Association Between PM_2.5 Exposure And Congenital Heart Disease In Fuzhou:A Crossover Study With 375 Cases Of Congenital Heart Diseases

Objective and BackgroundIn February 2012,the State Council agreed to issue the Ambient Air Quality Standards,which contains PM_2.5 monitoring targets.Maternal exposure to air pollution was associated with congenital heart disease（CHD）,but the results were inconsistent.The study aims to investigate the basic situation,confounding factors and trend of congenital heart disease in Fuzhou during 2014-2018 to find the association between PM_2.5 exposure and congenital heart disease during pregnancy,and to explore the prevention strategies to reduce the occurrence of congenital heart disease.MethodsWe collected maternal information who delivered baby with congenital heart diseases from two hospitals in Fuzhou during 2014-2018.This study described the composition ratio and gender of perinatal infants with congenital heart diseases in the two hospitals.The difference of gender,maternal age,maternal occupation and gestational season between the control women and women with their babies with congenital heart diseases was analyzed using Chi-square test.The maternal PM_2.5exposure was evaluated using the monitoring data from Fujian Province Environmental Supervision Center.The exposure-response relationship between PM_2.5 exposure at different stages of early pregnancy and congenital heart diseases was analyzed by case-cross design.Results1.From January 1,2014 to December 31,2018,the concentration of major air pollutants in Fuzhou showed a downward trend.There was a strong correlation between the main pollutants in the air.The PM_2.5 concentration was analyzed in time series and showed obvious seasonal fluctuations and periodic changes.The concentration of PM_2.5decreased in summer and autumn and increased in winter and spring.2.From January 1,2014 to July 31,2018,the ventricular septal defect had a highest ratio.The occurrence of congenital heart diseases had no significant difference in gender,maternal age,maternal occupation and gestational season.3.375 cases were grouped according to the highest exposure level in each of the three exposure periods.It was found that the incidence of congenital heart diseases was increased with PM_2.5 exposure in the group 1.When the first,second and third periods PM_2.5.5 concentration was>34.5μg/m³,the incidence of CHD was highest.When the second period PM_2.5.5 concentration was>34.5μg/m³ and the first and third period PM_2.5concentration was 28.0-34.5μg/m³,the incidence of CHD was highest.When the first and third period PM_2.5.5 concentration was 21.0-28.0μg/m³,and the second period PM_2.5concentration was<21.0μg/m³,the incidence of CHD was highest.The incidence of congenital heart disease didn’t always increase with the increase of the PM_2.5concentration in each period.4.During the 3-8 weeks after conception,the odds ratios（95%CI）were 0.8442（0.7145⁰.9975）and 0.7668（0.6134⁰.9586）with each 10μg/m³ increase in PM_2.5 in the entire group and ventricular septal defect subgroup（P<0.05）.There was a negative correlation between the PM_2.5 exposure and incidence of congenital heart disease.Conclusion（1）This study preliminarily shows that there may be a"non-linear"relationship between PM_2.5 exposure and the occurrence of congenital heart disease.During 3-8weeks after conception,the odds ratios of congenital heart disease and ventricular septal defect were decreased with increase in PM_2.5 levels.（2）It is not clear why there is a"non-linear"relationship between PM2.5 exposure and congenital heart diseases.Congenital heart disease is one of the main causes of serious diseases and infant deaths.Reducing PM_2.5 exposure during pregnancy is important for the prevention of adverse pregnancy outcomes.