The effects of maternal exposure to second-hand smoke on breast-feeding duration: A prospective cohort study.

Aim: Encouraging exclusive breastfeeding up to 6 months is one of the main priorities for public health. However, the rate of exclusive breastfeeding is decreasing in Iran. Moreover, there have been few studies conducted on the effects of maternal exposure to cigarette smoke on breastfeeding duration in Iran. Considering the importance of breast milk for infant development, the future health of the baby and ultimately the family, this study was designed to assess the effect of maternal exposure to second-hand smoke on exclusive breastfeeding duration. Subjects and methods: The effect of smoke exposure on exclusive breastfeeding was investigated in a prospective cohort study. The study included 170 mothers in the exposed group and 170 mothers in the non-exposed group. There were losses to follow-up (12 %), so a statistical analysis was carried out on a total of 299 women. Breastfeeding duration and maternal exposure to second-hand smoke were recorded in three follow-up interviews, including 3-5 days, 3 months and 6 months after delivery. Maternal exposure to second-hand smoke was assessed by self-reports. A Kaplan-Meier survival analysis and Cox regression model were used for data analysis. Results: Maternal exposure to second-hand smoke during the postpartum period can cause a significant reduction in exclusive breastfeeding during a 6-month period ( p < 0.001). According to the Cox regression model, heavily exposed (hazard ratio = 2.22, 95 % confidence interval: 1.45-3.39) and lightly exposed mothers (hazard ratio = 1.65, 95 % confidence interval: 1.25-2.42) were more likely to stop exclusive breastfeeding earlier compared with non-exposed women. Conclusion: Maternal exposure to second-hand smoke is associated with an increased risk of discontinuation of exclusive breastfeeding before 6 months. A stance of no smoking at home and avoidance of passive smoking could possibly improve the rate of breastfeeding in Iran. [ABSTRACT FROM AUTHOR]