The association between adverse birth outcomes and smoking cessation during pregnancy across the United States—43 States and New York City, 2012–2017

Purpose This cross-sectional study aimed to estimate the risks of adverse birth outcomes among pregnant smokers and the benefits of smoking cessation during pregnancy on birth outcomes across the United States. Methods We performed an analysis of 203,437 pregnant women using data collected by the Pregnancy Risk Assessment Monitoring System (PRAMS) from 2012 to 2017. PRAMS uses questionnaires and birth certificates to collect information about the socio-demographic characteristics of pregnant women, smoking status before and during pregnancy, and birth outcomes. We assessed the relationship between self-reported smoking status during pregnancy and preterm birth, low birth weight, and small-for-gestational-age using multivariable logistic regression models. Results In our study population, 80.43% of pregnant women never smoked, 10.55% of pregnant women quit smoking during pregnancy, and 9.02% continued smoking during pregnancy. Puerto Rico had the highest prevalence of non-smokers (94.12%), while West Virginia had the lowest prevalence of non-smokers (60.54%). Pregnant women who had a higher education level, were married, had less than 5 types of stress, and had government or private insurance before pregnancy had a higher prevalence of smokers who quit during pregnancy (quit smokers) than those that continued smoking (continuous smokers). Compared to non-smokers, continuous smokers had a significantly higher risk of low birth weight (AOR: 1.91, 95% CI 1.80, 2.03), preterm birth (AOR: 1.31, 95% CI 1.21, 1.41), and small-for-gestational-age (AOR: 2.22, 95% CI 2.07, 2.39). However, the relationships between quitting smoking and preterm birth and small-for-gestational-age were not significant. Conclusion Our models suggest that smoking cessation during pregnancy can prevent adverse birth outcomes by significantly reducing the risk of preterm birth and small-for-gestational-age to almost comparable to not smoking.