Recombinant human FSH versus highly purified urinary FSH: a randomized study in intrauterine insemination with husbands' spermatozoa.

A randomized trial was carried out comparing recombinant FSH (rFSH) and highly purified urinary FSH (uFSH) in intrauterine insemination (IUI) with husbands' spermatozoa. A total of 45 women received rFSH (139 cycles), while 46 women received uFSH (155 cycles). The starting dose was 150 IU/day s.c., beginning on the second day, and on days 6-7 the dose was adjusted according to ovarian response, assessed by vaginal ultrasound and plasma oestradiol concentration. The pregnancy rate according to the intention to treat was 57.8% in rFSH versus 52.2% in uFSH, the corrected pregnancy rates 56.8% and 52.2%, and the cumulative pregnancy rates 69.6% and 61.0%, but the differences were not statistically significant. The per cycle pregnancy rate was 18.12% in rFSH and 15.48% in u-FSH, also not statistically significant. In the rFSH group, the consumption of FSH ampoules per cycle was significantly lower (19.20 +/- 7.02 versus 23. 80 +/- 10.78; P < 0.0001). The ratio of oestradiol/FSH ampoules was significantly higher in rFSH (56.45 +/- 31.26 versus 46.41 +/- 29. 25; P < 0.001). These data indicate that, in IUI cycles, rFSH has a higher potency than uFSH.