Air pollution linked to drop in live births among IVF patients

Exposure to fine particulate matter (PM) prior to the retrieval of oocytes during IVF can reduce the odds of achieving a live birth by almost 40 per cent, new research has shown. 

The study, presented at the ESHRE 40^th annual meeting in Amsterdam, analysed PM₁₀ exposure in the two weeks leading up to oocyte collection and found that the odds of a live birth decreased by 38 per cent when comparing the highest quartile of exposure to the lowest quartile.

Conducted over an eight-year period in Perth, Australia, the research analysed 3,659 frozen embryo transfers from 1,836 patients.

The study examined air pollutant concentrations over four exposure periods prior to oocyte retrieval – 24 hours, two weeks, four weeks, and three months – with models created to account for co-exposures.

Increasing PM_2.5 exposure in the three months prior to oocyte retrieval was also associated with decreased odds of live birth, falling from 0.90 in the second quartile to 0.66 in the fourth quartile.

Importantly, the negative impact of air pollution was observed despite excellent overall air quality during the study period, with PM₁₀ and PM_2.5 levels exceeding WHO guidelines on just 0.4 per cent and 4.5 per cent of the study days, respectively.

“This is the first study that has used frozen embryo transfer cycles to separately analyse the effects of pollutant exposure during the development of eggs and around the time of embryo transfer and early pregnancy,” explained Dr Sebastian Leathersich, lead author of the study.

“We could therefore evaluate whether pollution was having an effect on the eggs themselves, or on the early stages of pregnancy.

“Even in a part of the world with exceptional air quality, there is a strong negative correlation between the amount of air pollution and the live birth rate in frozen embryo transfer cycles. Minimising pollutant exposure must be a key public health priority,” he added.

Professor Dr Anis Feki, chair-elect of ESHRE, said: “This important study highlights a significant link between air pollution and lower IVF success rates, with a notable reduction in live births associated with higher particulate matter exposure before oocyte retrieval.

“These findings emphasise the need for ongoing attention to environmental factors in reproductive health.”