Serum IGF‐1 concentrations following pituitary desensitization do not predict the ovarian response to gonadotrophin stimulation prior to IVF

BACKGROUND: Insulin-like growth factor-1 (IGF-1) is known to play a role in ovarian follicular development augmenting the action of FSH. Low intrafollicular concentrations have been detected in women who respond poorly togonadotrophins. This study addresses the relationship between serum IGF-1 levels following pituitary desensitization and ovarian response to gonadotrophin stimulation. METHODS: This is a case-control study of 78 patients undergoing IVF-embryo transfer treatment. Thirty-nine strictly-defined poor responder patients requiring 50 or more ampoules (75 IU FSH) to reach oocyte retrieval were compared with 39 age-matched normal responders, requiring fewer than 50 ampoules. IGF-1 concentrations were determined by extraction radioimmunoassay on serum samples obtained after pituitary desensitization but prior to gonadotrophin stimulation. RESULTS: Despite highly significant differences in measures of ovarian response between groups, the mean serum IGF-1 concentration was not statistically significantly different between poor and normal responders {(31.5 nmol/l [95% confidence interval (CI) 28.5-34.5] versus 34.5 nmol/l (95% CI 31.8-37.2)} respectively. No correlation between oocyte number or total gonadotrophin used and serum IGF-1 concentration was observed. CONCLUSION: Whilst IGF-1 influences ovarian follicular development this study suggests that serum IGF-1 does not predict ovarian response and does not differentiate between critically-defined poor and normal responders.