FOR IMMEDIATE RELEASE
April 24, 2026
Contact: HHS Office on Women’s Health Press Office
Email: ashmedia@hhs.gov
WASHINGTON — A new national study conducted by the U.S. Department of Health and Human Services (HHS) Office on Women’s Health (OWH) published in The Lancet Regional Health – Americas, introduces a more accurate way to identify pregnant patients at risk for serious complications during childbirth.
The study analyzed 7,174,412 inpatient hospital deliveries that took place between 2016 to 2023 across 864 hospitals in 49 states. Researchers developed and tested a framework, the maternal Prenatal Risk Index (m-PRI), to improve how clinicians identify patients at risk for severe maternal morbidity (SMM), which includes life-threatening complications during delivery.
Unlike existing methods that treat all complications the same, the m-PRI accounts for how severe different conditions are and how strongly they are linked to maternal death. Using a mortality-informed approach to SMM severity provides a more detailed and accurate picture of patient risk.
“This new index gives clinicians a clearer, more precise way to identify pregnant women who may be at risk for serious complications before they occur,” said Assistant Secretary for Health Admiral Brian Christine. “By improving how we assess risk, we can better support timely care, strengthen clinical decision-making, and ultimately improve outcomes for mothers across the country.”
About the m-PRI
To build the index, researchers evaluated 46 potential risk factors and ultimately included 28 key conditions. Among the patients studied, about 1% (56,612 patients) experienced at least one SMM event, with cases ranging across four mortality-informed severity levels. SMM incidence and severity varied substantially by condition, with placenta accreta spectrum, chronic renal disease, and acquired cardiac disease showing the strongest associations with greater SMM severity.
Compared with the Obstetric Comorbidity Scoring System (OCSS), the m-PRI performed better at identifying patients at risk and performed consistently across age groups, demographics, and insurance types. Notably, 97% of patients with SMM had a detectable risk score, suggesting the m-PRI may support earlier identification of higher-risk patients.
Overall, the m-PRI offers a more precise, patient-centered way to assess risk by capturing both the presence and severity of maternal health conditions. This approach can support earlier intervention, improve care planning, and inform efforts to enhance maternal health outcomes nationwide.
Potential Uses of the m-PRI
Identifying patients at higher risk for SMM during pregnancy
Analyzing retrospective outcomes to identify hidden gaps in maternal health care
About the HHS Office on Women’s Health
The HHS Office on Women’s Health (OWH) works to improve the health of women and girls by developing programs, educating health care professionals, and motivating behavior change in consumers through the dissemination of health information. For more information, visit www.womenshealth.gov.