Voting Restrictions and Increased Odds of Adverse Birth Outcomes in the US.

Background: Disparities persist in adverse birth outcomes - preterm birth and small-for-gestational age (SGA) among racialized populations. Previous studies have indicated that voting restrictions are associated with health outcomes, such as access to health insurance and teenage birth rates. This paper examines whether the association between voting restrictions and adverse birth outcomes varies according to birthing individuals' race/ethnicity.

Methods: These analyses merged individual-level 2019-2020 Pregnancy Risk Assessment Monitoring System (PRAMS, 8th edition) data with state-level exposure information. The exposure, the Cost of Voting Index (COVI), is a 2020 state-level measure of voting restrictions, and the outcomes were preterm birth and SGA. Multilevel logistic regression, survey-weighted models adjusted for sociodemographic and geographically-based characteristics. Subanalyses examined if the association differed by race (non-Hispanic White, non-Hispanic Black, Hispanic, API, Other).

Results: In the unadjusted model, a standard deviation increase in COVI was associated with increased odds of preterm birth (OR = 1.11, 95% CI = 0.98, 1.25) and SGA (OR = 1.12, 95% CI = 1.02, 1.22). The association for SGA was still significant in the fully adjusted models. Results differed by race/ethnicity with the largest effects among API (OR = 1.20, 95% CI = 0.95, 1.52) for preterm birth and OR = 1.27, 95% CI = 1.01, 1.59) for SGA respectively).

Conclusion: Our results suggest structural voting barriers disproportionately increase the odds of adverse birth outcomes, especially for API-birthing individuals. Increasing voting restrictions may amplify existing birth inequities.