Risks of preterm birth and low birth weight and maternal exposure to NO2/PM2.5 acquired by dichotomous evaluation: a systematic review and meta-analysis

No consistent results from past studies have been found on the relationship between the effects of air pollutant exposure, preterm birth (PTB) and low birth weight (LBW) in fetuses. This study aimed to analyze the impact of high concentrations of air pollutants on the health outcomes of fetuses, especially regarding PTB and LBW. This study used keywords related to air pollutants, pregnancy, and birth outcomes, to search the literature within the databases of the Cochrane Library, PubMed, and Embase, which were published as of July 26, 2022. A total of 24 studies were included in this meta-analysis. This meta-analysis revealed that nitrogen dioxide (NO2) exposure throughout pregnancy was associated with an increased risk of PTB. Maternal exposure to PM2.5 (particulate matter sized less than 2.5 mu m) during gestation was associated with the risk of LBW. The findings of this meta-analysis provide an important foundation for evaluating the relationship between exposure of air pollutants and fetal birth outcomes in countries with severe air pollution in the future.

Automated summary

No consistent results have been found in past studies regarding the relationship between air pollutant exposure, preterm birth, and low birth weight in fetuses. This study aimed to analyze the impact of high concentrations of air pollutants on fetal health outcomes, specifically preterm birth and low birth weight. A meta-analysis of 24 studies revealed that exposure to nitrogen dioxide throughout pregnancy was associated with an increased risk of preterm birth, while maternal exposure to PM2.5 during gestation was associated with the risk of low birth weight. These findings provide an important foundation for evaluating the relationship between air pollutant exposure and fetal birth outcomes in countries with severe air pollution in the future.