And the secondary outcomes in this study include the Gn dosage, duration of COH, endometrial thickness and pattern, LH, E2, P level on trigger day, numbers of retrieved oocytes, high-quality embryo rate, biochemical pregnancy rate, clinical pregnancy rate, implantation rate, ectopic pregnancy rate, early miscarriage rate, multiple pregnancy rate and incidence of moderate and severe OHSS. The gene discussed is PLOD1; the disease is ovarian hyperstimulation syndrome.