Basal serum levels of FSH and estradiol in ovulatory and anovulatory women undergoing treatment by in-vitro maturation of immature oocytes.

BACKGROUND: The study aim was to establish whether basal serum levels of FSH and estradiol are predictive of outcome in women undergoing treatment by in-vitro maturation (IVM) of immature oocytes.
METHODS: Data were obtained from 123 unstimulated IVM cycles. Serum was taken between cycle days 2-4 for analysis. Patients received 10 000 IU of HCG 36 h before immature oocyte recovery that was performed between cycle days 9-14. IVM was performed and mature oocytes fertilized by ICSI, followed 2-3 days later by embryo transfer. Outcome measures included the number of immature oocytes retrieved, and the rates of oocyte maturation, fertilization, cleavage and pregnancy.
RESULTS: A median (range) of 8 (0-36) immature oocytes was retrieved per patient. Oocyte maturation, fertilization, cleavage and pregnancy rates were 83, 76, 93 and 17.9% respectively. Serum FSH levels and the presence of polycystic ovary were significant independent predictors of the number of immature oocytes retrieved, whilst patient age and basal estradiol level were not. A basal serum estradiol level >100 pmol/l was associated with a significantly higher pregnancy rate (26 versus 11% for estradiol <100 pmol/l; P = 0.032).
CONCLUSIONS: Measurement of basal serum levels of FSH and estradiol are useful in predicting the number of immature oocytes retrieved and the pregnancy rate in women undergoing unstimulated IVM treatment.