GnRH antagonists and mild ovarian stimulation for intrauterine insemination: a randomized study comparing different gonadotrophin dosages

BACKGROUND: The precise role of GnRH antagonists in the armamentarium of drugs for stimulation of ovulation associated with intrauterine insemination remains to be clarified. In this study, we have compared two different protocols employing GnRH antagonists in order to determine the lower effective dose of gonadotrophins to use. METHODS: Sixty-six couples with unexplained infertility or moderate male subfertility were recruited. Starting on day 3 of the cycle, 32 patients were randomized to receive 50 IU of recombinant FSH per day, whereas 34 were treated with 50 IU of recombinant FSH on alternate days. Women received the GnRH antagonist Ganirelix at a dose of 0.25 mg per day starting on the day in which a leading follicle > or =14 mm in mean diameter was visualized, until HCG administration. Insemination was performed 34 h after HCG injection. RESULTS: The regimen with daily recombinant FSH was associated with a lower rate of mono-ovulation (53.3% versus 78.8%, P=0.06) but also with a higher clinical pregnancy rate per initiated cycle (34.4% versus 5.9%, P=0.005). CONCLUSIONS: A protocol of recombinant FSH 50 IU daily and GnRH antagonist may represent an effective and safe regimen for ovulation induction associated with intrauterine insemination.