SUBTLE PROGESTERONE RISE AFTER THE ADMINISTRATION OF THE GONADOTROPIN-RELEASING-HORMONE ANTAGONIST CETRORELIX IN INTRACYTOPLASMIC SPERM INJECTION CYCLES

In the present study, subtle serum progesterone rise (greater than or equal to 1.1 ng/ml) during the late follicular phase is reported, for the first time to our knowledge, in patients using a potent gonadotrop hin-releasing hormone (GnRH) antagonist, Cetrorelix, in combination wi th human menopausal gonadotrophin (HMG) for ovarian stimulation prior to intracytoplasmic sperm injection (ICSI), In five out of 24 patients (20%) serum progesterone levels were greater than or equal to 1.1 ng/ ml. The cycle characteristics of the patients were similar in both gro ups, No premature endogenous luteinizing hormone (LH) surge occurred a nd the serum LH concentrations were constantly low during the follicul ar phase, The 17-beta oestradiol and follicle stimulating hormone (FSH ) exposure were higher in cycles with premature luteinization, The gre ater oestradiol and FSH exposure confirm that one of the possible fact ors inducing subtle serum progesterone rise is the increased oestradio l and FSH-induced LH receptivity in granulosa cells.