A randomized study comparing IVF in the unstimulated cycle with IVF following clomiphene citrate

The efficiency of IVF in unstimulated cycles was compared with that followi ng ovarian stimulation with clomiphene citrate in a simple protocol with ul trasound monitoring only. A total of 132 couples with no previous IVF attem pts, selected by female age <35 years, indication for intracytoplasmic sper m injection or infertility caused by tubal factor or unexplained infertilit y were randomized to the two protocols. Randomization yielded two comparabl e groups. The clomiphene group (68 couples) performed significantly better than the unstimulated group (64 couples) in terms of number of cycles with oocyte harvest (90/111 or 81% versus 65/114 or 57%; <chi>(2) = 9.21, P < 0. 002), embryo transfers per started cycle (59/111 or 53% versus 29/114 or 25 %; <chi>(2) = 18.14, P < 0.0001), live intrauterine pregnancy rate per star ted cycle (20/111 or 18% versus 4/114 or 4%; <chi>(2) = 12.42, P < 0.0001), live intrauterine pregnancy rate per embryo transfer (20/59 or 34% versus 4/29 or 14%; <chi>(2) = 3.96, P = 0.047), but not in terms of implantation rate (22/85 or 26% versus 4/29 or 14%; chi (2) = 1.65). Only two twin pregn ancies occurred. Modest side-effects were recorded following clomiphene, Ac cordingly, a simple clomiphene citrate protocol, but not IVF in unstimulate d cycles, seems compatible with the concept of 'friendly IVF', yielding a f air pregnancy rate both per cycle started and per embryo transfer in select ed patients. The results do not substantiate any important negative anti-oe strogenic effects of clomiphene.