Impact of long-term exposure to greenness on poor ovarian response and ovarian sensitivity index in assisted reproductive technology patients

Background Environmental factors are increasingly recognized as potential determinants for poor ovarian response (POR) and ovarian sensitivity in fertility treatments. However, the impact of greenness on POR or ovarian sensitivity remains unclear. Methods We included 6509 patients undergoing their first infertility evaluation and treatment, where POR was defined in accordance with the Bologna Criteria. The ovarian sensitivity index (OSI) was computed as the total number of retrieved oocytes divided by the gonadotropin dose, multiplied by 1000. Residential greenness (normalized difference vegetation index, NDVI) exposure was assessed via satellite remote sensing. Multivariable regression models were used to estimate the associations of greenness exposure with both POR and OSI. Results Women in the highest quartile of greenness exposure 1 year (OR, 0.51, 95% CI, 0.40–0.67), 2 years (OR, 0.50, 95% CI, 0.38–0.65), and 3 years (OR, 0.50, 95% CI, 0.38–0.65) prior to oocyte retrieval had a lower risk of POR compared with those in the lowest quartile. Similarly, increased greenness exposure was significantly associated with increased OSI values. Additionally, the association between long-term greenness exposure and POR was more pronounced in women with a body mass index (BMI) < 24 kg/m² ( P interaction < 0.05), but no significant interaction was observed between BMI and greenness exposure with respect to OSI. Conclusion Higher long-term greenness exposure was associated with a reduced risk of POR and enhanced ovarian response sensitivity. This beneficial association was more pronounced in women with normal BMI. These findings highlight the protective value of green environments for the fertility of women of reproductive age.