Reproductive outcome using a GnRH antagonist (cetrorelix) for luteolysis and follicular synchronization in poor responder IVF/ICSI patients treated with a flexible GnRH antagonist protocol.

To investigate the possible beneficial effect of a new stimulation protocol (termed ‘CRASH’) on the outcome of poor responder patients, a multicentre, prospective longitudinal study including a total of 36 women undergoing 72 IVF/intracytoplasmic sperm injection (ICSI) cycles with patients serving as their own controls, was conducted. A poor responder patient was defined as a patient with four or fewer oocytes extracted from five or fewer follicles and with a total FSH consumption exceeding 2000 IU in a preceding long agonist down-regulation protocol. The CRASH protocol included 3 mg of the gonadotrophin-releasing hormone (GnRH) antagonist cetrorelix given in the late luteal phase on cycle day 23. Stimulation with recombinant human FSH (rhFSH) started on cycle day 2, followed by a flexible GnRH antagonist protocol. The results showed significantly more follicles (5.4 versus 3.5), oocytes (4.3 versus 2.4) and transferable embryos (1.8 versus 0.8) with the CRASH protocol as compared with the preceding long protocol (P < 0.005 in all cases). The implantation rate and pregnancy rate per transfer was 18.4 and 38.5% respectively, approaching the clinical outcome of normal responder patients. The CRASH protocol thus may constitute an attractive alternative to conventional protocols for low responder patients, improving their clinical outcome.