The influence of ambient air pollution during folliculogenesis, endometrial development, and spermatogenesis on fertility: A study among patients using vitrified donor oocyte in vitro fertilization.

BACKGROUND

Air pollution is associated with reduced fertility; however, the independent effects of air pollution exposure during folliculogenesis, endometrial development, and spermatogenesis on human reproduction remains unclear.

OBJECTIVE

We investigated the associations between air pollution during critical windows and clinical outcomes of in vitro fertilization (IVF) using patients undergoing vitrified donor oocyte IVF.

METHODS

We included 551 non-identified oocyte donors and 1353 recipients who underwent 2533 embryo transfers at Reproductive Biology Associates in Atlanta, Georgia (2008-2019). Daily ambient exposure to air pollutants was estimated using spatiotemporal models linked to residential addresses and averaged over folliculogenesis (90 days before stimulation) and during stimulation in donors, three months and three weeks prior to transfer in recipients, and spermatogenesis (72 days prior to oocyte thaw) in male partners. Multivariable generalized estimating equations were used to estimate adjusted odds ratios (aOR) and 95 % confidence intervals (CI) per interquartile range increase in pollutants in relation to clinical IVF outcomes.

RESULTS

Higher carbon monoxide (CO) exposure during folliculogenesis (aOR = 0.86 95 % CI 0.77, 0.96) and ovarian stimulation (aOR = 0.88 95 % CI 0.79, 0.98) in donors was associated with lower odds of positive pregnancy test. Higher elemental carbon (EC) exposure during folliculogenesis was associated with lower odds of live birth (aOR = 0.87 95 % CI 0.79, 0.96) and higher odds of pregnancy loss (aOR = 1.16 95 % CI 1.02, 1.32). During ovarian stimulation, higher coarse particulate matter (PM10) exposure was associated with lower odds of live birth (aOR = 0.90 95 % CI 0.80, 1.00) and higher odds of pregnancy loss (aOR = 1.18 95 % CI 1.02, 1.36). Among male partners, higher PM10 exposure during spermatogenesis was associated with higher odds of pregnancy loss (aOR = 1.45 95 % 1.09, 1.92). Air pollution exposures in the recipient were generally not associated with IVF outcomes.

CONCLUSIONS

Preconception air pollution exposure during both folliculogenesis and spermatogenesis may adversely impact IVF outcomes.