Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital

Multiple follicular wave theory proposed by Baerwald et al. implied that follicle recruitment may occur in the luteal phase of menstrual cycle. Therefore, luteal phase ovarian stimulation (LPOS) was considered as a potential feasible stimulation method during in vitro fertilization (IVF) cycle. In the beginning, in order to avoid delaying cancer treatment, LPOS was applied for fertility preservation of cancer patients, showing no difference in numbers of oocyte retrieved, mature oocytes and fertilization rate between luteal or follicular phase stimulation. In the recent, LPOS was used for infertility women, suggesting that LPOS owned quite good IVF outcomes. In previous studies, premature luteinizing hormone (LH) surge, a major reason worsening ovarian quality in poor ovarian responders (PORs), was seldom found in LPOS. High progesterone in luteal phase may aid in suppressing premature LH surge. An updated research claimed that numbers of oocyte retrieved, mature oocytes and fertilized oocytes in LPOS significantly increased when compared to follicular ovarian stimulation. Therefore, the investigators presumed that LPOS was a more effective method than follicular stimulation in PORs.