Maternal air pollution exposure and neonatal congenital heart disease: A multi-city cross-sectional study in eastern China.

Objective: To examine the association between air pollution and neonatal congenital heart disease (CHD), and evaluate the cumulative burden of CHD attributed to above certain level for ambient air pollution exposure.

Methods: We identified newborns who were diagnosed as CHD by echocardiography in Network Platform for Congenital Heart Disease (NPCHD) from January 2019 to December 2020 in 11 cities eastern China. The exposure lag response relationship between air pollutants (PM, PM, SO, NO, CO, and O) concentration and CHDs was calculated by the distributed lag nonlinear model (DLNM). We further calculated the cumulative risk ratios (CRRs) of each air pollutant above reference concentrations on CHDs.

Results: A total of 5904 CHDs from 983, 523 newborns were enrolled in this study. A 10 μg/m increase in PM, PM, SO, NO, CO and O exposure was associated with an increased risk of higher CHD incident RR = 1.025, 95% CI: 1.016-1.038 for PM in the third trimester, RR = 1.001, 95% CI: 1.000-1.002 for PM in the third trimester, 1.020, 95%CI: 1.004-1.036 for NO in the third trimester, RR = 1.001, 95%CI: 1.000-1.002 for O in the first trimester, all P value < 0.05). Cumulative effect curves of PM, PM, SO, NO, CO, and O were observed as sub-linear with a maximum of 1.876 (95%CI:1.220-2.886), 1.973 (95%CI:1.477,2.637), 2.169 (95%CI:1.347-3.493), 2.902 (95%CI:1.859-4.530), 1.398 (95%CI:1.080-1.809), 2.691 (95%CI:1.705-4.248), respectively. Significant associations were observed for air pollutants and CHDs in cities with higher average education years and babies concepted in cold season.

Conclusions: Our findings could provide growing evidence regarding the adverse health effects of air pollution on CHD, thereby strengthening the hypothesis that air pollutants have harmful impacts on cardiac development. Further studies are needed to verify the associations.