REDUCED IN-VITRO FERTILIZATION OF HUMAN OOCYTES CORRELATES WITH RAISED CIRCULATING FSH-LEVELS DURING OVARIAN STIMULATION IN NORMOGONADOTROPIC WOMEN DOWN-REGULATED WITH GNRH-ANALOGS

Purpose: The possible effects of circulating FSH levels as used during IVF treatment on oocyte maturation and subsequent preembryo developme nt were evaluated. Methods: Serum levels of FSH and LH on days 1 and 8 of ovarian stimulation and on the day of oocyte retrieval (OR) were c orrelated with subsequent preembryo development in vitro. After pituit ary downregulation, 244 normogonado-tropic women followed a Fred proto col for the first 7 days of stimulation. Results: The average FSH conc entration on day 8 of stimulation was 11.5 IU/L and exceeded the expec ted midcycle surge of FSH by more than 25%. In contrast, levels of LH were below an average of 2 IU/L throughout the stimulation period. The concentration of FSH on day 8 and oil the day of OR Showed a signific ant inverse correlation with cleavage rate, whereas levels of LH, age, and body mass index showed no such correlation. Conclusions: Supraphy siologic levels of FSH seems to affect oocyte maturation negatively. P remature resumption of meiosis, leading to retrieval of postmature ooc ytes with a reduced developmental potential, is suggested as the under lying mechanism.