Disparities in Mortality Among High Risk Pregnant Women in Illinois: A Population Based Study DEBORAH ROSENBERG, PHD, STACIE E. GELLER, PHD, LAURA STUDEE, MPH, AND SUZANNE M. COX, MPH PURPOSE: Researchers are increasingly studying maternal mortality in the context of maternal morbidity in order to identify risk and protective factors operating at each point along the morbidity-mortality continuum. This study examined factors associated with mortality in pregnant women with severe morbidity. In particular, the Black-White disparity was examined. METHODS: Illinois vital records data were linked to identify maternal deaths and other pregnant women with severe morbidity. Pregnancy-related deaths and high risk survivors were compared and case fatality rates were computed. Condition-specific and multivariable analyses were conducted, and time of death was examined. RESULTS: The overall risk of maternal death was 37.1 per 10,000 high risk pregnant women in Illinois from 1994 to 1998. Women who were older, African American, unmarried, or living in Chicago were at elevated risk of death. The adjusted relative risk for the Black-White disparity was 3.7 among all high risk pregnant women and 8.5 among women with hypertensive disorders. A greater proportion of African American and Hispanic women died within 7 days of delivery compared to White women. CONCLUSIONS: Medical risk status alone cannot explain disparities in maternal mortality. The Black- White disparity for risk of death persisted in both overall and condition-specific analyses. Ann Epidemiol 2006;16:26–32. Ó 2006 Elsevier Inc. All rights reserved. KEY WORDS: Maternal Mortality, African American, Data Linkage, Vital Statistics. INTRODUCTION Although the maternal mortality ratio (MMR) decreased from more than 800 deaths per 100,000 live births in 1900 to 7.1 deaths per 100,000 live births in 1998, there has been no appreciable change over the last 25 years (1–3). One response at the national level has been the implementation by the Centers for Disease Control and Prevention (CDC) of the Pregnancy Mortality Surveillance System (PMSS). The PMSS captures all pregnancy-related deaths in the United States (deaths within one year of pregnancy with a cause of death in the International Classification of Diseases [ICD-9] range 630–676) and allows for the dissemination of information about factors that might lead to state and national prevention strategies (4, 5). This effort by the CDC is important not only for improving case ascertainment, but also for drawing attention to the complex nature of a pregnancy-related maternal death. In addition, many states have added a field for recent pregnancy on the death certificate (typically a check box), leading to increased identification of maternal deaths, the majority of which are pregnancy-related (6, 7). Some states have also linked death certificates of reproductive age women to fetal death/live birth certificates to enhance case ascertainment and to lay the groundwork for incorporating data from the fetal death/live birth certificates into analysis of maternal death. Moreover, record linkage promotes ascertainment of pregnancy-associated deaths (deaths within 1 year of pregnancy from any cause, including those unrelated to pregnancy), which broadens the scope of maternal mortality surveillance (8–10). The CDC has also begun to stress the importance of studying maternal mortality in the context of maternal morbidity and has worked to define maternal morbidity and measure its prevalence (11). Danel and colleagues found that 1.7 million women (43% of deliveries annually) experienced some type of morbidity during the delivery hospitalization (obstetric complications, preexisting medi- cal conditions, and cesarean delivery) (12). Given this, researchers are increasingly framing studies in terms of the From the Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago (D.R.); and Department of Obstetrics and Gynecology, College of Medicine, University of Illinois at Chicago (S.E.G., L.S., S.M.C.). Address correspondence to Deborah Rosenberg, Ph.D., Research Assistant Professor, Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St., M/C 923, Chicago IL 60612. Tel.: (312) 996-5953; fax: (312) 996-0064. E-mail: drose@uic.edu This work was supported by the Centers for Disease Control and Prevention and the Association of Schools of Public Health ‘‘Investigation of Factors Associated with Maternal Mortality’’ (S1069/19-20). Received September 20, 2004; accepted April 26, 2005. Ó 2006 Elsevier Inc. All rights reserved. 1047-2797/06/$–see front matter 360 Park Avenue South, New York, NY 10010 doi:10.1016/j.annepidem.2005.04.007