The downstream effects of state tobacco control policies on maternal smoking during pregnancy and birth outcomes.

Abstract

Research has demonstrated that the implementation of tobacco control policies is associated with improved birth outcomes. Ascertainment of prenatal smoking on the US birth certificate has changed over the past decade to record smoking across each trimester. Using 2005-2015 birth certificate data on 26,436,541 singletons from 47 states and DC linked to state-level cigarette taxes and smoke-free legislation, we conducted conditional mixed-process models to examine the impact of tobacco control policies on prenatal smoking and quitting, then on the associated changes in birth outcomes. We included interactions between race/ethnicity, education, and taxes and present average marginal effects. Among white and black mothers with less than a high school degree, 36.0% and 14.1%, respectively, smoked during the first trimester and their babies had the poorest birth outcomes. However, they were the most responsive to cigarette taxes. Every $1.00 increase in taxes was associated with a 3.45 percentage point decrease in prenatal smoking among white mothers and a 1.20 percentage point decrease among black mothers. These reductions translated to increases in birth weight by 4.19 g for babies born to white mothers and 0.89 g for babies born to black mothers. Among smokers, there was some evidence that taxes increased quitting and improved birth outcomes, although most associations were not statistically significant. We found limited effects of smoke-free legislation on smoking, quitting or birth outcomes. Cigarette taxes continue to have important downstream effects on reducing prenatal smoking and improving birth outcomes among the most vulnerable mothers and infants.