Pregnancy-related deaths and strategies for prevention

May 14, 2019

A new report analyzed the timing and cause of maternal deaths to determine preventability, factors that contributed to pregnancy-related deaths, and also identified prevention strategies to address contributing factors.

One of the issues that repeatedly came up throughout Contemporary OB/GYN’s 2018 coverage of the maternal mortality crisis was the issue of racial disparity. A recently released report from the Centers for Disease Control and Prevention(CDC) Morbidity and Mortality Weekly Report examined the timing and characteristics of pregnancy-related deaths in the United States between 2011 and 2017 and how these deaths were dispersed among racial groups.

The authors used data from the CDC’s national Pregnancy Mortality Surveillance System (PMSS) from 2011-2015 as well as data from 13 state maternal mortality review committees (MMRC) from 2013-2017. Sociodemographic data were used to calculate pregnancy-related mortality ratios (PRMRs). Timing and cause of deaths were analyzed to determine preventability, factors that contributed to pregnancy-related deaths, and MMRC-identified prevention strategies to address contributing factors. 

Between 2011 and 2015, 3,140 pregnancy-related deaths occurred in the United States. The national PRMR for that period was 17.2 per 100,000 live births. However, non-Hispanic black and American Indian/Alaska Native women had PRMRs that were more than 3.3 and 2.5 times higher than the national PRMR (42.8 and 32.5, respectively). The PRMR for non-Hispanic white women was 13.0. 

Time of death was known for 2,990 (87.7%) pregnancy-related deaths. Approximately one-third (937, 31.3%) of these deaths occurred during pregnancy, 506 (16.9%) occurred on the day of delivery, 556 (18.6%) 1 to 6 days postpartum, 640 (21.4%) 7 to 42 days postpartum, and 351 (11.7%) 43 to 365 days postpartum. Although timing of deaths did not significantly differ between white and black women, a greater proportion of deaths among black women (14.9%) occurred 43 to 365 days postpartum compared to white women (10.2%).

The authors noted that the leading cause of death varied by timing. Deaths on the day of delivery were most often caused by amniotic fluid embolism. More than half (60%) of deaths caused by hypertensive disorders of pregnancy occurred 0 to 6 days postpartum. Cerebrovascular accidents occurred most frequently between 1 and 42 days postpartum. Deaths caused by cardiomyopathy occurred most often 43 to 365 days postpartum.

Among the 251 pregnancy-related deaths evaluated for preventability by the 13 MMRCs, a determination was made for 232 (92.4%). Sixty-percent (139) of these deaths were determined to be preventable. Preventability did not significantly differ between races or by timing of death. 

MMRC data identified an average of three to four contributing factors and two to three prevention strategies per pregnancy-related death. Contributing factors fell into the following categories: community factors, health facility factors, patient factors, provider factors, and system-level factors. The MMRCs suggested that expanding clinical office hours and the number of providers who accept Medicaid, prioritizing pregnant and postpartum women for temporary housing programs and improving access to transportation could help address some of the community factors. Implementing obstetric emergency protocols and simulation training and providing telemedicine could help address health facility factors. Improving provider education could help reduce missed or delayed diagnoses and implementing a maternal early warning system could help reduce provider-level contributing factors.