PIONEERING research presented at the European Society of Human Reproduction and Embryology (ESHRE) 40th Annual Meeting in Amsterdam, The Netherlands, suggests that exposure to fine particulate matter (PM) before the retrieval of oocytes during in vitro fertilisation (IVF) can significantly reduce the odds of achieving a live birth by almost 40%. The study was conducted over eight years in Perth, Australia, and included 3,659 frozen embryo transfers from 1,836 patients.
The research team, led by Sebastian Leathersich, Fertility Specialists of Western Australia, Perth, Australia, analysed the exposure to PM10 for two weeks before oocyte collection. They compared the highest quartile of exposure (18.63 to 35.42 µg/m3) to the lowest quartile (7.08 to 12.92 µg/m3). The study also examined PM2.5 exposure over various periods (24 hours, 2 weeks, 4 weeks, and 3 months) before oocyte retrieval, creating models to account for co-exposures.
The study found that the odds of a live birth decreased by 38% when comparing the highest to the lowest quartile of PM10 exposure (odds ratio [OR] 0.62, 95% confidence interval [CI] 0.43-0.89, p=0.010) when comparing the highest quartile of exposure to the lowest. Increased PM2.5 exposure in the three months before oocyte retrieval was also associated with decreased odds of live birth, reducing from 0.9 (95% CI 0.70-1.15) in the second quartile to 0.66 (95% CI 0.47-0.92) in the fourth quartile. Importantly, these negative impacts were observed despite overall excellent air quality during the study period.
Leathersich concluded that pollution negatively affects the quality of oocytes, not just the early stages of pregnancy. He further stressed that even in areas with exceptional air quality, there is a strong negative correlation between air pollution and the live birth rate in frozen embryo transfer cycles. Overall, these findings suggest minimising pollutant exposure should be a key public health priority to improve reproductive outcomes.
Abigail Craig, EMJ
