Key points:
- Ambient (outdoor) pollution including fine particulate matter is associated with poor health and reproductive outcomes.
- Fine particulate matter exposure prior to the retrieval of oocytes during IVF reduces the odds of live birth by almost 40%.
- These findings highlight the importance of considering environmental factors and pollution in reproductive health.
Ambient (outdoor) air pollution is a major environmental risk to human health. Exposure to fine particulate matter (PM) is linked to adverse health conditions, including cardiovascular and respiratory disease. Epidemiological data show a clear correlation between pollution and poorer reproductive outcomes, but the mechanisms are not well understood.
Now, a new study, presented at the ESHRE 40th Annual Meeting in Amsterdam, shows that exposure to fine PM prior to oocyte retrieval during in vitro fertilization (IVF) reduces the odds of a live birth.
Over an eight-year period in Perth, Australia, researchers analyzed 3,659 frozen embryos from 1,836 patients to determine the pollutant concentrations over four exposures prior to oocyte retrieval – 24 hours, 2 weeks, 4 weeks, and 4 months. By analyzing PM10 exposure in the two weeks leading up to oocyte collection, they found that the odds of a live birth decreased by 38% when comparing the highest quartile of exposure to the lowest quartile.
In the 3 months prior to oocyte retrieval, the team found that increasing PM2.3 exposure was also associated with decreased odds of live birth. Their models revealed that the negative impact of pollution was present despite excellent overall air quality during the study period.
“This is the first study that has used frozen embryo transfer cycles to separately analyze the effects of pollutant exposure during the development of eggs and around the time of embryo transfer and early pregnancy,” explained lead study author Sebastian Leathersich. “We could therefore evaluate whether pollution was having an effect on the eggs themselves, or on the early stages of pregnancy.”
Climate change and pollution threaten human health and reproduction. The team hopes their findings will bring the risks associated with pollutant exposure to the forefront of public health research.
“This important study highlights a significant link between air pollution and lower IVF success rates,” said Anis Feki, Chair-Elect of ESHRE. “These findings emphasize the need for ongoing attention to environmental factors in reproductive health.”