Effect of stop smoking during the first trimester on Low birth weight: A MCBR Study

Abstract

Abstract Background Tobacco smoking is a public health problem. Even though this habit is less common among women than men in Russia, it appears to be on the increase among women aged ≥15 years. Smoking during pregnancy leads to adverse pregnancy and birth outcomes. Compared to the number of studies on maternal smoking and birth weight, the influence of stop smoking on low birth weight is not well documented. The aim of the study was to assess an effect of quitting smoking during the first trimester on low birth weight. Methods The study is based on the Murmansk County Birth registry. Women who delivered a singleton pregnancy after 37 weeks of gestation were comprised to the study (N = 44,486). Smoking information was assessed at the first antenatal visit during pregnancy and self-reported and. Low birth weight was defined in according to the World Health Organization as Mean value minus 2 standard deviations for girls and boys separately. Using logistic regressions, we adjusted for maternal age, residence, ethnicity, education, marital status, alcohol abuse, year of delivery, body mass index, pregnancy diabetes, gestational age, and excessive weight gain. Results The prevalence of low birth weight was 1.1%. This adverse birth outcome was more prevalent in women who smoked during pregnancy (2.5%) in compared to those who stopped do it during pregnancy (0.8%) or did not smoke before and during pregnancy (0.9%) (p < 0.001). Compared to non-smokers, quitting smoking during the first trimester had no significant impact on the low birth weight, even after adjustment for confounders (ORcrude = 0.97 with 95%CI 0.64-1.47 and ORadj = 0.89 with 95%CI 0.58-1.36). Conclusions We observed that women who stop smoking during the first trimester are at no greater risk of having a term baby with low birth weight. Our findings underline a continued need for actions against smoking during pregnancy. Key messages Women who stop smoking during the first trimester are at no greater risk of having a term baby with low birth weight. Our findings underline a continued need for actions against smoking during pregnancy.