DECIDE: A Comparative Effectiveness Trial of Metformin Versus Insulin for the Treatment of Gestational Diabetes

This is a non-inferiority patient-centered and pragmatic comparative-effectiveness pregnancy randomized controlled trial (RCT) with postpartum maternal and child follow-up through 2 years of 1,572 individuals with gestational diabetes mellitus (GDM) randomized to oral metformin versus injectable insulin. This study will determine if metformin is not inferior to insulin in reducing adverse pregnancy outcomes, is comparably safe for exposed individuals and children, and if patient-reported factors, including facilitators of and barriers to use, differ between metformin and insulin. A total of 1,572 pregnant individuals with GDM who need pharmacotherapy will be recruited at 20 U.S. sites using consistent treatment criteria to metformin versus insulin. Participants and their children will be followed through delivery to two years postpartum.

NCT Number	NCT06445946
Lead Sponsor	Ohio State University Collaborators: Patient-Centered Outcomes Research Institute, The George Washington University Biostatistics Center
Conditions	Gestational Diabetes Mellitus, Pregnancy, High Risk
Enrollment	1,572 participants
Start Date	2024-08-01
Primary Completion	2029-12 (estimated)
Study Completion	2030-12 (estimated)
Updated on ClinicalTrials.gov	2026-06-25