Effect of rescuing donated immature human oocytes derived after FSH/hCG stimulation following in vitro culture with or without Follicular Fluid Meiosis Activating Sterol (FF-MAS) - an embryo chromosomal and morphological analysis

Purpose: Studies in mice and humans have shown that Follicular Fluid - Meiosis Activating Sterol (FF-MAS) induces meiotic maturation of immature oocytes in vitro. A multicenter, prospectively randomised study evaluated chromosomal status of embryos from FSH/hCG primed human immature oocytes, cultured with or without FF-MAS. Methods: Denuded immature oocytes (n = 365) were randomly allocated into inert control, FF-MAS 5 mu M or 20 mu M. Seventy +/- 2 hours after ICSI on matured oocytes, all cleaved embryos were fixed for fluorescence in situ hybridisation analysis. Results: Only 15% of oocytes resulted in cleaved embryos. GV oocytes matured at significantly lower rates (14% and 7%) in the two FF-MAS groups compared to the inert control group (47%). High rates of chromosomal abnormalities were found in all groups. Conclusion: Immature oocytes showed poor development with high rates of embryo chromosomal abnormalities. Exposure to FF-MAS in the concentrations, duration and/or formulation used in this study did not improve the results.