The Implementation of the Tennessee Fetal Assault Law and Its Association With Out-of-State Births Among Residents of Tennessee.

Introduction: This study analyzed the association between the implementation of the Tennessee Fetal Assault Law (TFAL), which allowed prosecutors to incarcerate people who used substances during pregnancy, and out-of-state births among residents of Tennessee.

Methods: The main data source is vital records on singleton births in hospitals to people aged 15-44 years during the period January 2010 to June 2016. We include data from 33 states and the District of Columbia where birth certificate data are comparable over this time period. The statistical significance of the difference in outcomes observed before and after TFAL implementation was tested using a difference-in-differences analysis between Tennessee and the comparison group.

Results: After TFAL implementation, the odds of having an out-of-state birth increased by 13% for residents of Tennessee (odds ratio, 1.13; 95% confidence interval, 1.09-1.16) relative to residents of the comparison states. When we adopted different thresholds for travel distances to the birth hospital, the odds of residents of Tennessee having an out-of-state birth more than 75 miles away increased by 17% (odds ratio, 1.17; 95% confidence interval, 1.13-1.21) after TFAL implementation.

Conclusion: The results of this study suggest that the implementation of a policy allowing incarceration of people who use substances during pregnancy is associated with an increase in out-of-state births, potentially putting pregnant people and their infants at greater risk.