Race, ethnicity, and nativity differentials in pregnancy-related mortality in the United States: 1993-2006.

OBJECTIVE: To compare trends in and causes of pregnancy-related mortality by race, ethnicity, and nativity from 1993 to 2006.

METHODS: We used data from the Pregnancy Mortality Surveillance System. For each race, ethnicity, and nativity group, we calculated pregnancy-related mortality ratios and assessed causes of pregnancy-related death and the time between the end of pregnancy and death.

RESULTS: Race, ethnicity, and nativity-related minority women contributed 40.7% of all U.S. live births but 61.8% of the 7,487 pregnancy-related deaths during 1993-2006. Pregnancy-related mortality ratios were 9.1 and 7.5 deaths per 100,000 live births among U.S.- and foreign-born white women, respectively, and slightly higher at 9.6 and 11.6 deaths per 100,000 live births for U.S.- and foreign-born Hispanic women, respectively. Relative to U.S.-born white women, age-standardized pregnancy-related mortality ratios were 5.2 and 3.6 times higher among U.S.- and foreign-born black women, respectively. However, causes and timing of death within 42 days postpartum were similar for U.S.-born white and black women with cardiovascular disease, cardiomyopathy, and other pre-existing medical conditions emerging as chief contributors to mortality. Hypertensive disorders, hemorrhage, and embolism were the most important causes of pregnancy-related death for all other groups of women.

CONCLUSION: Except for foreign-born white women, all other race, ethnicity, and nativity groups were at higher risk of dying from pregnancy-related causes than U.S.-born white women after adjusting for age differences. Integration of quality-of-care aspects into hospital- and state-based maternal death reviews may help identify race, ethnicity, and nativity-specific factors for pregnancy-related mortality.

LEVEL OF EVIDENCE: III.