Metformin use in patients undergoing in vitro fertilization treatment: results of a worldwide web-based survey

Responses from 101 centers performing a total of 50,800 annual IVF cycles was performed. Of these cycles, 10.4 % (n = 5,260) reported metformin use during IVF cycles. Indications for metformin use in IVF cycles included polycystic ovary syndrome (PCOS) patients who were habitual abortions (67 %), had prior poor egg quality (61 %), had high serum insulin levels (56 %). Less reported was PCOS with obesity/anvoulation (29 %), PCOS with multiple manifestations (23 %) and glucose intolerance and insulin resistance (23 %). Over half of cycles (54 %) treated patients with metformin up to 3 months prior to starting IVF. A majority (82 %) of IVF cycles utilized 1500–2000 mg/day of metformin. A nearly equal percentage of centers continued metformin up to a positive β-HCG test (35 %) or to 12 weeks gestation (33 %). 70 % of IVF cycles reported increased pregnancy rates and decreased miscarriage rates due to the use of metformin. 75 % reported the data in the literature is not sufficient for reaching a definitive conclusion concerning metformin treatment in patients undergoing IVF.