Prolonged Protocol of Early Follicular or Mid Luteal Phase

Due to the injection of gonadotropin releasing hormone agonist (GnRH-a) before controlled ovarian hyperstimulation (COH), the scheme of prolonged early follicular period protocol has obvious advantages in achieving ideal egg number, increasing endometrial receptivity to embryo transfer, inhibiting endogenous luteinizing hormone (LH) peak and reducing cycle cancellation rate. The full dose of long acting GnRH-a was also applied before COH in the mid luteal Hypergrowth program, and the mechanism of its lowering tone was similar. But whether the clinical and perinatal outcome of early follicular hyperlengthening is as effective as that of mid luteal hyperlengthening has not been reported at home and abroad. Moreover, there is a lack of prospective randomized controlled studies.