Poor ovarian response is associated with air pollutants: A multicentre study in China

Background Human evidence on the association between air pollution and ovarian response is scarce. Poor ovarian response (POR) with an incidence of 5-35% is a tricky problem in IVF treatment. Methods In this large-scale multicentre study, we included 2186 women with POR (< 4 oocytes retrieved) and 7033 women with a normal ovarian response (10-15 oocytes retrieved), who underwent their first in vitro fertilization treatment in five cities in northern China during 2015-2020. Average concentrations of six air pollutants (PM2.5, PM10, O-3, NO2, CO, and SO2) during different exposure windows (5 days, 1, 3, 6, and 12 months) before oocyte pick up (OPU) were calculated using data from the air monitoring station nearest to the residential site as approximate individual exposure. Logistic regression models were employed to assess the association between exposure to air pollutants and the risk of POR. Stratification analyses were conducted based on female age. Sensitivity analyses were performed in poor responders identified by Bologna criteria and women with unexpected POR. Findings We detected that increased SO2 exposure during all exposure windows before OPU was associated with a higher risk of POR, especially for women <= 30 years old. In the stratified analysis, the effect sizes were larger for the unexpected poor ovarian response. Interpretation The findings provide human evidence for adverse effects of exposure to ambient air pollutants on ovarian response and underscore the need to reduce ambient air pollution exposure in women of reproductive age to protect human fertility. Copyright (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Automated summary

This large-scale study found that exposure to ambient air pollutants was associated with an increased risk of poor ovarian response, especially for women under 30 years old. The findings underscore the importance of reducing ambient air pollution exposure in women of reproductive age to protect human fertility.