Impact of residential air pollution on in vitro fertilization (IVF) outcomes in New Jersey.

PURPOSE: The purpose of this study is to identify the impact of air quality (AQ) measured by air quality index (AQI) on IVF outcomes.

METHODS

Retrospective cohort study including 5614 IVF cycles with preimplantation genetic testing for aneuploidy (PGT-A) and 5,618 single euploid frozen embryo transfer (FET) cycles at a single academic center in New Jersey from January 2020 to December 2023. Fifteen counties were categorized into tertiles and quintiles based on the number of days with AQI > 50. IVF outcomes (fertilization, blastulation, euploidy) and FET outcomes (sustained implantation rate (SIR), pregnancy loss, ectopic pregnancy) were compared across AQI groups. A subgroup analysis was conducted for May-July 2023 during AQ deterioration from Canadian wildfires, comparing outcomes by daily EPA AQI levels.

RESULTS

IVF outcomes (fertilization, blastulation, arrest, euploidy) did not differ by AQI group, even after adjusting for confounders (age, BMI, AMH, day 3 FSH). In FET cycles, no difference in SIR was seen between the best and worst AQ tertiles (OR, 0.943; CI, 0.822-1.081; p = 0.396). A significant decrease in SIR was observed between the best and middle tertile (OR, 0.838; CI, 0.728-0.966; p = 0.015), but not in other comparisons. No differences were seen in pregnancy loss or ectopic rates. During wildfire-related AQ deterioration, no differences were found in embryology or clinical outcomes by daily AQI.

CONCLUSION

IVF and euploid FET outcomes were not affected by AQI levels within the observed range, including during transient declines in air quality. These findings suggest that ambient AQ deviations in the range measured in this study are unlikely to compromise IVF success, though further studies are needed to assess dose-response and individual susceptibility.