Prenatal air pollution exposure could lead to growth delays

Air pollution exposure during pregnancy may result in physical growth delays after birth, according to a new study by the Barcelona Institute for Global Health (ISGlobal). Researchers added that the growth effects may be lasting and could require follow-up as the child ages.

According to the World Health Organization (WHO), nearly 90% of people worldwide breathe polluted air. Prenatal air pollution exposure is known to cause significant health risks in children, such as lower birth weight and adverse respiratory outcomes. However, little research has evaluated its impact on postnatal and early childhood growth.

The comprehensive Spanish study, published in Environmental International, was conducted to expand current knowledge of prenatal air pollution exposure and explore its associations with physical growth and cardio-metabolic risk factors in postnatal and early childhood.

Researchers used data from the Environment and Childhood Project, a Spanish network of birth cohorts known as Infancia y Medio Ambiente (INMA), to analyze 2,765 pregnant mother-child dyads (N=1,724) in the first trimester of pregnancy. Women were recruited between 2003 and 2008. First-trimester nitrogen dioxide (NO₂) and fine particles (PM_2.5) exposure levels were estimated. Child height, weight, waist circumference, blood pressure, and lipids were measured at 4 years, and body mass index (BMI) trajectories were recorded from birth to 4 years.

The results of this study of many growth and cardio-metabolic risk-related outcomes suggest that increased PM_2.5 exposure in the first trimester was associated with decreased weight and BMI. Higher NO₂ and PM_2.5 exposure was associated with a reduced risk of accelerated BMI trajectory.

The authors concluded that air pollution exposure during pregnancy may result in physical growth delays in the early years after birth. They also noted that these adverse effects were lasting after birth and could require follow-up in later years of childhood.

The study and its findings ultimately highlight that pregnant women should be considered a priority when creating public health policies.

References:

• Fossati, S., Valvi, D., Martinez, D., Cirach, M., Estarlich, M., Fernández-Somoano, A., Guxens, M., Iñiguez, C., Irizar, A., Lertxundi, A., Nieuwenhuijsen, M., Tamayo, I., Vioque, J., Tardón, A., Sunyer, J. and Vrijheid, M., 2020. Prenatal air pollution exposure and growth and cardio-metabolic risk in preschoolers. Environment International, May 1, 2020. Epub ahead of print. doi: 10.1016/j.envint.2020.105619