The effect of maternal exposure to air pollutants on small for gestational age among infants in Xuzhou, China from 2018 to 2020: a cross sectional study

Background: Small for gestational age (SGA) defined as below 10th percent of birth weight of sex-specific gestational age, will bring large burden to the child. Large epidemiological studies have shown that exposure to air pollutants during pregnancy is associated with SGA, but the conclusions are inconsistent. Objective: To further investigate the relationship between prenatal exposure to air pollutants and SGA in Xuzhou, China. Methods: : Our study included 2,039 pairs of mothers and their fetuses from January 1, 2018 to December 31, 2020 at the Affiliated Hospital of Xuzhou Medical University. A total of six air pollutants were acquired from the Xuzhou Department of Environmental Protection including particulate matter, nitrogen dioxide (NO 2 ), and sulfur dioxide (SO 2 ), ozone (O 3 ), carbon monoxide (CO). Adjusted for the confounders referring gestation, parity, gestational diabetes mellitus and Meteorological factors. We performed binomial logistic regression to test the odds ratio between air pollutants and the risk of SGA. Results: : We found strong positive association of exposure to SO 2 with SGA over the entire pregnancy and during the 1th, 2nd trimester (OR, 95% confidence interval: 1.204(1.091-1.328), 1.165(1.073-1.266), 1.110(1.033-1.193)). The other pollutants exception of O 3 and NO 2 were also found moderate relation with SGA over the entire pregnancy. Conclusions: : The SGA incidence in Xuzhou was still high and even exposure to low levels of SO 2 will pose a significant risk to infants. The government should focus on relevant policies to further improve air quality to reduce the burden of medical and health work and promote maternal health.