Pregnancy-Related Deaths in the US

A recent report found that 3 of every 5 pregnancy-related deaths in the US are preventable and that heart disease and stroke are the leading cause of pregnancy-related death.

Investigators found that 700 women die annually from pregnancy-related deaths and black women are 3 times more likely to experience a pregnancy-related death compared to their white counterparts.

“This paper is a reminder that we must address prevention opportunities every step of the way — ensuring women receive high quality and timely care during pregnancy, at delivery and up to a year afterward,” said Emily Peterson, MD, medical officer in the Center for Disease Control and Prevention's Division of Reproductive Health.

Investigators from the CDC Prevention examined the timing and characteristics pregnancy-related deaths within 1 year of delivery from 2011 to 2015 from the Pregnancy Mortality Surveillance System (PMSS). Additionally, they used data from 13 states’ maternal mortality review committees (MMRC) from 2013 to 2017 to determine the amount of deaths that were preventable and what factors contributed to the deaths.

Investigators defined a pregnancy-related death as death was caused by a pregnancy complication, a chain of events initiated by pregnancy, or the aggravation of an unrelated condition by the physiologic effects of pregnancy.

Between 2011 and 2015, investigators identified a total of 3410 pregnancy-related deaths within the US, which is 17.2 per every 100,000. Black women had the higher mortality rate at 42.8 per 100,000, followed by American Indian/Alaska Native at 32.5 per 100,000. Authors noted that these rates were 3.3 and 2.5 times higher, respectively, than the rate of white women, which was 13.0 per 100,000. Mortality rates were also higher among women 35 or older and women who were not married.

When analyzing the causes of pregnancy-related deaths, investigators found that, when combined, cardiovascular conditions were responsible for more than 33% of all deaths that occurred. Specifically, cardiomyopathy caused 10.8%, cerebrovascular accidents caused 7.8%, and other cardiovascular conditions caused 15.1%. Other frequent causes included other non-cardiovascular medical conditions (14.3%), infection (12.5%), and obstetric hemorrhage (11.2%). Investigators noted that cause of death could not be determined in 6.7% of cases.

Investigators were able to obtain the timing of death for 87.7% (2990) of the pregnancy-related deaths examined. With 31.1% (937) pregnancy-related deaths, during pregnancy was the most common time for a death to occur. There were 506 (16.9%) day of delivery deaths, 556 (18.6%) that occurred 1 to 6 days postpartum, 640 (21.4%) between 7—42 days postpartum, and 351 (11.7%) between 43 and 365 days postpartum.

Authors noted that there was a correlation between the cause of pregnancy-related deaths and timing of death relative to the end of the pregnancy. From 6 weeks postpartum to the end of the first year, cardiomyopathy was the leading cause of death. On the day of delivery, hemorrhage and amniotic fluid embolism were the major causes of death. Hemorrhage, hypertensive disorders of pregnancy, and infection were leading causes of death during the first 6 days postpartum.

From the MMCRs, investigators identified a total of 251 deaths examined for preventability and found that a determination was made for 92.4% (232). They determined that 60% of the 232 deaths were preventable. Unlike the information drawn from the PMSS, investigators found preventability rates to be similar across all races/ethnicities and timing of death.

This analysis, titled “Pregnancy-Related Deaths, United States, 2011—2015, and Strategies for Prevention, 13 States, 2013–2017,” was published online on the CDC’s website.