DOSE-RESPONSE-RELATIONS AFTER APPLICATION OF FSH - FOLLICULAR-GROWTH AND RESULTS OF SUPEROVULATION

Dose-response-relations were investigated after application of FSH in superovulatory treatments. Results were recovered from basic experimen ts and from a clinical study. Starting with low FSH doses, the number of ovulations increased when FSH dose was increased. The number of ovu lations reached a plateau and then decreased when FSH doses were furth er increased above an optimum. High doses of FSH can suppress ovulatio ns completely. We conclude from our results that at least two mechanis ms are responsible for suppression of ovulations. The first mechanisme n consists of high FSH doses increasing progesterone concentrations pr ior to ovulation. Under these circumstancis estradiol is not able to i nduce LH peak. As a consequence ovulations are suppressed completely. Moreover, follicles do not, or in a limited number, respond to LH peak . We speculated that dysregulation in the cells of the follicular wall is the reason for this. It is possible to conclude that FSH doses abo ve an optimum are not able to increase number of transferable embryos above the actual limit of 6 to 8 embryos per donor.