Noise exposure during pregnancy associated with larger embryonic size

Greater exposure to noise is associated with larger embryonic size in early pregnancy, according to a study in which the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa" Foundation, has participated. The research, published in Environment International, analysed the association between exposure to noise from road, air, rail and industrial traffic and embryonic and foetal growth.

Several studies have examined the association between exposure to environmental noise during pregnancy, mainly from aircraft and road traffic, and birth outcomes, including birth weight, preterm birth and small-for-gestational age birth. However, no previous study has looked at the association between exposure to environmental noise during pregnancy and embryo size and foetal growth.

This study involved 7,947 pregnant women from the Generation R study, a prospective cohort from the city of Rotterdam in the Netherlands.

Adverse exposure affects embryo size

The research team found that higher noise exposure during pregnancy was associated with greater embryo length in early pregnancy, while no association was found with fetal growth from mid-pregnancy to birth or with adverse birth outcomes. The results also suggested that exposure to green space was associated with smaller embryonic size, and that this was partly due to a reduction of noise exposure.

“This is not the first time that adverse exposures, such as noise, have been associated with larger embryonic size,” says Mònica Guxens, ISGlobal researcher and senior author of the study. The mechanisms by which this might happen are still unknown, although it has been hypothesised that the accelerated growth in the first trimester could be an immediate survival mechanism for the embryo to adapt to adverse intrauterine conditions.

"In any case, it is clear that further research is needed to confirm and better understand the potential effects of noise exposure during pregnancy on embryonic growth, including other urban environmental exposures such as traffic-related air pollution and nature,” the researcher concludes.

Imagen: Unsplash

Reference: Graafland N., Essers E., Posthumus A., Gootjes D., Ambrós A., Steegers E., Guxens M. Exposure to outdoor residential noise during pregnancy, embryonic size, fetal growth, and birth outcomes. Environment International. Volume 171, January 2023, 107730. https://doi.org/10.1016/j.envint.2023.107730