Inpatient Maternal Mortality in the United States, 2002-2014

Although prior studies of inpatient maternal mortality in the United States provide data on the overall rate and trend in inpatient maternal mortality, there are no published reports of maternal mortality data stratified by timing of its occurrence across the pregnancy continuum (antepartum, intrapartum, and postpartum).

The study objective was to determine whether the maternal mortality rate, trends over time, self-reported race/ethnicity, and associated factors vary based on the timing of the occurrence of death during pregnancy.

We conducted a cross-sectional analysis of the Nationwide Inpatient Sample database to identify pregnancy-related inpatient stays stratified by timing. Among women in the sample, we determined in-hospital mortality and used International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify comorbidities and behavioral characteristics associated with mortality, including alcohol, drug, and tobacco use. Joinpoint regression was used to calculate rates and trends of in-hospital maternal mortality.

During the study period, there were 7,411 inpatient maternal mortalities among an estimated 58,742,179 hospitalizations of women 15-49 years of age. In-hospital maternal mortality rate stratified by race showed that African Americans died at significantly higher rates during antepartum, intrapartum, and postpartum periods compared to hospitalizations for Whites or Hispanics during the same time period. Although the postpartum hospitalization represents only 2% of pregnancy-related hospitalizations among women aged 15-49 years, hospitalization during this time period accounted for 27.2% of all maternal deaths during pregnancy-related hospitalization.

Most in-hospital maternal mortalities occur after hospital discharge from child birth (postpartum period). Yet, the postpartum period continues to be the time period with the least maternal healthcare surveillance in the pregnancy continuum. African American women experience three times more in-hospital mortality when compared to their White counterparts.