RESUMEN
This pilot study evaluated the possibility of preventing early ovarian hyperstimulation syndrome (OHSS) by increasing the daily dose of gonadotrophin-releasing hormone (GnRH) antagonist administration (to twice a day) in oocyte-donor cycles stimulated with the antagonist protocol. The study included 72 oocyte donors who underwent ovarian stimulation using the GnRH antagonist protocol and might have had their cycle cancelled because of ovarian hyper-response. All women were donors presenting a rapid rise of oestradiol > or = 3000 pg/ml early in the stimulation period with more than 15 follicles of < or = 15 mm in diameter. By decreasing the rFSH dose to 75 IU a day with an additional daily dose of GnRH antagonist (0.25 mg twice a day), the oestradiol concentrations were lowered or reached a plateau before human chorionic gonadotrophin was given. A marked decrease in oestradiol concentrations and ovarian volume was observed on the day of oocyte retrieval and 3 days post retrieval. None of the donors needed coasting, were cancelled or developed OHSS. In over-responding oocyte donors, by increasing the usual GnRH-antagonist dose to twice a day during ovarian stimulation, the oestradiol rise can be blocked while a minimal follicular stimulation may continue without the risk of developing OHSS or affecting the outcome.