Is metformin a primary ovulatory agent in patients with polycystic ovary syndrome?

Insulin resistance is an important pathophysiological feature of the polycystic ovary syndrome (PCOS). Insulin resistance and its compensatory hyperinsulinemia contribute to the anovulation, hyperandrogenism, infertility and early pregnancy loss suffered by women with PCOS. Current evidence supports the role of metformin in the treatment of anovulation in PCOS, both in monotherapy and concomitantly with clomiphene in clomiphene-resistant patients. In addition, novel evidence suggests that insulin sensitizers may also play a role in reducing the risk of early pregnancy loss. The insulin-sensitizing agents available commercially include metformin, rosiglitazone and pioglitazone. Compared with the thiozolidinediones, metformin is the agent that has been most frequently studied in PCOS, and has the most favorable pregnancy safety profile. In conclusion, there is strong evidence supporting the use of metformin as a primary ovulatory agent in women with PCOS.