Nearly one million stillbirths a year are attributable to air pollution, according to a first global study on the subject. She estimates that nearly half of stillbirths are due to exposure to particles smaller than 2.5 microns (PM2.5), mostly produced by burning fossil fuels.

The study looked at 137 countries in Asia, Africa and Latin America, where 98% of stillbirths occur. Dirty air was already known to increase the risk of stillbirth, but the study is the first to estimate the number of fetal deaths. The work is based on data from over 45,000 stillbirths and live births.

Unicef: “Neglected tragedy”

UNICEF, the United Nations Children’s Fund, had stillbirths in a 2020 report as one “neglected tragedy“ appointed. Given the severe impact of stillbirth on mothers and their families, it is important to take action to prevent it to promote women’s health and equality, say the scientists behind the new study epidemiological.

they did not examine How? ‘Or’ What However, small particle pollution is causing stillbirths following a revelation in October that showed toxic air pollution particles were found in the lungs and brains of fetuses. Air pollution particles were first detected in the placenta in 2018. At that time it was already known that dirty air was strongly correlated with increased miscarriages, premature births, low birth weight, birth and brain development disorders.

Meet WHO goals

“Meeting World Health Organization air quality targets could prevent significant number of stillbirths“according to scientists led by Dr. Tao Xue of Peking University in China. “Current efforts to prevent stillbirth focus on improving medical care, but compared to clinical risk factors, environmental factors are generally overlooked.“

And further: “Clean air measures taken in some countries, such as China, can prevent stillbirths. In addition, personal protective measures against air pollution, such as wearing masks, installing air purifiers and preventing exposure to air pollution, for example, could also protect vulnerable pregnant women.“

Pakistan, India, Nigeria

for interior Nature Communication published study used data on stillbirth and air pollution between 1998 and 2016 in 54 low- and middle-income countries (LMICs), including Pakistan, India and Nigeria. Using these data, the number of stillbirths attributable to PM2.5 exposure in the 137 low- and middle-income countries was estimated, taking into account that the impact of polluted air is more important in older mothers.

Virtually all mothers in the study were exposed to PM2.5 levels above the current WHO guideline of 5 micrograms per cubic meter (μg/m3). In 2015, 2.09 million stillbirths were recorded in the countries studied, of which 950,000 (45%) were due to exposure above 5 μg/m3, according to the study.

Less air pollution in China

The WHO guideline value for PM2.5 was 10 μg/m3 by 2021; 99% of mothers in the study were exposed to higher levels of polluted air. This has been linked to 830,000 stillbirths, or 40% of the total, according to the study. The proportion of stillbirths attributed to PM2.5 pollution was particularly high in Pakistan, India, Nigeria and China. Overall, the researchers found that an increase in PM2.5 exposure of around 10 µg/m3 was associated with an 11% increased risk of stillbirth.

The total number of stillbirths increased from 2.31 million in 2010 to 1.93 million in 2019. The researchers explained that the reduction in air pollution in some countries, e.g. B. in China, could be a major reason for this decline. They estimated that reducing air pollution to 10 ug/m3 today could prevent 710,000 stillbirths per year. “Since everyone is exposed to air pollution, it is one of the biggest contributing factors to stillbirths worldwide.“Xue said.

Irreversible embryonic damage

It is not yet known exactly how air pollution can cause stillbirths. However, the researchers explained that the polluting particles that cross the placenta “irreversible embryonic damage“ and could also damage the placenta itself. Air pollution could also limit the ability of the mother’s body to supply oxygen to the fetus.

The researchers found that while the number of stillbirths is falling globally, there is no reduction in about half of the low- and middle-income countries studied. They found that stillbirth rates declined more slowly than under-five mortality rates. “This suggests that efforts to promote maternal health are uneven across different adverse outcomes and that stillbirth interventions are inadequate.“according to the researchers.

Professor Gregory Wellenius, director of the Center for Climate and Health at Boston University in the US, who was not involved in the study, said: “This study is new and shows that at current levels, air pollution contributes to a significant number of stillbirths worldwide. Health impact assessments like this are always based on a number of important assumptions. Although the proportion of stillbirths that could be prevented by drastically reducing PM2.5 levels is uncertain, the study adds to the body of scientific evidence showing that reducing air pollution improves the health of babies. people around the world, especially those most at risk.“.