exposure to second-hand smoke during pregnancy and preterm delivery

background prematurity is an issue related to increasing the neonatal morbidity and mortality and smoking pregnant women cause the risk of low birth weight and prematurity increase, compared to non-smoking ones. results of all 205 women, 43 (20.97%) women exposed to shs during pregnancy and 162 (79.02%) women did not. in shs exposure group, 11 infant (25.6%) and in non- shs exposure group, 17 infant (10.5%), were born prematurely (< 37 weeks) (p = 0.01). also birth weight of newborn in non-shs exposure group was 118 gram more than other group but the differences were not significant (p = 0.09). materials and methods in this descriptive-analytic study, 205 women referred to both public and private hospitals in the third trimester were questioned about second-hand smoke (shs) exposure during pregnancy. in addition to birth weight and gestational age, other variables including mother’s education and job and sex of the newborns were also assessed. objectives this study investigates second-hand smoke (shs) exposure’s effects over pregnant women on gestational age and birth weight. conclusions our findings showed that the secondhand smoke (shs) exposure of pregnant women may be significantly associated with early preterm delivery.