The Association of Maternal Race and Ethnicity and the Risk of Postpartum Hemorrhage

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. CONCLUSION: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.

[1]  Samuel F. Posner,et al.  An Enhanced Method for Identifying Obstetric Deliveries: Implications for Estimating Maternal Morbidity , 2008, Maternal and Child Health Journal.

[2]  D. Seidman,et al.  Obstetric risk factors and outcome of pregnancies complicated with early postpartum hemorrhage: A population-based study , 2005, The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians.

[3]  W. Gilbert,et al.  Accuracy of obstetric diagnoses and procedures in hospital discharge data. , 2006, American journal of obstetrics and gynecology.

[4]  Aaron B Caughey,et al.  The association between the length of first stage of labor, mode of delivery, and perinatal outcomes in women undergoing induction of labor. , 2009, American journal of obstetrics and gynecology.

[5]  C. Berg,et al.  The Black–White Disparity in Pregnancy-Related Mortality From 5 Conditions: Differences in Prevalence and Case-Fatality Rates , 2007 .

[6]  M. Blomberg.  Maternal Obesity and Risk of Postpartum Hemorrhage , 2011, Obstetrics and gynecology.

[7]  Samuel Parry,et al.  A polymorphism in the promoter region of TNF and bacterial vaginosis: preliminary evidence of gene-environment interaction in the etiology of spontaneous preterm birth. , 2004, American journal of obstetrics and gynecology.

[8]  M. Bracken,et al.  Hospital volume, provider volume, and complications after childbirth in U.S. hospitals. , 2012, Obstetrics and gynecology.

[9]  M. Shriver,et al.  Genetic Contributions to Disparities in Preterm Birth , 2009, Pediatric Research.

[10]  J. Gould,et al.  Obstetric complications during labor and delivery: assessing ethnic differences in California. , 2006, Women's health issues.

[11]  Scott M. Williams,et al.  Racial disparity in maternal-fetal genetic epistasis in spontaneous preterm birth. , 2008, American journal of obstetrics and gynecology.

[12]  Chunhua Weng,et al.  Beta-2 adrenoceptor genotype and progress in term and late preterm active labor. , 2011, American journal of obstetrics and gynecology.

[13]  Jonathan M Morris,et al.  How accurate is the reporting of obstetric haemorrhage in hospital discharge data? A validation study , 2008, The Australian & New Zealand journal of obstetrics & gynaecology.

[14]  C. Combs,et al.  Factors Associated With Postpartum Hemorrhage With Vaginal Birth , 1991, Obstetrics and gynecology.

[15]  W. P. Frisbie,et al.  Racial and ethnic differences in determinants of intrauterine growth retardation and other compromised birth outcomes. , 1997, American journal of public health.

[16]  K. Gregory,et al.  Age and racial/ethnic differences in maternal, fetal, and placental conditions in laboring patients. , 2003, American journal of obstetrics and gynecology.

[17]  S. Cole,et al.  Fallibility in estimating direct effects. , 2002, International journal of epidemiology.

[18]  A. Jha,et al.  Quality of colon cancer outcomes in hospitals with a high percentage of Medicaid patients. , 2008, Journal of the American College of Surgeons.

[19]  S. Lipsitz,et al.  Do Differences in Hospital and Surgeon Quality Explain Racial Disparities in Lower-Extremity Vascular Amputations? , 2009, Annals of surgery.

[20]  P. J. Sparks.  Do biological, sociodemographic, and behavioral characteristics explain racial/ethnic disparities in preterm births? , 2009, Social science & medicine.

[21]  K. Joseph,et al.  US Black vs White disparities in foetal growth: physiological or pathological? , 2006, International journal of epidemiology.

[22]  P. Flood,et al.  Mathematical Modeling of the Pain and Progress of the First Stage of Nulliparous Labor , 2009, Anesthesiology.

[23]  H. Rockman,et al.  β-Arrestin mediates oxytocin receptor signaling, which regulates uterine contractility and cellular migration. , 2011, American journal of physiology. Endocrinology and metabolism.

[24]  F. Malone,et al.  Early Access to Prenatal Care: Implications for Racial Disparity in Perinatal Mortality , 2006, Obstetrics and gynecology.

[25]  Aaron B Caughey,et al.  Racial/ethnic disparities in obstetric outcomes and care: prevalence and determinants. , 2010, American journal of obstetrics and gynecology.

[26]  K. Kahn,et al.  Vaginal birth after cesarean and uterine rupture rates in California. , 1999, Obstetrics and gynecology.

[27]  Patrick S Romano,et al.  Coding of Perineal Lacerations and Other Complications of Obstetric Care in Hospital Discharge Data , 2005, Obstetrics and gynecology.

[28]  C. Berg,et al.  Pregnancy-Related Mortality in the United States, 1998 to 2005 , 2010, Obstetrics and gynecology.

[29]  Y. Oyelese.  Postpartum Hemorrhage: Epidemiology, Risk Factors, and Causes , 2010, Clinical obstetrics and gynecology.

[30]  Scott M. Williams,et al.  Ethnic Differences in Key Candidate Genes for Spontaneous Preterm Birth: TNF-α and Its Receptors , 2006, Human Heredity.

[31]  J. Evans,et al.  Poor uterine contractility in obese women , 2007, BJOG : an international journal of obstetrics and gynaecology.

[32]  A. Samadi,et al.  Maternal Hypertension and Associated Pregnancy Complications Among African‐American and Other Women in the united States , 1996, Obstetrics and gynecology.

[33]  D. Brennan,et al.  Identification of a myometrial molecular profile for dystocic labor , 2011, BMC pregnancy and childbirth.

[34]  T. J. Mathews,et al.  Infant mortality statistics from the 2005 period linked birth/infant death data set. , 2008, National vital statistics reports : from the Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System.

[35]  B. Sibai,et al.  The MFMU Cesarean Registry: uterine atony after primary cesarean delivery. , 2005, American journal of obstetrics and gynecology.

[36]  Motao Zhu,et al.  Racial disparity in hypertensive disorders of pregnancy in New York State: a 10-year longitudinal population-based study. , 2007, American journal of public health.

[37]  T. Gordon,et al.  Effect of Academic Affiliation and Obstetric Volume on Clinical Outcome and Cost of Childbirth , 2001, Obstetrics and gynecology.

[38]  Siobhan M. Dolan,et al.  Genetic and environmental contributions to racial disparities in preterm birth. , 2010, The Mount Sinai journal of medicine, New York.

[39]  M Joffe,et al.  Maternal obesity and pregnancy outcome: a study of 287 213 pregnancies in London , 2001, International Journal of Obesity.

[40]  W. Callaghan,et al.  The reporting of pre-existing maternal medical conditions and complications of pregnancy on birth certificates and in hospital discharge data. , 2005, American journal of obstetrics and gynecology.

[41]  M. Berman,et al.  The Epidemiology of Postpartum Hemorrhage in a Large, Nationwide Sample of Deliveries , 2010, Anesthesia and analgesia.

[42]  E. Lieberman,et al.  Patterns of Pregnancy-Related Hypertension in Black and White Women , 2005, Hypertension in pregnancy.

[43]  Scott M. Williams,et al.  Ethnic differences in key candidate genes for spontaneous preterm birth: TNF-alpha and its receptors. , 2006, Human heredity.

[44]  Jay J. Shen,et al.  Disparities in maternal outcomes among four ethnic populations. , 2005, Ethnicity & disease.

[45]  W. Callaghan,et al.  Accuracy of reporting maternal in-hospital diagnoses and intrapartum procedures in Washington State linked birth records. , 2005, Paediatric and perinatal epidemiology.

[46]  B. Mitchell,et al.  Physiological pathways and molecular mechanisms regulating uterine contractility. , 2010, Human reproduction update.

[47]  K. Schoendorf,et al.  The contribution of preterm birth to the Black-White infant mortality gap, 1990 and 2000. , 2007, American journal of public health.