A multivariate logistic stepwise regression model was established, with variables including female age, basal serum LH and testosterone, AMH, infertility factors, proportion of PCOS, Gn starting dose, Gn total dose, E2 and LH levels on trigger day, the number of follicles ≥14 mm but <16 mm, the number of follicles ≥16 mm but <18 mm, retrieved oocytes, and MII oocytes. This evidence concerns the gene PLOD1 and polycystic ovary syndrome.