Prenatal and Postnatal Household Air Pollution Exposure and Infant Growth Trajectories: Evidence from a Rural Ghanaian Pregnancy Cohort

BACKGROUND: The exposure-response association between prenatal and postnatal household air pollution (HAP) and infant growth trajectories is unknown. OBJECTIVES: To evaluate associations between prenatal and postnatal HAP exposure and stove interventions on growth trajectories over the first year of life. METHODS: The Ghana Randomized Air Pollution and Health Study enrolled n = 1,414 pregnant women at <24 wk gestation from Kintampo, Ghana, and randomized them to liquefied petroleum gas (LPG), improved biomass, or open fire (control) stoves. We quantified HAP exposure by repeated, personal prenatal and postnatal carbon monoxide (CO) and, in a subset, fine particulate matter [PM with an aerodynamic diameter of <= 2.5 lm (PM2.5)] assessments. Length, weight, mid-upper arm circumference (MUAC) and head circumference (HC) were measured at birth, 3, 6, 9, and 12 months; weight-for-age, length-for-age (LAZ), and weight-for-length z (WLZ)-scores were calculated. For each anthropometric measure, we employed latent class growth analysis to generate growth trajectories over the first year of life and assigned each child to a trajectory group. We then employed ordinal logistic regression to determine associations between HAP exposures and growth trajectory assignments. Associations with stove intervention arm were also considered. RESULTS: Of the 1,306 live births, 1,144 had valid CO data and anthropometric variables measured at least once. Prenatal HAP exposure increased risk for lower length [CO odds ratio (OR) = 1.17, 95% CI: 1.01, 1.35 per 1-ppm increase; PM2.5 OR = 1.07, 95% CI: 1.02, 1.13 per 10-mu g/m(3) increase], lower LAZ z-score (CO OR = 1.15, 95% CI: 1.01, 1.32 per 1-ppm increase) and stunting (CO OR = 1.25, 95% CI: 1.08, 1.45) trajectories. Postnatal HAP exposure increased risk for smaller HC (CO OR = 1.09, 95% CI: 1.04, 1.13 per 1-ppm increase), smaller MUAC and lower WLZscore (PM2.5 OR = 1.07, 95% CI: 1.00, 1.14 and OR = 1.09, 95% CI: 1.01, 1.19 per 10-mu g/m(3) increase, respectively) trajectories. Infants in the LPG arm had decreased odds of having smaller HC and MUAC trajectories as compared with those in the open fire stove arm (OR = 0.58, 95% CI: 0.37, 0.92 and OR = 0.45, 95% CI: 0.22, 0.90, respectively). DISCUSSION: Higher early life HAP exposure (during pregnancy and through the first year of life) was associated with poorer infant growth trajectories among children in rural Ghana. A cleaner-burning stove intervention may have improved some growth trajectories.

Automated summary

In rural Ghana, prenatal and postnatal household air pollution (HAP) exposure can affect infant growth trajectories, while cleaner-burning stove intervention may help improve some growth trajectories.