Vol.:(0123456789) 1 3 Maternal and Child Health Journal https://doi.org/10.1007/s10995-019-02751-2 Smoking Cessation and Pregnancy: Timing of Cessation Reduces or Eliminates the Efect on Low Birth Weight Pamela K. Xaverius 1  · Zach O’Reilly 2  · April Li 1  · Louise H. Flick 1  · Lauren D. Arnold 1 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Background Women who smoke cigarettes while pregnant are at elevated risk of having low birth weight infants (LBW, < 2500 g) which increases risks of infant mortality and morbidity, including chronic conditions later in life. Objective Smoking cessation during pregnancy can reduce the risk of poor birth outcomes. However, the efect that timing of smoking cessation has on the reduction of poor birth outcomes in term pregnancies is unknown. Study Design This retrospective cohort study used birth certifcate data from Missouri singleton, full-term, live births from 2010 to 2012 (N = 179,653) to examine the rates and timing of smoking cessation during pregnancy on birthweight. Smok- ing exposure was categorized as non-smoker, preconception cessation, frst trimester cessation, second trimester cessation, and smoker. The outcome was low birth weight (LBW). Covariates included maternal race/ethnicity, age, education level, type of payment for the delivery, marital status, paternal acknowledgement, prenatal sexually transmitted infection (STI), comorbidities, and body mass index. Bivariate and multivariable analyses were used to assess relationships between smok- ing and LBW status. Results Preconception cessation did not have a statistically higher risk for LBW than mothers who never smoked (aOR 1.12; 95% CI 0.98, 1.28). First trimester cessation (aOR 1.26; 95% CI 1.05, 1.52), second trimester cessation (aOR 2.00; 95% CI 1.60, 2.67), and smoker (aOR 2.46; 95% CI 2.28, 2.67) had increasing odds for LBW relative to mothers who did not smoke. All covariates had signifcant relationships with the smoking exposure. Conclusion Preconception cessation yielded LBW rates comparable to non-smokers. The risk for LBW increased as smoking continued throughout pregnancy among full term births, an important new fnding in contrast with other studies. Keywords Smoking · Pregnancy · Low birth weight Signifcance Women who smoke cigarettes while pregnant are at elevated risk of having low birth weight infants (LBW, < 2500 g) which increases risks of infant mortality and morbidity, including chronic conditions later in life. Smoking cessation during pregnancy can reduce the risk of poor birth out- comes. However, the efect that timing of cessation has on the reduction of smoking’s efects on birth outcomes in term pregnancies is unknown. To our knowledge, by employing the methodology in our study that required the limiting of our sample to full term births, we were able to add to the lit- erature that there are progressive increases to risks for LBW as smoking continues throughout the pregnancy. Introduction Approximately 23% of women in Missouri smoke cigarettes (i.e., smoking) compared to 17.4% in the entire US, a rate that drops to only 17% among pregnant women (Center for Tobacco Policy Research [CTPR] 2007; Missouri Informa- tion for Community Assessment [MICA] 2014). Smoking is * Pamela K. Xaverius pxaveriu@slu.edu Louise H. Flick ficklh@slu.edu Lauren D. Arnold larnold7@slu.edu 1 College for Public Health and Social Justice, Saint Louis University, 3545 Lafayette Avenue, St. Louis, MO 63104, USA 2 St. Louis, USA