Maternal exposure to particulate matter during pregnancy and offspring liver function

Air pollution is associated with hepatic dysfunction, but the evidence in the early childhood remains limited. This study aimed to explore the associations between maternal exposure to particulate matter and offspring liver function, as indicated by serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in children aged 1-2 years. Based on the Fujian Birth Cohort Study (FJBCS), a total of 1046 mother-offspring pairs were analyzed in this study. Maternal mean exposures to PM₁, PM_2.5 and PM₁₀ were calculated for the entire gestational period and each of the three trimesters. Linear regression models were used and restricted cubic spline (RCS) models were further applied to explore the exposure-response relationships. Distributed lag models (DLMs) were conducted to examine the weekly associations throughout pregnancy. Results show that positive associations were found between maternal exposure and offspring enzyme levels in the entire pregnancy as well as the second trimester alone. After adjustment, an interquartile range (IQR) increment in PM₁, PM_2.5 and PM₁₀ in the second trimester was associated with increases in ALT by 1.42 (0.82-2.03) U/L, 1.41 (0.77-2.05) U/L, 0.91 (0.35-1.46) U/L, and in AST by 1.64 (1.00-2.29) U/L, 1.56 (0.88-2.23) U/L and 0.80 (0.21-1.39) U/L, respectively. DLM analyses further indicated that the associations were the most pronounced during the second trimester. Our findings suggest that maternal exposure to particulate matter is positively associated with increased levels of ALT and AST in offspring, with the second trimester representing a potentially sensitive period.