Examining the Effects of Timing of Earned Income Tax Credit on Preterm Births in California: Can a Natural Experiment Inform the Best Points of Intervention?

Deborah Karasek , University of California, San Francisco
Akansha Batra, University of California, San Francisco
Rebecca Baer, University of California, San Diego
Laura Jelliffe-Pawlowski, University of California, San Francisco
Rita Hamad, University of California, San Francisco

Background. Nearly 10 percent of births in the US are considered preterm, and are the leading cause of infant mortality and morbidity. We examine if there is variation in preterm birth as a result of the trimester of pregnancy in which EITC was received. Methods. The study population was births from the California Birth Cohort, 2005-2011 (N=3,749,946). We use difference-in-difference models to assess the effect of trimester of EITC exposure on preterm birth, control for potential confounding variables. Results. First trimester (=0.004, 95% CI(.002-.006)) second trimester (=0.004, 95% CI (.002, 006)) and third trimester (=0.005, 95% CI(.003, .007)) exposure compared to the preconception period were associated with elevated risk of preterm birth in adjusted models. Conclusion. We found that receipt of income in the months prior to conception appears to have a protective effect for preterm birth. These findings indicate that social policy may alter risk environment for pregnancy and childbirth.

See extended abstract

 Presented in Session 5. Health & Mortality 1