Peter Kemeter *, Monika Stroh-Weigert, Wilfried Feichtinger; Wunschbaby Institut Feichtinger, Vienna, Austria The 18th World Congress on Controversies in Obstetrics, Gynecology & Infertility (COGI), Vienna, Austria, October 24-27, 2013, Vienna, Austria; 10/2013
- Introduction: Differences in the mode of action between recombinant FSH (rFSH) preparations and urinary derived FSH (uFSH) or hMG preparations have been reported in cycles down-regulated by GnRH-agonists. The aim of our study was to determine, if these differences also exist in cycles down-regulated by GnRH-antagonists. Methods: GnRH-antagonist cycles performed between 2009 – 2012 were divided into two groups: 1. 203 cycles stimulated with Follitropin alfa plus 443 cycles stimulated with Follitropin beta (rFSH), and 2. 405 cycles stimulated with Urofollitropin (uFSH). Cetrorelix or Ganirelix were used as GnRH-antagonists. All patients received 75 IU hMG additionally from day 6 of stimulation onwards up to the day of hCG administration. Initially, a logistic regression analysis was conducted to find the most significant parameters predicting hCG-positive pregnancy for 2471 IVF cycles. The results demonstrated that the predictors age of patients (p<0,001) and number of cycles ever performed (p=0,003) made negative contributions and number of oocytes retrieved (p=0,076) and number of embryos transferred (p<0,001) made positive contributions to prediction. Taking this into consideration, comparable groups could be created by including only first-ever IVF cycles with more than 10 oocytes retrieved and 2 embryos transferred. Thus, the final sample for comparison included 98 patients in the rFSH-group and 27 patients in the uFSH group. Results: There were no differences in basic personal data and gonadotropin consumption between the groups. Stimulation with rFSH resulted in a higher yield of oocytes compared to uFSH (15,6 vs. 14,4 m.n.), however, the results of the following reproductive outcome parameters were all in favour of uFSH when rFSH and uFSH were compared: oocyte maturation rate (76.5% vs. 79.0 %), fertilization rate (53,6% vs. 58,6%), embryo score 4 rate (25,7% vs. 31,1%), hCG-positive pregnancy rate (43,9% vs. 59,3%), clinical pregnancy rate (33,7% vs. 44,4%), embryo-cryopreservation rate (19,3% vs. 30,5%) and abortion rate (14,0% vs. 12,5%). Conclusion: These results seem to support the concept that uFSH produces fewer oocytes than rFSH, but the oocytes produced by uFSH are, on an average, of better quality than those produced by rFSH. Basic studies have shown that different FSH isoforms with different elimination kinetics in the two gonadotropin preparations could be responsible for this different effects. Our preliminary results, based on a retrospective study, have to be confirmed, however, by well designed prospective randomized studies. * corresponding author. E-mail address: peter.kemeter@wunschbaby.at