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
- 1Emory University School of Medicine
Abstract
ObjectiveReducing 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 methodThe 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 interventions effect on HAZ and stunting. Subgroup analyses were performed to assess effect modification by child sex, maternal height, and intervention country.
ResultsThe intervention reduced gestational exposures to particulate matter (PM2.5: 80.7 vs 117.5 {micro}g/m3), carbon monoxide (CO: 1.3 vs 2.0 ppm), and black carbon (BC: 8.6 vs 12.1 {micro}g/m3) and infancy exposures (PM2.5: 36.9 vs 113.2 {micro}g/m3; CO: 0.60 vs 2.2 ppm). Post-trial PM2.5 exposure were similar between arms: 99.9 vs 98.7 {micro}g/m3. We found no statistically significant effect of the intervention on repeated measures of HAZ ({beta} = -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.
ConclusionDespite 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 registrationClinicalTrials.gov NCT02944682
Author summaryO_ST_ABSWhy was this study done?C_ST_ABSO_LIHousehold air pollution (HAP) from cooking with biomass fuels has been associated with impaired fetal and child growth in low-and middle-income countries (LMICs). C_LIO_LIEarlier 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 C_LIO_LIIt 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. C_LIO_LIdid the researchers do and find? C_LIO_LIWe 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. C_LIO_LIWe 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. C_LI
What do these findings mean?O_LIReducing household air pollution during pregnancy and infancy alone may not be sufficient to have effects on child linear growth through 5 years of age. C_LIO_LIThe 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. C_LIO_LIThe 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. C_LI
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BibTeX
@misc{kalam2026effects,
title = {{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}},
author = {M. A. Kalam and S. S. Sinharoy and K. Steenland and L. M. Thompson and A. Diaz-Artiga and J. P. McCracken and K. Balakrishnan and V. Aravindalochanan and S. Garg and G. Rosa and F. Ndagijimana and S. Jabbarzadeh and M. Johnson and A. Pillarisetti and K. Kearns and A. E. Lovvorn and U. Ramakrishnan and J. Peel and T. F. Clasen},
howpublished = {medRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.16.26365712},
url = {https://www.medrxiv.org/content/10.64898/2026.10.16.26365712v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - 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
AU - M. A. Kalam
AU - S. S. Sinharoy
AU - K. Steenland
AU - L. M. Thompson
AU - A. Diaz-Artiga
AU - J. P. McCracken
AU - K. Balakrishnan
AU - V. Aravindalochanan
AU - S. Garg
AU - G. Rosa
AU - F. Ndagijimana
AU - S. Jabbarzadeh
AU - M. Johnson
AU - A. Pillarisetti
AU - K. Kearns
AU - A. E. Lovvorn
AU - U. Ramakrishnan
AU - J. Peel
AU - T. F. Clasen
PY - 2026
DA - 2026/10/16
PB - medRxiv
DO - 10.64898/2026.10.16.26365712
UR - https://www.medrxiv.org/content/10.64898/2026.10.16.26365712v1
AB - ObjectiveReducing 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 methodThe 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 interventions effect on HAZ and stunting. Subgroup analyses were performed to assess effect modification by child sex, maternal height, and intervention country. ResultsThe intervention reduced gestational exposures to particulate matter (PM2.5: 80.7 vs 117.5 {micro}g/m3), carbon monoxide (CO: 1.3 vs 2.0 ppm), and black carbon (BC: 8.6 vs 12.1 {micro}g/m3) and infancy exposures (PM2.5: 36.9 vs 113.2 {micro}g/m3; CO: 0.60 vs 2.2 ppm). Post-trial PM2.5 exposure were similar between arms: 99.9 vs 98.7 {micro}g/m3. We found no statistically significant effect of the intervention on repeated measures of HAZ ({beta} = -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. ConclusionDespite 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 registrationClinicalTrials.gov NCT02944682 Author summaryO_ST_ABSWhy was this study done?C_ST_ABSO_LIHousehold air pollution (HAP) from cooking with biomass fuels has been associated with impaired fetal and child growth in low-and middle-income countries (LMICs). C_LIO_LIEarlier 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 C_LIO_LIIt 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. C_LIO_LIdid the researchers do and find? C_LIO_LIWe 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. C_LIO_LIWe 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. C_LI What do these findings mean?O_LIReducing household air pollution during pregnancy and infancy alone may not be sufficient to have effects on child linear growth through 5 years of age. C_LIO_LIThe 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. C_LIO_LIThe 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. C_LI
ER -