Relationship between serum estradiol concentration and IGF-I, IGF-II and IGF-binding proteins in patients with premature ovarian failure on short-term estradiol therapy.

Objective: Insulin-like growth factors (IGFs) exert stimulatory effects on follicular growth and development, and early embryogenesis. In view of this, we studied the effect of short-term estradiol treatment, as used in preparing the uterus for embryo implantation, on the serum concentrations of IGFs and their binding proteins (IGFBP) in patients with premature ovarian failure (POF).

Patients and methods: Twenty-four patients with POF, enrolled in an assisted reproduction program, were treated with increasing doses of estradiol up to 8 mg daily for 6 weeks. Blood was sampled for measurement of serum estradiol, IGF-I, IGF-II, and IGFBP 1, 2 and 3 at various times during estradiol treatment.

Results: There was no significant correlation between serum estradiol concentrations and the serum concentrations of IGF-I and IGF-II. As expected, IGF-I and IGF-II concentrations in serum correlated positively with the serum concentration of IGFBP-3, the major IGF-binding protein in serum.

Conclusion: The results of this study suggest that estradiol therapy as used to prepare the uterus for implantation has no significant effect on serum IGF-I and IGF-II concentrations, and therefore probably does not influence, via an IGF-mediated mechanism, the success of implantation and early embryonic development.