Pregnancy Outcome in Occupational Tobacco Exposure: A Cohort Study from South India

BACKGROUND: Women constitute a significant labor pool in the Indian tobacco industry as bidi (hand-rolled cigarette) rollers. On an average, they roll around 600 bidis/day and are exposed to 120 g of tobacco and 3 g of nicotine. Bidis do not have chemical preservatives or stabilizing agents, and therefore, the rollers are exposed only to nicotine by handling and inhalation. The study objective was to assess pregnancy outcome in these women with occupational tobacco exposure. MATERIALS AND METHODS: A prospective cohort study of bidi-rollers (n = 177) and women with no tobacco exposure (n = 354), followed up for pregnancy outcome, neonatal anthropometry, and nicotine absorption by cotinine assays. Adjusted risk and adjusted mean differences with a 95% confidence interval were derived. RESULTS: Outcomes included increased adjusted risk for gestational hypertension (3.54 [1.21, 10.31]; P = 0.021) and fetal growth restriction (2.71 [1.39, 5.29]; P = 0.004). Risk for prematurity was not statistically significant (1.81 [0.74, 4.45]; P = 0.194). Lower adjusted mean difference of birth weight (−104 g [−177, −31]; P = 0.005), length (−0.4 cm [−0.8, −0.1]; P = 0.006), and head circumference (−0.4 cm [−0.6, −0.1]; P = 0.002) were seen with increased risk for small for gestational age (1.75 [1.12, 2.73]; P = 0.015). Nicotine absorption was evident in one-third of maternal and cord blood estimations. CONCLUSION: Occupational passive tobacco exposure results in adverse pregnancy outcome.