Prof. Alison Gemmill discusses her recent study “US Abortion Bans and Infant Mortality” with CCPR

Alison Gemmill, Associate Professor of Epidemiology, has joined CCPR as a faculty affiliate, bringing expertise in fertility, maternal and perinatal health, and the structural and political determinants of health in the US. Her recent work examines the consequences of the Supreme Court’s Dobbs v. Jackson Women’s Health Organization decision to overturn decades of constitutional protection for abortion rights. For this work,  Professor Gemmill and collaborators are recipients of the 2025 Outstanding Statistical Application Award from the American Statistical Association, which is awarded for the innovative use of statistical methods to address significant problems in a substantive field (American Statistical Association, n.d.). The award specifically acknowledges two companion studies published in JAMA in February 2025, which provide some of the most comprehensive early evidence on the population-level effects of abortion bans.

The first study, “US Abortion Bans and Fertility,” assessed fertility changes following abortion bans in 14 states (Bell et al., 2025). The study found approximately 22,000 excess births beyond expected levels from 2021 to 2023, with the largest increases among racially minoritized individuals, Medicaid beneficiaries, younger women, and those without college degrees.

Professor Gemmill discusses the second study, “US Abortion Bans and Infant Mortality,” in more detail with CCPR. Using national birth and death certificate data, Gemmill and collaborators found an estimated 5.6% increase in infant mortality in states that enacted abortion bans, equivalent to about 478 additional infant deaths in the first year after the bans took effect (Figure 2; Gemmill et al., 2025). The increases were most pronounced among Black infants and in deaths associated with congenital anomalies, both with a relative increase of 11% more than expected. In contrast, infant deaths not due to congenital anomalies also rose, but at a rate of about 4% more than expected.

Figure 2. Estimated Difference in Cumulative Observed vs Expected Infant Deaths in All US States With Abortion Bans in Months Affected by Bans

Professor Gemmill elaborated on the mechanisms underlying these findings: “What we found was that the abortion bans in states are related to this increase in infant mortality. But a large portion of that increase is due to babies being born with fatal congenital anomalies.” She noted that legislative exceptions for severe anomalies may not be sufficient to prevent such outcomes. “Even if legislation makes exceptions for fetal anomalies, you still might see this increase in infant mortality… pregnancy complications are complex and hard to define on paper in a policy.”

She emphasized the importance of translating findings for audiences beyond academia. “We’re actually working with a senator’s office to help do more of this work,” she noted, describing efforts to make the research accessible and relevant for policymakers at both state and federal levels. She and her colleagues recently organized a symposium in Washington, D.C., focused on the role of evidence in informing abortion policy.

Her ongoing projects continue to address maternal and reproductive health outcomes. “The next step is around maternal health. We have a paper under review on maternal mortality, and then we’re looking at maternal morbidity, which includes very severe complications,” she explained. 

In addition to her work on abortion policy, Professor Gemmill has been engaged for more than a decade in research on U.S. fertility decline. She is co-PI of a NSF grant to develop a U.S. Human Fertility Database at the state and county level. “That’s a big part of my work going forward,” she said, describing plans to use the resource to investigate how economic and social conditions shape fertility patterns and intentions.

Her work demonstrates how rigorous demographic and epidemiological research can illuminate the health consequences of legislative change, while also contributing critical data infrastructure for the study of fertility and reproduction in the United States. As a new CCPR faculty affiliate, she brings a portfolio of scholarship that not only addresses urgent questions about maternal and infant health but also informs broader policy conversations about reproductive health across the life course.

 

 

References

American Statistical Association. (2025). Outstanding Statistical Application Award. Retrieved September 25, 2025, from https://www.amstat.org/your-career/awards/outstanding-statistical-application-award

Bell, S. O., Franks, A. M., Arbour, D., Anjur-Dietrich, S., Stuart, E. A., Ben-Michael, E., Feller, A., & Gemmill, A. (2025). US abortion bans and fertility. JAMA, 333(15), 1324–1332. https://doi.org/10.1001/jama.2024.28527

Gemmill, A., Franks, A. M., Anjur-Dietrich, S., Ozinsky, A., Arbour, D., Stuart, E. A., Ben-Michael, E., Feller, A., & Bell, S. O. (2025). US abortion bans and infant mortality. JAMA, 333(15), 1315–1323. https://doi.org/10.1001/jama.2024.28517