Effects of maternal exposure to ambient air pollution on newborn telomere length

Telomere length (TL) is considered as a surrogate of biological aging and has been related to aging-related diseases. The initial setting of newborn TL has important implications for telomere dynamics in adulthood, and is affected by the intrauterine environment. However, the effects of prenatal air pollution exposure on the initial setting of newborn TL are poor understood.

We aimed to explore the trimester-specific relationships between maternal air pollution exposure and newborn TL.

Between November 2013 and March 2015, a total of 762 mother-newborn pairs were recruited in a birth cohort study in Wuhan, China. Relative cord blood TL was assessed using quantitative real-time polymerase chain reaction. Maternal exposures to PM_2.5, PM₁₀, SO₂, CO, and NO₂, were determined using spatial-temporal land use regression models. Multiple informant models were applied to explore the trimester-specific associations of maternal air pollution exposure with cord blood TL.

In single-pollutant models, a 10 μg/m³ increase in PM_2.5, PM₁₀, SO₂, and a 100 μg/m³ increase in CO during the third trimester were related to 3.71% (95% confidence interval [CI]: -6.06%, -1.30%), 3.24% (95% CI: -5.29%, -1.14%), 11.07% (95% CI: -18.86%, -2.53%), and 3.67% (95% CI: -6.27%, -1.00%) shorter cord blood TL, respectively. The inverse relationships between exposures to PM_2.5, PM₁₀, SO₂, and CO during the third trimester and cord blood TL were more evident in male infants. In multi-pollutant models, exposures to PM_2.5 and PM₁₀ during the third trimester were both related to shorter cord blood TL, but not SO₂ and CO.

This study suggested that maternal exposures to PM_2.5, PM₁₀, CO, and SO₂ during the third trimester were related to shorter newborn TL, which highlights the importance of improving air quality in favor of subsequent health in later life of newborns.