GNRH1 and Infertility: The regression model included the following factors: maternal age (continuous variable), BMI (continuous variable), type of infertility (primary/secondary infertility), infertility diagnosis (tubal/male/others), COH protocols (GnRH-a protocol/GnRH-anti protocol), serum estradiol on the trigger day (<4000 pg/ml≥4000 pg/ml), EMT (≤7.5/7.6~12.0/>12.0 mm), number of gestational weeks (continuous variable) and sex of the newborn (male/female).