Although there is not consensus that intrauterine insemination (IUI) with partner’s sperm combining with ovarian stimulation seems to provide higher pregnancy rate than insemination in a natural menstrual cycle without ovarian stimulation.
Insemination combined with ovarian stimulation with injectable gonadotropins (pergonal or follistim) provides better pregnancy rate and higher multiple pregnancy chance as compared to insemination combined with oral clomiphene citrate (clomid).
Injectable gonadotropins usually stimulate more mature eggs to develop than does clomiphene citrate. More mature follicles and eggs leads to higher pregnancy rate. However, more follicles and eggs may also induce higher chance of multiple pregnancies.