ObjectiveTo explore the impact of air pollution on low birth weight in Minhang District, Shanghai, China.

MethodsAll cases of newborns were obtained from the department of gynaecology and obstetrics in six hospitals of Minhang District during the period of 2015 to 2016.Air quality measurements during the period were collected from a nearby state-controlled station.A multivariate logistic regression model with the presence of a low birth weight as the dependent variable and a multivariate linear regression model with the birth weight as the dependent variable were established to investigate the associations between air pollution exposure in the first, second, and third trimester and the incidence of low-birth-weight newborns and the birth weight after controlling for individual-level and ambient-level confounder.

ResultsDuring the study period, the average birth weight in Minhang District was 3 359 g, of which 3.01% was less than 2 500 g (i.e., low birth weight).In the first trimester, all air pollutants did not have significant impacts on the incidence of low birth weight and the birth weight.In the second trimester, exposure to fine particles and carbon monoxide could significantly increase the incidence of low birth weight.Fine particles, sulfur dioxide and carbon monoxide could significantly decrease the birth weight.In the third trimester, all pollutants other than sulfur dioxide could significantly increase the incidence of low birth weight, of which ozone had the strongest impact; ozone alone had significantly adverse association with birth weight.

ConclusionAir pollution in Minhang District could reduce the birth weight and increase the incidence risk of low birth weight.However, these impacts vary by different air pollutants and different trimesters of exposure.