Effects of a 500-day LPG cookstove and fuel intervention delivered during gestation and infancy on height-for-age (HAZ) and stunting at ages 2, 3, 4 and 5 years: findings from a follow-up study of the multi-country HAPIN trial
Year: 2026
Type: preprint
Abstract: Objective Reducing household air pollution exposure during gestation and infancy may have longer-term benefits for child linear growth. We examined whether a liquefied petroleum gas (LPG) cookstove and fuel intervention delivered during gestation and infancy could improve height-for-age Z scores (HAZ) and reduce the risk of stunting at ages 2–5 years in India, Rwanda, and Guatemala. Materials and method The Household Air Pollution Intervention Network (HAPIN) was a randomized controlled trial that enrolled ∼3200 pregnant women across Guatemala, India, Peru, and Rwanda. Women in the intervention group received an LPG cookstove and free fuel during pregnancy and until the infant reached 12 months of age. Following the HAPIN trial, we continued following children in Guatemala, India, and Rwanda (N=2169) and measured child height at ages 2, 3, 4, and 5 years (HAPIN 2.0). As prespecified in the study protocol, we used mixed-effects models, as well as linear and log-binomial regression, within the intention to treat (ITT) framework, to evaluate the intervention’s effect on HAZ and stunting. Subgroup analyses were performed to assess effect modification by child sex, maternal height, and intervention country. Results The intervention reduced gestational exposures to particulate matter (PM 2.5 : 80.7 vs 117.5 µg/m³), carbon monoxide (CO: 1.3 vs 2.0 ppm), and black carbon (BC: 8.6 vs 12.1 µg/m³) and infancy exposures (PM 2.5 : 36.9 vs 113.2 µg/m³; CO: 0.60 vs 2.2 ppm). Post-trial PM 2.5 exposure were similar between arms: 99.9 vs 98.7 µg/m³. We found no statistically significant effect of the intervention on repeated measures of HAZ (β = -0.06, 95% CI: -0.16, 0.03 p=0.204), annual HAZ, stunting, nor severe stunting at any age during the follow-up. There was no statistically significant effect modification by subgroups. Conclusion Despite substantial reductions in air pollution exposures during the trial, the LPG intervention did not improve growth or reduce stunting risk from ages 2 through 5 years in this multi-country cohort. These findings, consistent with prior results of the lack of effects on growth through 12 months, provide additional evidence that a clean cooking intervention alone may not be sufficient to address childhood stunting in low-resource settings. Future exposure-response analyses will supplement these ITT analyses. Trial registration ClinicalTrials.gov NCT02944682 Author summary Why was this study done? Household air pollution (HAP) from cooking with biomass fuels has been associated with impaired fetal and child growth in low-and middle-income countries (LMICs). Earlier trials of clean cooking interventions delivered during pregnancy and infancy showed reductions in exposure to HAP but had no impact on child stunting or height-for-age z-scores at 1 year of age It remains unknown whether an intervention with a liquefied petroleum gas (LPG) cookstove and clean fuel that substantially reduces household air pollution exposure during pregnancy and infancy has longer-term effects on growth and stunting in later childhood, such as at ages 2 to 5 years. did the researchers do and find? We conducted a follow-up assessment of children who had been enrolled in the Household Air Pollution Intervention Network (HAPIN), a randomized controlled trial of an LPG cooking intervention, and compared height-for-age, stunting, and severe stunting between the intervention and control groups from ages 2 to 5 years in Guatemala, India, and Rwanda. We found no statistically significant effects of the intervention on repeated measures of HAZ or on annual HAZ, stunting, or severe stunting at any age, and no statistically significant effect modification by subgroups. What do these findings mean? Reducing household air pollution during pregnancy and infancy alone may not be sufficient to have effects on child linear growth through 5 years of age. The importance of the timing and duration of HAP exposure reductions for later child growth remains uncertain, and future exposure-response analyses could supplement these ITT findings. The main limitation of this study is loss to follow-up; children with repeated outcome measurements at all follow-up visits from 24 through 60 months represented 74% of the initially enrolled cohort.
Source: medRxiv
Authors: Md Abul Kalam, Sheela S. Sinharoy, Kyle Steenland, Lisa M. Thompson, Anaite Diaz-Artiga, John P. McCracken, Kalpana Balakrishnan, Vigneswari Aravindalochanan, Sarada Garg, Ghislaine Rosa, Florien Ndagijimana, Shirin Jabbarzadeh, Michael Johnson, Ajay Pillarisetti, Katie Kearns, Amy E. Lovvorn, Usha Ramakrishnan, Jennifer Peel, Thomas F Clasen, HAPIN Investigators
Institutions: Emory University, University of California, San Francisco, Universidad del Valle de Guatemala, University of Georgia, Sri Ramachandra Institute of Higher Education and Research, University of Liverpool, Berkeley Air Monitoring Group (United States), University of California, Berkeley, Colorado State University
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223151795