A comparative prospective study of a chronic low dose versus a conventional ovulation stimulation regimen using recombinant human follicle stimulating hormone in anovulatory infertile women

The efficacy and safety of a chronic low dose (group A) and a conventional (group B) stimulation regimen of recombinant human follicle stimulating hormone (r-HFSH) were compared in 103 WHO Group II infertile women with clomiphene citrate-resistant anovulation. Mono- or bifollicular development was induced in 88.1% of patients in group A compared with 76.1% in group B. Ovulation and pregnancy rates were higher in group A (71.4% and 33.3%, respectively) than in group B (63.0% and 20%), but these differences were not statistically significant. Additionally, the total number of follicles that were >10 mm diameter was lower in group A than group B (3.0+/-2.6 versus 6.3+/-6.5; P < 0.0001), as was the oestradiol concentration (504+/-477 pg/ml versus 988+/-740 pg/ml; P < 0.03). The median dose of FSH (75 IU ampoules) used per cycle was 11 ampoules in group A and 12.5 in group B. In terms of the incidence of ovarian hyperstimulation syndrome, no differences were recorded between the two groups. The results demonstrated that r-HFSH is effective and safe in both these treatment protocols. The chronic low dose regimen was associated with a trend towards a higher rate of mono- or bifollicular development, without jeopardizing the incidence of pregnancy.