Association of Fine Particulate Matter and Its Components with Macrosomia: A Nationwide Birth Cohort Study of 336 Chinese Cities

Prenatal exposure to PM2.5, especially to itsfuel combustion-related components, was associated with increasedmacrosomia risk. Toexamine the associations between macrosomia risk and exposureto fine particulate matter (PM2.5) and its chemical componentsduring pregnancy, we collected birth records between 2010 and 2015in mainland China from the National Free Preconception Health ExaminationProject and used satellite-based models to estimate concentrationsof PM2.5 mass and five main components, namely, black carbon(BC), organic carbon (OC), nitrate (NO3 (-)), sulfate (SO4 (2-)), and ammonium (NH4 (+)). Associations between macrosomia risk and prenatalexposure to PM2.5 were examined by logistic regressionanalysis, and the sensitive subgroups were explored by stratifiedanalyses. Of the 3,248,263 singleton newborns from 336 cities, 165,119(5.1%) had macrosomia. Each interquartile range increase in concentrationof PM2.5 during the entire pregnancy was associated withincreased risk of macrosomia (odds ratio (OR) = 1.18; 95% confidenceinterval (CI), 1.17-1.20). Among specific components, the largesteffect estimates were found on NO3 (-) (OR= 1.36; 95% CI, 1.35-1.38) followed by OC (OR = 1.23; 95% CI,1.22-1.24), NH4 (+) (OR = 1.22; 95% CI,1.21-1.23), and BC (OR = 1.21; 95% CI, 1.20-1.22). Wealso that found boys, women with a normal or lower prepregnancy bodymass index, and women with irregular or no folic acid supplementationexperienced higher risk of macrosomia associated with PM2.5 exposure.

Automated summary

Prenatal exposure to PM2.5, especially its fuel combustion-related components, is associated with increased risk of macrosomia. This study collected birth records from mainland China and used satellite-based models to estimate concentrations of PM2.5 and its chemical components during pregnancy. The findings show that higher levels of PM2.5 and its components, particularly NO3(-), OC, NH4(+), and BC, are associated with increased risk of macrosomia. Certain subgroups, including boys and women with lower body mass index or irregular folic acid supplementation, are more susceptible to the adverse effects.