PRETREATMENT WITH FOLLICLE-STIMULATING-HORMONE PROMOTES THE NUMBERS OF HUMAN OOCYTES REACHING METAPHASE-II BY IN-VITRO MATURATION

The objective of this study was to investigate the effect of follicle stimulating hormone (FSH) priming on the in-vitro maturation (IVM) of human oocytes from healthy ovaries using a chemically defined culture system. Seventeen patients donating oocytes for research received a tr uncated course of 600 IU FSH over 5 days and a further control group o f nine patients received no FSH treatment. Midfollicular phase cumulus -enclosed oocytes (n = 160) were aspirated from follicles less than or equal to 4 mm diameter under transvaginal ultrasound guidance and wer e cultured for 48 h in microdrops of medium containing 10 mIU/ml FSH a nd 100 mIU/ml human chorionic gonadotrophin (HCG). The results demonst rated that human oocytes will efficiently undergo IVM under serum-free conditions. After mild FSH stimulation, a greater number of cumulus-e nclosed oocytes was collected, and following culture, a lower rate of degeneration was observed, Significantly more oocytes completed nuclea r maturation to metaphase II following FSH stimulation (71.1 versus 43 .5%), In conclusion, a truncated course of FSH stimulation in vivo imp roved the oocyte maturation rate in vitro, giving a mean of 4.8 +/- 0. 7 metaphase II oocytes per patient compared with only 2.1 +/- 0.7 from control patients, thus yielding more mature oocytes for future IVF tr eatment.