BIOCLIMATOLOGICAL DRUGS FOR REPRODUCTIVE DISORDERS - A REVIEW OF DEVELOPMENTS

Recombinant gonadotrophins, in particular recombinant follitropin (fol licle-stimulating hormone: FSH), are now available for ovarian hyperst imulation for assisted reproduction. In contrast with urinary FSH (uro follitropin), follitropin is available in virtually unlimited quantiti es. Follitropin is as potent as urofollitropin in all protocols of ova rian stimulation. Furthermore, it shows an improved purity without con tamination by urinary proteins not related to FSH, and can be injected subcutaneously by the patients themselves. In patients with complete luteinising hormone (LH) deficiency, follitropin stimulates follicular development, although serum levels of estradiol remain low. For this group of patients the addition of LH is necessary. Ongoing phase III s tudies on the use of recombinant LH in this indication will provide an answer to how much LH is needed in order to guarantee sufficient foll icular growth and hormonal response. Gonadorelin (gonadotrophin releas ing hormone; GnRH) analogues are used to avoid the surge of endogenous LH in ovarian stimulation protocols. Gonadorelin antagonists are now in clinical testing for the same indication. Gonadorelin antagonists a llow sufficient suppression of endogenous LH levels. In contrast with gonadorelin analogues, they avoid any flare-up effect, i.e. an initial release of gonadotrophins from pituitary reservoirs. Recombinant gona dotrophins and gonadorelin antagonists are new tools towards a more in dividual approach to ovarian stimulation.