Effects of maternal exposure to indoor air pollution on maternal health and pregnancy outcomes in Wenzhou City, China

Indoor air pollution, originating from household and chemical sources, has attracted increasing attention as an important risk factor for maternal and fetal health in densely populated Chinese cities such as Wenzhou, due to the widespread use of chemical products and inadequate ventilation. This study investigated its impact on maternal health and pregnancy outcomes, in which 520 nonsmoking pregnant women (aged 18-40 years) from antenatal clinics in Wenzhou were enrolled in a prospective cohort study. Indoor pollutants (concentrations of formaldehyde, nitrogen dioxide, volatile organic compounds) were measured at 34 weeks of pregnancy using passive sampling methods, and maternal health data (gestational diabetes mellitus, gestational hypertension, respiratory symptoms) and pregnancy outcomes (gestational age, birth weight, body length, head circumference) were collected from medical records and questionnaires and analyzed with multivariate logistic and linear regression. The results showed that exposure to concentrations of formaldehyde, nitrogen dioxide, benzene, toluene, ethylbenzene, xylenes, environmental tobacco smoke, and proximity to the road were associated with increased risk of gestational diabetes mellitus (OR=1.18-1.47), gestational hypertension (OR=1.20-1.52), respiratory symptoms (OR=1.19-1.61), and decreased gestational age, birth weight, body length, and head circumference (β=-0.08 to -0.33). Consequently, indoor air pollution significantly threatens maternal health and fetal development, highlighting the need for targeted interventions such as improving ventilation and reducing chemical use to protect pregnant women and infants in urban environments.