Impact of tobacco control policies on disparities in low birthweight

Background: Maternal smoking during pregnancy is a major contributor of babies born low birthweight (LBW); however, changing maternal behaviors remains a significant challenge and little is known about whether tobacco control policies may indirectly affect infant outcomes.

Methods: We examined the impact of cigarette excise taxes and smoke-free legislation on disparities in LBW through differences-in-differences models utilizing repeated cross-sections of the Pregnancy Risk Assessment Monitoring System (PRAMS) from 2000-2007 for 21 states (N=235,969 mothers and their singleton infants). For each mother we calculated the average state-level cigarette tax during pregnancy (in dollars) from the Tax Burden on Tobacco and smoke-free legislation total score (0 [none]-32 [very strong] for the year of birth from the NCI's State Cancer Legislative Database. Infant birthweight was reported on the birth certificate; we calculated LBW as ≤2500 grams and all models were adjusted for gestational age, year, and other socio-demographic characteristics. From 2000-2007, 20 states increased taxes and 13 states strengthened smoke-free legislation.

Results: Although there was no overall impact of either tobacco control policy on LBW, significant interactions revealed that cigarette taxes may affect mothers differently by race/ethnicity, age, and education. There was evidence that tax increases reduced LBW babies for Black mothers (adjusted Coefficient -0.007; p=.008), mothers aged <17-19 years (-0.007; p=.02), and mothers with 0-11 years (-0.007; p=.001) and 12 years of education (-0.004; p=.04).

Conclusions: We found that state-level cigarette tax increases may also benefit infants and have the potential to reduce disparities in LBW.