The Relationship Between Maternal Passive Smoking During Pregnancy and Preterm Delivery

Background: Maternal passive smoking or exposure to environmental tobacco smoke may be a risk factor for maternal and newborn morbidity. Objectives: The current study aimed to assess the relationship between preterm delivery and tobacco smoke exposure in pregnant woman referring to the Shabih-Khani maternity hospital in Kashan, Iran. Patients and Methods: An analytical retrospective cohort study was conducted on 300 non-smoker pregnant women in two groups of passive smoking and non- passive smoking. Passive smoking was defined as exposed to smoking of 5 or more cigarettes per day during pregnancy at home. Preterm delivery compared between passive smoking and non-passive smoking groups. Results: Preterm delivery in the passive smoking group was more than non-passive smoking group (10% versus 6%, P = 0.2), this difference was not significant. Gestational age was similar in the two groups (38.96 ± 1.56 and 38.99 ± 1.42 weeks in the passive and non-passive smoking groups respectively). Conclusions: Preterm delivery in the exposed group was more than non-exposed group, but difference was not significant.