OBJECTIVE: To familiarize obstetrician–gynecologists with the use of metformin for the treatment of polycystic ovary syndrome (PCOS).
DATA SOURCES: Using OVID, 94 English-language articles published after 1966 indexed with the key words “metformin” and “polycystic ovary syndrome” were identified.
METHODS OF STUDY SELECTION: Studies were excluded if they did not have a control group, did not use the National Institutes of Health definition of PCOS, did not have a clinical outcome as an end point, and were not in the English language. Reviews were also excluded, leaving 21 articles for inclusion.
TABULATION, INTEGRATION, AND RESULTS: Three clinical trials reported that for the treatment of anovulatory infertility caused by PCOS, metformin plus clomiphene is more effective than clomiphene alone in inducing ovulation. For the treatment of irregular menses caused by PCOS in women not attempting conception, metformin therapy may restore ovulatory menses in the majority of women. However, most women will require 4–6 months of metformin therapy before they achieve ovulatory menses. In obese women, metformin plus a low-calorie diet may be associated with more weight loss than a low-calorie diet alone.
CONCLUSION: Polycystic ovary syndrome is a common gynecologic endocrine disorder. Obstetrician–gynecologists should be familiar with the indications and contraindications for the use of metformin in their practice.