Possible metformin effect on adrenal androgens during pretreatment and IVF cycle in women with polycystic ovary syndrome.

Objective: To determine the effects of metformin treatment on serum androgen levels ahead of and during the IVF cycle in infertile polycystic ovary syndrome (PCOS) women.

Design: A prospective, double-blind, placebo-controlled study.

Setting: Single-center, university IVF clinic.

Patients: Sixty-three PCOS women.

Intervention(s): Treatment with metformin 2,000 mg/day or identical placebo tablets for at least 14 weeks before and then during IVF treatment, ending on the day of hCG injection.

Main Outcome Measure(s): Serum levels of dehydroepiandrosterone, dehydroepiandrosterone sulphate (DHEAS), androstenedione, free testosterone index (FTI), dihydrotestosterone, and the androgen metabolite 5alpha-androstane-3alpha, 17beta-diol-glucuronide were measured at five time points ending on the day of ovum collection.

Result(s): During metformin pretreatment DHEAS increased, wheres other androgens were unaffected. During the IVF procedure androgens were unaffected by metformin treatment. Within 36 hours after the study medication was withdrawn the levels of androstenedione and FTI increased in the metformin group, whereas DHEAS decreased.

Conclusion(s): In infertile PCOS women metformin treatment increased DHEAS levels. During the IVF cycle androgen levels were unaffected by metformin, whereas there was a "rebound" effect when stopping metformin treatment.