Robust and simple in vitro maturation of ovarian tissue oocytes

Using in-vitro gametogenesis studies, to accomplish robust in-vitro maturation (IVM) of oocytes from human ovarian tissue. A total of 144 females underwent ovary tissue cryopreservation since 1977. The most recent 36 consecutive such patients between 2 and 38 years of age underwent in-vitro maturation of oocytes (IVM) derived from their ovarian tissue. After ovarian cortex dissection, the spent media was examined for cumulous complexes (CC’s), which were placed in culture with widely varying concentrations of FSH and HCG, and in a variety of different media based on now established mechanisms of in vitro oogenesis. The cumulous was stripped between 24 and 44 hours. Any oocytes that had advanced from GV to M II were vitrified. There was no prior hormone administration. The harvested germinal vesicle oocytes developed into mature metaphase II oocytes with simple culture media just as well as with “IVM media”, and with HCG concentration from 10 mIU/l to 1000 mIU/l. Of the 36 cases, 16 had had previous chemotherapy or were pre-pubertal. None of these had CC’s. Of the 20 who were post-pubertal and had not yet undergone chemotherapy, the number of CC’s averaged 20 per patient. Of a total of 402 GV oocytes, 137 became mature MII’s (34.1%), varying between 20% and 56%. The only case with low maturation rate (9%) occurred when the cumulus was stripped immediately instead of at 24 hours. Many mature oocytes can robustly and easily be obtained from ovary tissue with simple media and no need for ovarian stimulation. Ovarian stimulation and ovulation are not necessary for oocyte maturation.