However, the SAR of the immediate FET group was lower than that of the delayed FET group in the GnRH-ant protocol (adjusted for maternal age, BMI, trigger type, insemination method, embryo stage, number of embryos transferred, top or good quality embryo transfer, and cause of infertility) (adjusted OR, 0.645, 95% CI, 0.430–0.966) (P < 0.05). The gene discussed is GNRH1; the disease is Infertility.