Association between air quality index during pregnancy and small for gestational age

Objective To examine the association between air quality index during pregnancy and small for gestational age.

Methods A prospective birth cohort study was conducted in a hospital in Guangzhou from 2017 to 2020. The general information of pregnant women was collected using a questionnaire. Air quality index (AQI) was calculated using daily air pollution exposure during the first, second, and third trimesters and the whole pregnancy. A logistic regression model was used to evaluate the association between AQI and small for gestational age. The scores and quartiles of AQI were included in the model.

Results A total of 5 352 mother-neonate pairs were enrolled. After adjusting for potential confounding variables, the average AQI score in the second trimester was negatively associated with small for gestational age. High AQI during the first trimester (Q4 vs. Q1) was associated with an increased risk of small for gestational age (odds ratio: 1.441, 95% confidence interval: 1.012-2.056).

Conclusion Exposure to high level of air pollution during early pregnancy may affect fetal growth.