The current status for metformin use in reproductive medicine

Metformin has been used extensively in multiple reproductive settings to ameliorate hyperandrogenism and chronic anovulation, to treat infertility, to prevent miscarriage and to prevent later pregnancy complications as well. Metformin does result in modest improvements in the PCOS phenotype with reductions in circulating insulin and testosterone levels, weight loss, and improved menstrual/ovulatory frequency. It is relatively ineffective as a solo agent to treat infertility, and further has a relative anti-fecundity compared to clomiphene alone. Clomiphene remains the first choice for infertility therapy and the gold standard for women with PCOS. Metformin may be useful in preventing OHSS when used in conjunction with gonadotropins. The use of metformin to prevent pregnancy loss or to prevent pregnancy complications is still experimental and better trials are needed to guide therapy.