20-year data show shifting causes of pregnancy-related death

A descriptive study published in Obstetrics & Gynecology examined 20 years of Pregnancy Mortality Surveillance System (PMSS) data to characterize the underlying causes of pregnancy-related deaths in the United States and how cause-specific mortality trends have shifted over time. The study drew on all pregnancy-related deaths identified in the Centers for Disease Control and Prevention's (CDC) PMSS from 2005 to 2024.

Researchers analyzed cause-specific proportionate mortality overall and in 5-year intervals across the PMSS's 9 mutually exclusive underlying cause-of-death categories: hemorrhage; infection or sepsis; amniotic fluid embolism; thrombotic pulmonary or other embolisms; hypertensive disorders of pregnancy; anesthesia complications; cerebrovascular accidents; cardiovascular conditions, including cardiomyopathy; and other noncardiovascular medical conditions. Beginning with 2020 data, a coronavirus disease 2019 (COVID-19)-specific cause-of-death code was added within the infection or sepsis category.

Trends in overall and cause-specific pregnancy-related mortality ratios were assessed using Joinpoint regression, which identified statistically significant changes in trends and annual percent change (APC) across distinct time periods.

Key data

• 14,310 pregnancy-related deaths were identified in PMSS during 2005-2024
• Overall pregnancy-related mortality ratio significantly increased from 2018 to 2021 (APC 20.11, P < .001), followed by a significant decrease from 2021 to 2024 (APC −17.91, P < .001)
• The most prevalent causes of death throughout the study period were infection or sepsis, cardiovascular conditions (including cardiomyopathy), other noncardiovascular medical conditions, and hemorrhage
• In 17 of the 20 years studied, cardiovascular conditions were the leading cause of pregnancy-related death
• Infection or sepsis deaths had the largest increase of any cause from 2018 to 2021 (APC 86.17, P < .001) and the largest decrease from 2021 to 2024 (APC −49.67, P < .001), coinciding with the timing of the COVID-19 pandemic
• Hemorrhage deaths showed an increasing pregnancy-related mortality ratio from 2017 to 2024 (APC 6.84, P = .02)
• The pregnancy-related mortality ratio for other cardiovascular conditions decreased from 2020 to 2024 (APC −9.49, P = .04)

Infection and sepsis trends closely tracked the pandemic timeline

The rise and subsequent decline in infection or sepsis deaths, the largest cause-specific swing observed in the study, lined up closely with the pandemic period, reflecting the addition of a COVID-19-specific code within that category beginning in 2020, according to the study authors.

Hemorrhage-related deaths continued climbing even as overall mortality declined

While the overall pregnancy-related mortality ratio decreased from 2021 to 2024, hemorrhage deaths followed a different trajectory, rising steadily from 2017 through 2024, a trend distinct from the pandemic-driven pattern seen in infection and sepsis deaths.

Cardiovascular conditions held the top position across most of the study period

Cardiovascular conditions, including cardiomyopathy, were the leading cause of pregnancy-related death in 17 of the 20 years examined, even as the specific ratio for other cardiovascular conditions declined between 2020 and 2024.

While cardiovascular conditions remained the most prevalent causes of pregnancy-related deaths, “cause-specific trends in pregnancy-related mortality in the United States have changed over time,” the authors wrote. “These differences underscore the importance of sustained surveillance to better inform clinical and public health efforts to address leading and emerging causes of pregnancy-related death.”

Reference:

Njie F, Hollier LM, Gibson C, et al. Trends in pregnancy-related mortality in the united states: pregnancy mortality surveillance system, 2005–2024. Obstetrics & Gynecology. Published online August 7, 2026. doi:10.1097/AOG.0000000000006396