Association analysis of maternal exposure to air pollution during pregnancy and offspring asthma incidence.

Background: Air pollution has a significant negative impact on human health. Pregnant mothers and children are typical susceptible groups, and environmental exposure has a crucial impact on children's health. We established a childhood asthma cohort to analyze the factors influencing the development of asthma in offspring, with a focus on prenatal exposure to air pollutants. The goal was to explore potential early preventive measures to reduce the incidence of childhood asthma.

Methods: This nested case-control study included mothers who were registered and delivered at Lianyungang Maternal and Child Health Hospital between 2015 and 2018, covering pre-pregnancy, first, second, and third trimesters. Children diagnosed with asthma before the age of four were included in the asthma group. To assess environmental exposure, we gathered data from 29 national and provincial air pollution monitoring stations and 16 meteorological monitoring sites in Lianyungang and surrounding areas. We used spatial interpolation with inverse distance weighting (IDW) to estimate individual exposure to air pollutants, including particulate matter (PM_2.5, PM₁₀), carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃). Univariate and multivariate regression analyses were conducted to examine the association between maternal exposure during pregnancy and the risk of childhood asthma.

Results: A total of 292 mother-child pairs in the asthma group and 1423 mother-child pairs in the healthy control group were included. The second (AOR = 1.04, 95%CI 1.01-1.06) and whole gestation (AOR = 1.06, 95%CI 1.03-1.10) exposure to PM_2.5 was associated with higher odds of childhood-onset asthma. Exposure during the third trimester (AOR = 1.02, 95%CI 1.01-1.03) and whole gestation (AOR = 1.02, 95%CI 1.01-1.04) of PM₁₀ was associated with higher odds of childhood-onset asthma. The first (AOR = 1.06, 95%CI 1.02-1.09) and second (AOR = 0.95, 95%CI 0.92-0.98) trimesters exposure to NO₂ was associated with higher and lower odds of childhood-onset asthma, respectively. SO₂ whole pregnancy exposure (AOR = 1.04, 95%CI 1.01-1.07) was associated with higher odds of childhood-onset asthma.

Conclusions: Exposure to PM_2.5, PM₁₀, and SO₂ during pregnancy can lead to an elevated risk of childhood asthma. Reducing or avoiding exposure to pollutants during pregnancy can reduce the incidence of childhood asthma. We should protect the environment and reduce the harm of environmental pollution to health.