Metformin in women with type 2 diabetes in pregnancy (MiTy): a multicentre, international, randomised, placebo-controlled trial

Type Article

Journal Article


D. S. Feig; L. E. Donovan; B. Zinman; J. J. Sanchez; E. Asztalos; E. A. Ryan; I. G. Fantus; E. Hutton; A. B. Armson; L. L. Lipscombe; D. Simmons; J. F. R. Barrett; P. J. Karanicolas; S. Tobin; H. D. McIntyre; S. Y. Tian; G. Tomlinson; K. E. Murphy; D. Fei

Year of publication



The Lancet Diabetes and Endocrinology








Background: Although metformin is increasingly being used in women with type 2 diabetes during pregnancy, little data exist on the benefits and harms of metformin use on pregnancy outcomes in these women. We aimed to investigate the effects of the addition of metformin to a standard regimen of insulin on neonatal morbidity and mortality in pregnant women with type 2 diabetes. Methods: In this prospective, multicentre, international, randomised, parallel, double-masked, placebo-controlled trial, women with type 2 diabetes during pregnancy were randomly assigned from 25 centres in Canada and four in Australia to receive either metformin 1000 mg twice daily or placebo, added to insulin. Randomisation was done via a web-based computerised randomisation service and stratified by centre and pre-pregnancy BMI (