Prenatal air pollution exposure and infant weight trajectories from 3rd trimester to 2 years of age

Abstract

BACKGROUND AND AIM: Prenatal exposure to air pollution is increasingly viewed as harmful to fetal development and leads to childhood obesity. However, few studies have evaluated in utero growth measures and postnatal weight trajectories along a continuum in statistical models. This study aims to evaluate associations between prenatal air pollution and weight trajectories from the 3rd trimester through 2 years of life among infants in the Maternal and Development Risks from Environmental and Social Stressors (MADRES) pregnancy cohort, which comprises a low-income, primarily Hispanic population in Los Angeles, California. METHODS: Fetal weights during the 3rd trimester were abstracted from maternal ultrasound records. Infant weight measures were abstracted from medical records and measured by staff at study visits. Ambient particulate matter ≤2.5 μm and ≤10 μm in diameter (PM2.5 and PM10) concentrations were assigned using spatial interpolation from the regulatory air monitoring stations. Piecewise linear spline models were used to assess non-linear associations between prenatal air pollution exposure and infant weight trajectories. RESULTS: Weight increased most rapidly from 3 months prior to birth through 3 months of age, slowing thereafter. Pregnancy-averaged PM2.5 and PM10 were associated with a slower rate of growth from the 3rd trimester until age 2 years. A one IQR increase in PM2.5 (1.65 ug/m3) and PM10 (7.48 ug/m3) exposure were associated with a 0.28 kg and 0.38 kg lower weight at 2 years of age, respectively. In sex-stratified models, the effects of PM2.5 and PM10 were only significant in females. CONCLUSIONS: Our findings suggest that prenatal exposure to PM2.5 and PM10 could impact infant weight gain trajectories and thus, impact childhood obesity, with potentially more pronounced impacts among females. KEYWORDS: prenatal air pollution, growth trajectory