Prenatal and postnatal household air pollution and longitudinal growth trajectories: results from long-term follow up of the GRAPHS cohort

• The long-term effects of prenatal and postnatal HAP on child growth are unknown. • We leveraged a pregnancy cohort with personal CO and PM 2.5 measurements. • Higher prenatal CO was associated with lower HAZ from 1 through 9 years of age. • Results did not differ by child sex. There is limited evidence on the long-term effects of household air pollution (HAP) exposure during critical developmental windows and longitudinal growth trajectories in childhood. We leveraged a longitudinal pregnancy cohort from rural communities in central Ghana with repeated personal monitoring of prenatal and postnatal carbon monoxide (CO) and fine particulates (PM 2.5 ). Child growth was measured at 1 year of age (n = 919), and annually from age 4 through 9 years (n = 698). Using generalized linear mixed-effects models adjusted for relevant confounders, we quantified separately, the age-specific associations between prenatal and postnatal CO and PM 2.5 , and z-scores of height-for-age (HAZ), weight-for-age (WAZ) and body mass index (BMI)-for-age (BMIZ) in primary models. Secondary models assessed the risk of being in a worse growth category compared with a better category e.g., for HAZ, stunted or at risk of stunting versus normal, or stunted versus at risk or normal). Prenatal CO had the most consistent association with growth. Higher prenatal CO was associated with lower HAZ from age 1 through 9 with peak effect at age 4: adjusted β = −0.08; 95% CI = −0.12, −0.03; p = 0.002 per doubling), and WAZ from 7 through age 9 (peak effect was at age 9: adjusted β = −0.05; 95% CI = −0.09, −0.003; p = 0.04 per doubling). Results were similar for the ordered categories of HAZ and WAZ. Sex did not modify these associations. Higher HAP exposure, as indexed by prenatal CO during critical developmental windows may contribute substantially to long-term poor linear growth throughout childhood.