Prevalence of maternal passive smoking and its impact on pregnancy following implementation of an anti-smoking legislation in Shanghai, China: a cross-sectional study

Background: To investigate the prevalence of maternal passive smoking during pregnancy in Shanghai following the implementation of an indoor places anti-smoking legislation, and to assess the impact of maternal passive smoking on the occurrence of pregnancy complications and neonatal outcomes. Methods: We conducted a cross-sectional study among pregnant women at the Shanghai First Maternity and Infant Hospital, China. A self-administered questionnaire, distributed to women within 24 hours of delivery, was used to obtain demographic information and identify potential confounders. Information on pregnancy complications and neonatal outcomes was extracted from medical records. Logistic regression and linear regression models were used to estimate the risk of pregnancy complications and neonatal outcomes. Results: A total of 1063 women were included in this study. The prevalence of maternal passive smoking was 34.81%. Majority of passive smokers (77.38%) lived with family members consumed less than 5 cigarettes per day totally. We were unable to show any statistically significant correlation between passive smoking and pregnancy complications or neonatal outcomes. Conclusions: In Shanghai, the prevalence of maternal passive smoking decreased following the implementation of an indoor places anti-smoking legislation. Based on the present prevalence, no significant effects on pregnancy complications or neonatal outcomes were observed in short term.