Trends in Pregnancy-Related Mortality in the United States

OBJECTIVE: To describe Pregnancy Mortality Surveillance System (PMSS)-identified underlying causes of pregnancy-related deaths and changes over time in the overall and cause-specific pregnancy-related mortality ratios in the United States, 2005-2024. METHODS: For this descriptive study, all pregnancy-related deaths were identified in the Centers for Disease Control and Prevention's PMSS from 2005 to 2024. The PMSS has nine 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 new cause-of-death code specific for coronavirus disease 2019 (COVID-19) was added to the infection or sepsis category. Cause-specific proportionate mortality was calculated overall and in 5-year intervals. In addition, trends in pregnancy-related mortality ratios, overall and by underlying cause of death, were assessed over time with Joinpoint regression. Joinpoint analysis identified statistically significant changes in trends (joinpoints) and in annual percent change (APC) across distinct time periods. RESULTS: During 2005-2024, 14,310 pregnancy-related deaths were identified in PMSS. There was a significant increase in the overall pregnancy-related mortality ratio from 2018 to 2021 (APC 20.11, P