Purpose: The objective of this proposal is to study the safety and efficacy of metformin added to insulin for treatment of type 2 diabetes mellitus (T2DM) among pregnant women. Participants: 950 pregnant women with type 2 diabetes complicating pregnancy from 10 U.S. clinical centers Procedures (methods): Pregnant women with T2DM between 10 weeks and 22 weeks 6 days and a singleton fetus will be randomized to double-blinded insulin/placebo versus insulin/metformin. Primary outcome is composite adverse neonatal outcome (clinically relevant hypoglycemia, birth trauma, hyperbilirubinemia, stillbirth/neonatal death). Study visits monthly at clinical visits; blood draw at 24-30 weeks, newborn anthropometric measurements at less than 72 hours of life. Maternal and infant outcomes will be chart abstracted.



Eligible Ages
Between 18 Years and 45 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Maternal age 18-45 years - Singleton pregnancy with no known fetal anomalies - Gestational age between 10weeks 0 days and 22 weeks 6 days by menstrual dating confirmed by ultrasound, or ultrasound alone - Clinical diagnosis of preexisting T2DM requiring medical treatment (oral agent or insulin) - Clinical diagnosis of diabetes diagnosed between 10 weeks and < 20 weeks 6 days gestation - Willing to start insulin therapy and discontinue oral hypoglycemic pills other than study pills - Able to swallow pills

Exclusion Criteria

  • Clinical diagnosis of pre-existing renal disease, defined as creatinine > 1.5 mg/dL - Clinical history of lactic acidosis - Known allergy to metformin - Participation in another study that could affect primary outcome - Delivery planned at non-MOMPOD study locations - Unwillingness to use insulin treatment or follow prenatal care doctor's instructions for insulin and blood glucose monitoring

Study Design

Phase 3
Study Type
Intervention Model
Parallel Assignment
Primary Purpose
Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)

Arm Groups

ArmDescriptionAssigned Intervention
Active Comparator
Metformin 1000 mg twice a day
  • Drug: Metformin
    1000 mg twice a day
    Other names:
    • Glumetza
    • Fortamet
    • Glucophage
    • Riomet
Sham Comparator
Placebo, identical to Metformin
  • Drug: Placebo
    Delivered to match active drug
    Other names:
    • Sugar pill

Recruiting Locations

University of Alabama
Birmingham, Alabama 35294
Lori Harper, MD

More Details

University of North Carolina, Chapel Hill

Study Contact

Amber Irvins
(919) 843-4420


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.