a preliminary report of a low-dose step-up regimen of recombinant human fsh for young women undergoing ovulation induction with iui

background: the aim of this study was to evaluate the efficacy and safety of a recombinant human follicle stimulating hormone (r-fsh) low-dose step-up regimen for controlled ovarian hyperstimulation in patients undergoing ovulation induction (oi) with intrauterine insemination (iui). materials and methods: the study was conducted in the department of obstetrics and gynecology, far eastern memorial hospital, new taipei, taiwan. in this prospective, observational study, consecutive infertile women (20-35 years) with regular menstrual cycles and a normal baseline fsh level were prospectively enrolled between january 2010 and september 2010. a starting dose of 112.5 iu/day r-fsh was administered on day 3 and increased by 37.5 iu/day every 2 days until a follicle ≥11 mm in diameter was present. recombinant human chorionic gonadotropin (r-hcg) was administered when a follicle ≥18 mm was noted. monifollicular development was defined as only one follicle with a diameter ≥16 mm. clinical pregnancy was defined as a pregnancy diagnosed by ultrasonographic visualization of one or more gestational sacs. results: a total of 29 women and 30 cycles were included. the mean daily dose of r-fsh to achieve a follicle of ≥11 mm in diameter was 131.3 ± 23.6 iu and the mean total dose was 1030.0 ± 383.2 iu. approximately 41% of the cycles were monofollicular. clinical pregnancy was observed in 9 (30.0%) cycles, and a fetal heart beat was observed in 7 (23.3%). there were no multiple pregnancies. mild ovarian hyperstimulation syndrome, which was resolved with conservative management, was observed in 3 (10.0%) cycles. conclusion: this r-fsh low-dose step-up regimen seems to be a feasible and practical method for oi in younger infertile women undergoing iui.