Oestradiol Valerate Pretreatment in GnRH-antagonist Cycles: a Randomized Controlled Trial

This randomized controlled trial analyses the ability to control the oocyte retrieval schedule of gonadotrophin-releasing hormone antagonist cycles through the administration of oestradiol valerate during the luteo-follicular transition period prior to the initiation of ovarian stimulation. Eighty-six women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection were enrolled in the study. The control group (n = 42) received a standard ovarian stimulation protocol. In the pretreatment group (n = 44), patients were administered oestradiol valerate at a daily dose of 2 · 2 mg from day 25 of the preceding cycle onwards, during 6–10 consecutive days, depending on the day of the week. The primary endpoint was the proportion of patients undergoing oocyte retrieval during a weekend day (i.e. Saturday or Sunday), which was significantly lower in the pretreatment group (1/37, 2.7%) compared with the control group (8/39, 20.5%; P value = 0.029). The clinical pregnancy rates per started cycle were similar in the pretreatment group (38.6%) compared with the control group (38.1%). Pretreatment with oestradiol valerate results in a significantly lower proportion of patients undergoing oocyte retrieval during a weekend day and can be a valuable tool for the organization of an assisted reproduction centre.