To quantitate the contribution of various demographic factors to the U.S. maternal mortality ratio.METHODS:
This was a retrospective observational study. We analyzed data from the Centers for Disease Control and Prevention (CDC) National Center for Health Statistics database and the Detailed Mortality Underlying Cause of Death database (CDC WONDER) from 2005 to 2014 that contains mortality and population counts for all U.S. counties. Bivariate correlations between the maternal mortality ratio and all maternal demographic, lifestyle, health, and medical service utilization characteristics were calculated. We performed a maximum likelihood factor analysis with varimax rotation retaining variables that were significant (P<.05) in the univariate analysis to deal with multicollinearity among the existing variables.RESULTS:
The United States has experienced an increase in maternal mortality ratio since 2005 with rates increasing from 15 per 100,00 live births in 2005 to 21–22 per 100,000 live births in 2013 and 2014. (P<.001) This increase in mortality was most pronounced in non-Hispanic black women, with ratios rising from 39 to 49 per 100,000 live births. A significant correlation between state mortality ranking and the percentage of non-Hispanic black women in the delivery population was demonstrated. Cesarean deliveries, unintended births, unmarried status, percentage of deliveries to non-Hispanic black women, and four or fewer prenatal visits were significantly (P<.05) associated with the increased maternal mortality ratio.CONCLUSION:
The current U.S. maternal mortality ratio is heavily influenced by a higher rate of death among non-Hispanic black or unmarried patients with unplanned pregnancies. Racial disparities in health care availability and access or utilization by underserved populations are important issues faced by states seeking to decrease maternal mortality.