Preterm births are one of the leading causes of death among infants worldwide, with an estimated 15 million babies born too early each year.

Preterm birth is defined as a birth that occurs before 37 completed weeks of gestation, and it is associated with substantial short- and long-term morbidity and mortality, including respiratory distress syndrome, necrotizing enterocolitis, and cerebral palsy.

What is air pollution?

Air pollution is the presence of substances in the air that are harmful to human health or the environment.

These substances, which are called pollutants, come from a variety of sources, including motor vehicle exhaust, industrial emissions, and wildfires. Air pollution can have many negative health effects, including respiratory diseases, heart disease, stroke, and cancer. Exposure to air pollution during pregnancy has also been linked to adverse reproductive outcomes, including preterm birth.

Link between air pollution and preterm births

A growing body of evidence suggests that exposure to air pollution during pregnancy is associated with an increased risk of preterm birth.

A recent systematic review and meta-analysis of 34 studies found that exposure to air pollution was significantly associated with an increased risk of preterm birth, with an estimated 10% increase in the risk of preterm birth for every 10 μg/m3 increase in fine particulate matter (PM2.5) exposure. Other studies have found similar associations between air pollution and preterm birth, with some studies reporting stronger associations with exposure to specific pollutants such as nitrogen dioxide (NO2) and ozone (O3).

How does air pollution affect pregnancy?

It is not entirely clear how air pollution affects pregnancy, but there are several hypotheses. One hypothesis is that air pollution causes inflammation, oxidative stress, and damage to the placenta, which can lead to preterm birth.

Another hypothesis is that air pollution affects the development of the fetal lungs and other organs, which can also lead to preterm birth. Exposure to air pollution during pregnancy has also been linked to an increased risk of low birth weight, another adverse reproductive outcome.

Global health concern

Preterm birth and air pollution are both significant global health concerns, and their intersection is particularly troubling.

The World Health Organization (WHO) estimates that 15 million babies are born preterm every year, with the majority occurring in low- and middle-income countries. Similarly, air pollution is a major health concern, particularly in urban areas of low- and middle-income countries, where exposure levels are often high due to a lack of regulation and enforcement and poor urban planning.

What can be done?

Reducing exposure to air pollution during pregnancy is an important public health goal, but it requires a multi-pronged approach.

Some strategies that have been suggested include:

Regulating industrial emissions and vehicle exhaust
Promoting public transportation and active transportation
Improving indoor air quality
Planting trees and vegetation to mitigate the effects of air pollution
Providing education and awareness campaigns to the public

While these strategies are promising, addressing the problem of air pollution requires political will and significant investment. Ultimately, reducing exposure to air pollution during pregnancy will require a concerted effort by governments, industry, and individuals.

Conclusion

The link between air pollution and preterm births is a significant global health concern that requires urgent attention.

With an estimated 15 million preterm births occurring every year, and with air pollution levels continuing to rise in many parts of the world, addressing this problem is critical.

By regulating industrial emissions, promoting public transportation, improving indoor air quality, and planting vegetation to mitigate the effects of air pollution, we can reduce exposure to harmful pollutants and improve the health of pregnant women and their babies.