LAUSR

ObjectivesActive smoking during pregnancy may increase the risk of gestational diabetes mellitus (GDM), but little is known about the potential association between passive smoking and risk of GDM. The present study investigated the association between passive smoking at home and/or in the workplace and risk of GDM among non-smoking Chinese women.MethodsA population-based study including 995 pregnant women taking antenatal care from December 2015 to May 2016 was conducted. Screening was carried out after 24 gestational weeks, during which women were offered a 75-g 2-h oral glucose tolerance test (OGTT). Basic information and self-reported passive smoking were collected by a questionnaire. Passive smoking was classified as passive smoking at home, passive smoking in the workplace, or passive smoking at home and in the workplace. They were further classified by time period, total exposure time, and amount. Logistic regression was used to estimate both crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs).ResultsThe prevalence of passive smoking was 78.3%. Compared with women who were non-exposed to passive smoking, a passive smoker has an increased risk of GDM with an adjusted OR (95% CI) of 1.60 (1.09, 2.33). In addition, there was a strong association between passive smoking exposure at home and GDM (adjusted OR 1.59; 95% CI 1.13, 2.24), and significant dose–response relationships in total exposure time and amount of passive smoking at home were observed. However, there is no obvious evidence for the link between passive smoking in the workplace and GDM risk (adjusted OR 1.25; 95% CI 0.87, 1.80).ConclusionsPassive smoking at home was associated with an increased risk of GDM among non-smoking Chinese women. These findings emphasize the importance of preventing passive smoking, especially at home.