Poor air quality from Canadian wildfires did not impact IVF outcomes at New Jersey clinic
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Key takeaways:
- Poor air quality from Canadian wildfires did not impact fertility outcomes for patients in New Jersey undergoing oocyte retrieval or frozen embryo transfer.
- More data are needed on longer exposure to poor air quality.
DENVER — Poor air quality during the Canadian wildfires in 2023 did not affect embryology outcomes for patients at a fertility clinic in New Jersey who underwent oocyte retrieval or frozen embryo transfer, researchers reported.
“During June 2023, the air quality in New Jersey was very poor due to the Canadian wildfires,” Blake Vessa, MD, a reproductive endocrinology and infertility fellow with Reproductive Medicine Associates in Basking Ridge, New Jersey, told Healio at the ASRM Scientific Congress & Expo. “We were curious if, during that short-term insult of air quality, there was any impact on embryology and pregnancy outcomes for both our patients undergoing embryo cryopreservation and those undergoing frozen embryo transfer with previously cryopreserved embryos.”
Researchers analyzed data from all patients undergoing a vaginal oocyte retrieval for embryo cryopreservation from May through July 2023 — periods before and after air quality changed in New Jersey — as well as all patients undergoing frozen embryo transfer in June 2023 with previously cryopreserved embryos from prior to the change in air quality.
Researchers compared outcomes among four air quality index (AQI) groups, based on EPA criteria of good (mean AQI, 39.7), moderate (mean AQI, 64.8), unhealthy for sensitive groups (mean AQI, 119) and unhealthy for all groups (mean AQI, 169.9) on the corresponding days of oocyte retrieval or frozen embryo transfer. For the oocyte retrieval group (n = 836), primary outcome was blastulation rate per fertilized zygote; secondary outcomes included embryology parameters. For frozen embryo transfer group (n = 302), primary outcome was sustained implantation rate, defined as fetal heartbeat at 8 to 9 weeks; secondary outcomes included pregnancy loss rates.
The data showed air quality in New Jersey in June was worse than in May and July, with a mean AQI of 69.3 vs. 46.5 and 58.8, respectively (P < .001).
Researchers saw no differences in embryology outcomes or sustained implantation rate (P = 0.45), clinical loss (P = 0.6) or ectopic pregnancy rates (P = 0.19) between groups.
“The brief and acute change in air quality for that period did not appear to affect the outcomes in our clinic, but it would be interesting to see if the patients who were freezing embryos during that time had worse pregnancy rates,” Vessa told Healio. “These data are reassuring to our patients who cycled during this time, when the air quality was very poor, that they will not have worse outcomes due to that short-term exposure.”
Vessa also said that it remains unclear if longer-term exposure to poor air quality could negatively impact fertility or pregnancy outcomes.