Effect of Prenatal Exposure to Air Pollution (Particulate Matter and Carbon Monoxide) on Infant Adiposity

Background The environmental pollutants during pregnancy disrupt the developmental processes in foetus and infant with possible lifelong consequences. This article presents the results on effect of prenatal exposure to air pollution on infant adiposity among infants mediated through low birth weight.Methods The study was nested in MAASTHI cohort study. The participants were pregnant women of urban slums of Bangalore and the study was conducted from September 2017 to 2019. Pregnant women residing in urban slums belonging to the age group of 18-45 years with a gestational age of less than 18 weeks with no coexisting illnesses were recruited for the study. We estimated pregnancy period exposure measurements of PM2.5 PM10 and CO for 24 hours during the second and third trimesters. The ambient exposure to PM2.5 PM10 and COnbspwere extracted from the monitoring stations installed by the State Pollution Control Board in Bengaluru. Pregnant mothers also completed a detailed questionnaire to provide information on covariates related to household characteristics socio-demographics and obstetric history. The participants were followed up at birth at six months and one year after birth. We recorded infantrsquos weight length circumferences and skinfold thicknesses at each follow up visit. The association between exposure measurements and adiposity markers was estimated using a linear regression model controlling for potential confounder variables.Results The study recruited 519 pregnant women and could track 362 80 children at six months against the intended 449 children. Among these 160 children had complete anthropometric data while the remaining children were not considered due to COVID-19 pandemic. We observed that the mean values of motherrsquos weight height pregnancy exposure to indoor PM2.5 and PM10 were higher among children with weight for age z-scores whereas both pregnancy exposure to indoor and ambient CO were lower. We found a statistically significant association between pregnancy exposure to particulate matter and weight for age Z-score and triceps skinfold thickness.Conclusion The findings of the study suggest that air pollution exposure during pregnancy may be associated with infant obesity particularly with weight and skinfold thickness at six months. The findings implied that pregnancy exposure to air pollution has a lasting effect on growth after birth. Further large scale and long term follow up studies are needed to better understand the biological mechanisms linking air pollution exposure and its role in childrsquos risk for obesity.