Mothers exposed to household air pollution during pregnancy are more likely to give birth to infants with impaired lung function, which may subsequently increase the infant’s risk for pneumonia within the first year of life, according to a study published in the American Journal of Respiratory and Critical Care Medicine.
A total of 1414 nonsmoking pregnant women from the cluster-randomized Ghana Randomized Air Pollution and Health Study were included in this analysis. Participants were enrolled in the study prior to 24 weeks’ gestation and agreed to include their infant in a pulmonary function assessment (n=404). Investigators evaluated prenatal household air pollution exposure using serial maternal carbon monoxide personal exposure measurements.
Associations between average prenatal carbon monoxide level and infant lung function were assessed at age 30 days. In addition, the researchers assessed associations between prenatal pollution exposure and physician-assessed pneumonia (ie, cough or breathing difficulties) in infants at up to 12 months of age.
In the multivariable linear regression analysis adjusted for child length, sex of infant, weight, and age at lung function assessment, the investigators found significant associations between increased average prenatal carbon monoxide level (per 1 ppm increase in average prenatal carbon monoxide) and reduced time to peak tidal expiratory flow to expiratory time (P =.01), increased respiratory rate (P =.02), and increased minute ventilation (P =.05).
Female infants were more susceptible than male infants, particularly with regard to time to peak tidal expiratory flow to expiratory time (P =.05), respiratory rate (P =.01), minute ventilation (P =.01), and passive respiratory compliance normalized for body weight (P =.01). At 30 days of age, an increased respiratory rate was associated with a significantly greater chance of pneumonia (risk ratio, 1.02; 95% CI, 1.00-1.04; P =.03) as well as severe pneumonia (risk ratio, 1.04; 95% CI, 1.00-1.08; P =.04) within the first year of life.
The inclusion of patients residing only in rural Ghana as well as the lack of long-term data on infants’ lung function are limitations of the analysis.
“Given previously established associations between early life lung function and respiratory morbidity across the life course,” the researchers concluded, “these findings support the urgent need for reductions in exposure to [household air pollution], including during the prenatal period.”
Lee AG, Kaali S, Quinn A, et al. Prenatal household air pollution is associated with impaired infant lung function with sex-specific effects: evidence from GRAPHS, a Cluster Randomized Cookstove Intervention Trial [published online September 26, 2018]. Am J Respir Crit Care Med. doi:10.1164/rccm.201804-0694OC