RESUMO
To estimate the prevalence of waterpipe smoking among rural pregnant women in Southern Iran and to identify the impact of maternal waterpipe smoking on baby's birth weight. Subjects and Methods: A population-based survey was conducted in rural areas of Southern Iran in 2004 using existing health records and interviewing all mothers during the 10 days after delivery. Maternal exclusion criteria included cigarette smoking during pregnancy, a history or occurrence of epilepsy, diabetes and hypertension [gestational and/or essential] during pregnancy, factors that have been proved to have detrimental effects on birth weight. Of the 2,808 mothers interviewed, 224 [8%] were waterpipe smokers of which 90 [3.2%] and 134 [4.8%] were occasional [smoking less than once per day] and daily [at least once per day] smokers, respectively. Six hundred and seventy-four [24%] were passively exposed to waterpipe smoke during pregnancy and 322 [11.5%] were exposed to second-hand cigarette smoke. Mothers who started smoking during the first trimester had lower birth weight babies [3,215 +/- 612 g] compared to those who started smoking during the second or third trimesters [3,447 +/- 550 g, p = 0.04]. Waterpipe smoking during pregnancy is prevalent in Southern Iran and appears to be a risk factor for low birth weight babies