Trends in Postpartum Hemorrhage Prevalence and Comorbidity Burden: Insights from the ENACT Network Aggregated Electronic Health Record Data.

The goal of this study was to assess trends in postpartum hemorrhage (PPH), its risk factors, and maternal comorbidity burden in the United States using aggregate data from the Evolve to Next-Gen Accrual to Clinical Trials (ENACT) network. This federated network employs interactive querying of electronic health record data repositories in academic medical centers nationwide. We conducted repeated annual cross-sectional analyses to evaluate PPH occurrence and comorbidities across various ethnoracial and sociodemographic groups, starting with a large cohort of 1,287,675 unique delivery hospitalizations collected from 22 ENACT sites between 2005 and 2022. During this time, there was a statistically significant increasing trend in the prevalence of PPH, rising from 5,634 to 10,504 PPH per 100,000 deliveries (P <0.001). Our findings revealed a continuous upward trend in PPH rates that remained consistent among women with ≥ 1 comorbid conditions (P <0.001) and those with ≥ 1 maternal risk factor (P <0.001). This result aligns with prior studies and extends beyond the time periods previously reported. Overall, Native Hawaiian or Other Pacific Islander women had the highest PPH prevalence (~ 13%), followed by Asian (9.8%), American Indian or Alaska Native (8.9%), multirace (8.6%), Black or African American (8.4%) and White (7.4%) women. The top PPH risk factor identified was placenta previa or accreta, while the top comorbidity was antepartum hemorrhage / placental abruption. The most common cause of PPH, namely uterine atony, was prevalent in ENACT data. Our analysis highlights significant ethnoracial disparities and underscores the need for targeted preventative interventions.