Pregnancy outcomes and ethanol cook stove intervention: A randomized-controlled trial in Ibadan, Nigeria

Environ Int. 2018 Feb;111:152-163. doi: 10.1016/j.envint.2017.11.021. Epub 2017 Dec 20.


Background: Household air pollution (HAP) exposure has been linked to adverse pregnancy outcomes.

Objectives: A randomized controlled trial was undertaken in Ibadan, Nigeria to determine the impact of cooking with ethanol on pregnancy outcomes.

Methods: Three-hundred-twenty-four pregnant women were randomized to either the control (continued cooking using kerosene/firewood stove, n=162) or intervention group (received ethanol stove, n=162). Primary outcome variables were birthweight, preterm delivery, intrauterine growth restriction (IUGR), and occurrence of miscarriage/stillbirth.

Results: Mean birthweights for ethanol and controls were 3076 and 2988g, respectively; the difference, 88g, (95% confidence interval: -18g to 194g), was not statistically significant (p=0.10). After adjusting for covariates, the difference reached significance (p=0.020). Rates of preterm delivery were 6.7% (ethanol) and 11.0% (control), (p=0.22). Number of miscarriages was 1(ethanol) vs. 4 (control) and stillbirths was 3 (ethanol) vs. 7 (control) (both non-significant). Average gestational age at delivery was significantly (p=0.015) higher in ethanol-users (39.2weeks) compared to controls (38.2weeks). Perinatal mortality (stillbirths and neonatal deaths) was twice as high in controls compared to ethanol-users (7.9% vs. 3.9%; p=0.045, after adjustment for covariates). We did not detect significant differences in exposure levels between the two treatment arms, perhaps due to large seasonal effects and high ambient air pollution levels.

Conclusions: Transition from traditional biomass/kerosene fuel to ethanol reduced adverse pregnancy outcomes. However, the difference in birthweight was statistically significant only after covariate adjustment and the other significant differences were in tertiary endpoints. Our results are suggestive of a beneficial effect of ethanol use. Larger trials are required to validate these findings.

Keywords: Birth outcomes; Birthweight; Clean cookstove; Ethanol intervention; Gestational age; Randomized controlled trial.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Air Pollutants / analysis
  • Air Pollution, Indoor / analysis
  • Air Pollution, Indoor / prevention & control*
  • Birth Weight
  • Carbon Monoxide / analysis
  • Cooking / methods*
  • Environmental Monitoring
  • Ethanol*
  • Female
  • Gestational Age
  • Household Articles*
  • Humans
  • Infant, Newborn
  • Kerosene
  • Nigeria
  • Particulate Matter / analysis
  • Pregnancy
  • Pregnancy Outcome*
  • Premature Birth / chemically induced
  • Wood
  • Young Adult


  • Air Pollutants
  • Kerosene
  • Particulate Matter
  • Ethanol
  • Carbon Monoxide