Research shows air pollution can reduce the chance of a live birth after IVF by 38%

Exposure to air pollution can significantly reduce the chances of having a live child after IVF, research raises concerns about the health effects of toxic air on fertility.

Exposure to pollutants has previously been linked to increased rates of miscarriage and preterm birth, and microscopic black carbon particles have been shown to travel through the bloodstream to the ovaries and placenta. The latest work suggests that the impact of pollution begins before conception by disrupting egg development.

“We found that the chance of having a baby after frozen embryo transfer was more than a third lower for women exposed to the highest levels of particulate air pollution before egg collection, compared with those exposed to the lowest levels,” said Dr Sebastian Leathersich, a fertility specialist and gynaecologist from Perth who will present the findings on Monday at the annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam.

Air pollution is one of the greatest threats to human health and is estimated by the World Health Organization (WHO) to be the cause of 6.7 million dead in 2019. It has been shown that microscopic soot particles enter the bloodstream from the lungs and are carried to every organ in the body, increasing the risk of heart disease, stomach cancers And DementiaThe infection has also been linked to a decline in intelligence.

“Pollution is damaging to almost every aspect of human health, and it doesn’t surprise me that reproductive health is being affected,” Leathersich said. “I hope these findings will underscore the urgency of the situation: that climate change poses a serious and immediate threat to human reproductive health, even at so-called safe levels.”

The study analysed fertility treatments in Perth over an eight-year period, including 3,659 frozen embryo transfers from 1,836 patients, and tracked whether outcomes were associated with levels of fine particulate matter, known as PM10. The overall live birth rate was around 28% per transfer. However, success rates varied according to exposure to pollutants in the two weeks prior to egg collection. The chance of a live birth decreased by 38% when comparing the highest quartile of exposure with the lowest quartile.

“These findings suggest that contamination negatively impacts egg quality, not just early pregnancy. This is a distinction that has not been reported before,” Leathersich said.

The team now plans to study cells directly to understand why pollutants have a negative effect. Previous work has shown that the microscopic particles can damage DNA and cause inflammation in tissues.

Prof Jonathan Grigg, whose group at Queen Mary University of London found evidence that air pollution particles are found in the placenta, said: “This study is biologically plausible, given that it has recently been discovered that inhaled fossil fuel particles move out of the lungs and lodge in organs throughout the body. Reproductive health can now be added to the growing list of harmful effects of fossil fuel particles, and should prompt policymakers to continue reducing traffic emissions.”

The link was evident despite excellent overall air quality during the study period, with PM10 and PM2.5 levels exceeding WHO guidelines on only 0.4% and 4.5% of study days, the scientists said. Australia is one of only seven countries to meet WHO guidelines in 2023, and this study is the latest to show evidence of harm even at relatively low levels of pollution.

According to Prof Geeta Nargund, senior NHS consultant and medical director of abc IVF and Create Fertility, further research is vital to better understand the full impact of air pollution, which disproportionately affects people from lower socio-economic backgrounds.

“Given the global fertility crisis, a clear picture of the link between environmental factors such as air pollution and fertility health or treatment outcomes could play an important role in addressing declining fertility rates,” she said.