Ovarian stimulation using pure FSH in an in-vitro fertilization programme.

The therapeutic efficacy of stimulating ovarian follicular development by pure urinary FSH in an IVF programme was determined and compared with results of other therapeutic regimens. Forty-three patients selected for extracorporeal fertilization were treated with pure FSH after stimulation with clomiphene or HMG had proved to be unsuccessful. Treatment had to be discontinued in five patients before follicular puncture, and embryo transfer was performed in 32, of whom seven conceived. FSH stimulation evidently creates favourable conditions for in-vitro fertilization in patients with impaired follicular maturation following conventional stimulation with clomiphene or HMG. Levels of oestradiol, progesterone and androstenedione were measured in follicular fluid, and high progesterone concentrations were correlated with mature oocytes. The increased ratios of progesterone/androstenedione and progesterone/oestradiol in follicles containing mature oocytes are due to the onset of luteinization of mature follicles as a consequence of HCG administration.