Study finds many occur with no clinical risk factors

Stillbirths are a tragic reality for many families in the United States, with a new study revealing that the rate of stillbirths is higher than previously reported. Led by researchers at Harvard T.H. Chan School of Public Health and Mass General Brigham, the study sheds light on the need for improved stillbirth risk prediction and prevention efforts.

Published in JAMA, the study analyzed data from over 2.7 million pregnancies in the U.S. between 2016 and 2022, identifying 18,893 stillbirths. The researchers found that more than one in 150 births end in stillbirth, a rate higher than the national average previously reported by the Centers for Disease Control and Prevention.

One concerning finding of the study was that a significant portion of stillbirths occurred with no identified clinical risk factors, particularly those occurring at 40+ weeks gestation. This highlights the urgent need to enhance research and prevention efforts in this area to reduce the number of preventable stillbirths.

The study also uncovered disparities in stillbirth rates based on socioeconomic factors. Families living in low-income areas and areas with higher proportions of Black families experienced higher stillbirth rates. However, stillbirth rates did not significantly vary based on rurality or access to obstetric care.

Furthermore, the study revealed that later gestational ages had higher rates of stillbirths with no clinical risk factors. This underscores the importance of monitoring pregnancies closely, especially in the later stages, to prevent stillbirths.

Co-senior author Mark Clapp, a maternal-fetal medicine provider at Massachusetts General Hospital, emphasized the need for policy changes and further research to address the persistently high rates of stillbirths in the U.S. The study’s findings also point to the necessity of investigating the factors driving socioeconomic disparities in stillbirth rates.

Haley Sullivan, a student in the Harvard Ph.D. Program in Health Policy, led the study, with co-authorship from Harvard Chan’s Anna Sinaiko. The researchers hope that their work will inform future initiatives to prevent stillbirths and support families who have experienced this devastating outcome.

For more information, the study can be found in JAMA under the citation: Haley K. Sullivan, et al. Stillbirths in the United States. DOI: 10.1001/jama.2025.17392.

Provided by Harvard T.H. Chan School of Public Health, this research underscores the urgent need for improved stillbirth prevention strategies and increased support for families affected by stillbirths.