UCSF

BACKGROUND: Early Child Development (ECD) encompasses physical, cognitive, social, and emotional changes during childhood. Air pollution exposure has been associated with ECD delays. The Household Air Pollution Intervention Network (HAPIN) randomized controlled trial evaluated the health effects of a liquefied petroleum gas cookstove and fuel intervention during pregnancy and infancy. Here we present the intervention effect and exposure-response relationship between fine particulate matter (PM_2.5) and ECD. METHODS: The HAPIN trial enrolled 3195 pregnant women in rural Guatemala, Peru, India, and Rwanda. ECD was assessed at 12 months of infant age using the Caregiver Reported Early Development Instruments (CREDI). Personal 24-hr PM_2.5 exposure was measured from baseline through 12 months. Linear regression analyses were conducted to evaluate intervention effects on overall and domain-specific CREDI scores and exposure-response relationships between prenatal and postnatal PM_2.5 and infant development. RESULTS: Of 3061 live births, 2446 (79.9%) had valid CREDI assessments at 12 months. Despite substantial reductions in personal PM_2.5 exposures, the intervention did not have a significant effect on the overall age-standardized ECD score (adjusted mean difference 0.033, 95% CI: -0.023 to 0.088) or on sub-domain age-standardized scores. Subgroup analyses revealed that the intervention improved CREDI scores among infants whose mothers received the intervention before 18 weeks of gestation, and among female infants. No clear associations were observed between PM_2.5 exposure and CREDI scores at 12 months. DISCUSSION: While the LPG stove intervention did not affect ECD outcomes, variations in timing and sex-specific differences may play a role in shaping intervention effectiveness, similar to findings we previously reported for birth outcomes.