Exposure to air pollution before egg retrieval may lower pregnancy success rates through in vitro fertilization, a study finds.
- Exposure to PM10 fine particles in the two weeks before egg collection reduced the chances of a live birth through in vitro fertilization by 38%, according to a study.
- Exposure to PM2.5 in the three months prior to collection was also associated with “reduced odds of live birth.”
- “Our results suggest that pollution negatively affects egg quality, not just the early stages of pregnancy, which is a distinction that has not been reported before,” the researchers said.
“Climate change and air pollution remain the greatest threats to human health, and human reproduction is not immune to this.”says Dr. Sebastian Leathersich, a gynecologist and fertility specialist, citing numerous studies showing the negative effects of pollution on births.
He and his team of researchers have recently demonstrated that exposure to fine particles is likely to drastically reduce the chances of a successful pregnancy through in vitro fertilization. Their work was presented at the annual congress of the European Society of Human Reproduction and Embryology (ESHRE) in Amsterdam, the Netherlands.
Exposure to air pollution reduces chances of live birth
To reach this conclusion, the scientists analyzed, over an eight-year period, nearly 3,700 frozen embryo transfers from some 1,800 patients, whose median age was 34.5 years at the time of oocyte retrieval and 36.1 years at the time of embryo transfer. In parallel, they examined the concentrations of air pollutants in the patients’ environment over four exposure periods preceding oocyte retrieval (24 hours, 2 weeks, 4 weeks and 3 months).
As a result, it appeared that “Exposure to PM10 fine particles during the two weeks preceding egg collection reduced the chances of a live birth by 38%” comparing the highest exposure quartile to the lowest quartile, according to a communicated. On the other hand, exposure to PM2.5 during the three months preceding their collection was associated with “a reduction in the chances of live birth, from 0.90 in the second quartile to 0.66 in the fourth quartile.”
Of note, the negative impact of air pollution was observed despite excellent overall air quality during the study period, with PM10 and PM2.5 levels exceeding WHO guidelines by only 0.4% and 4.5% respectively.
Air pollution negatively affects egg quality
“This is the first study that used frozen embryo transfer cycles to separately analyze the effects of exposure to pollutants during egg development and at the time of embryo transfer and early pregnancy, explains Dr. Leathersich. Our results suggest that pollution negatively affects egg quality, not just early stages of pregnancy, which is a distinction that has not been previously reported. […] Reducing exposure to pollutants must be a key public health priority.”