: Brian T
authors.initials: BT
authors.lastname: Bateman
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005006:Ethnicity / Q000208:ethnology / Q000235:genetics; D005260:Female; D006801:Humans; D008875:Middle Aged; D006473:Postpartum Hemorrhage / Q000208:ethnology* / Q000209:etiology / Q000235:genetics*; D011247:Pregnancy; D044469:Racial Groups / Q000208:ethnology / Q000235:genetics; D012307:Risk Factors; D055815:Young Adult