Objective To investigate the relationship of periconceptional air pollution exposure in mothers with the birth weight of neonates.

Methods A three-year follow-up investigation was performed in the pregnant women who had regular antenatal examinations in a Three-A hospital of Nanning from January 2017 to January 2020. A face-to-face questionnaire survey was performed to collect related general information of the subjects, meanwhile, the data of the Air Quality Index (AQI) and the levels of PM_2.5, PM₁₀, SO₂, NO₂, and CO before pregnancy (12 weeks before pregnancy) and in early pregnancy (from the last menstruation to week 12 of pregnancy) were collected. A logistic regression model was used to analyze the influence of maternal periconceptional exposure to air pollution on the low birth weight of neonates.

Results All 1326 periconceptional mothers included in this study gave birth successfully, and there were 42 low-birth-weight infants, accounting for 3.17%. The AQI, PM_2.5, PM₁₀, SO₂, NO₂ and CO in winter were higher than those in other seasons in Nanning. Multivariate analysis results showed that elevated AQI during pre-pregnancy and early pregnancy, pregnancy hypertension, placenta previa and placental abruption were risk factors of low birth weigh neonates, with OR (95%CI) being 1.619(1.114~2.355), 1.531(1.087~2.158), 1.603(1.151~2.233), 1.519(1.121~2.058) and 1.478(1.045~2.092), respectively.

Conclusion Maternal exposure to air pollution during pre-pregnancy and early pregnancy is associated with the risk of low birth weight neonates.