GNRH1 and polycystic ovary syndrome: Besides, the benefits of the GnRH-a ultra-long protocol for endometriosis have been widely discussed [40–42], and a few studies have also shown its superiority in the general IVF/ICSI population [43], in patients who had a history of progestin-primed ovarian stimulation failure [44], in poor ovarian responders [45] and in women with polycystic ovary syndrome [46].