Metformin and Gestational Diabetes in High-risk Patients: a RCTs

Gestational diabetes mellitus (DM) is one of the most frequent complications in pregnant patients with polycystic ovary syndrome (PCOS) in 20-40% of cases and \~40% of patients with gestational DM are likely to have underlying polycystic ovarian morphology. A recent meta-analysis demonstrated a significantly higher risk of developing gestational DM \[odds ratio (OR) 2.94; 95% confidence interval (CI): 1.70-5.08\] in the PCOS population. Metformin is an oral biguanide insulin sensitizer used for treating type-2 DM and recently introduced to treat PCOS. At the moment, preliminary data seem to reassure regarding the use of metformin in PCOS patients showing benefits for maternal and fetal outcomes, without serious adverse events. Furthermore, well-designed randomized, controlled trials (RCTs) on this issue are lacking, thus it is not possible to either suggest or advice against the use of metformin during pregnancy for reducing gestational DM risk. To this regard, PCOS represents an intriguing model of "high-risk patients" to evaluate the efficacy of metformin for preventing DM development. The present protocol firstly will evaluate the effects of metformin administration in reducing incidence of gestational DM in high-risk patients, such as pregnant PCOS patients.