Metformin Versus Standard of Care Treatment in Pregnant Women With Prediabetes

The purpose of this study is to assess if metformin reduces adverse outcomes associated with prediabetes in pregnancy. Our hypothesis is that pregnant women with prediabetes who are treated with metformin will show a greater reduction in large for gestational age infants at birth compared to women treated with the standard of care.

Women in pregnancy are routinely screened for diabetes in the first trimester and those who fall into the prediabetes category by hemoglobin A1c level of 5.7 to 6.4%, fasting plasma glucose of greater than or equal to 100 to 125, or oral glucose tolerance test of greater than or equal to 140 to less than 200 before 14 weeks gestation will be approached for consent in our randomized trial. Once consent is obtained, the subjects will be randomized 1:1 into two parallel groups, the metformin treatment group and the standard of care treatment group (routine prenatal care). A random number generator will allocate the participants to the study groups. Women taking metformin will continue twice daily dosing for the duration of their pregnancy after randomization. Those in the standard of care group will receive routine prenatal care. Both groups will undergo routine gestational diabetes testing by 28 weeks. Obstetric, maternal, and neonatal outcomes will then be assessed of both groups until the 6 week postpartum visit.

This is a prospective, single center, randomized study evaluating metformin in the treatment of pregnant women with prediabetes on maternal and neonatal outcomes.

Those assessing the outcomes from the medical chart will be blinded to the randomization process and the assigned study arm. Patients, the primary investigator, and their care providers will be aware of their treatment status.

Study subjects will be randomized to the metformin medication arm. They will take a 500 mg tablet orally twice a day starting at 14 weeks of pregnancy until delivery.

Study subjects will be randomized to standard of care and receive routine prenatal care without further intervention for their prediabetes.

Inclusion Criteria: Pregnant women with hemoglobin A1c of 5.7 to 6.4%, fasting plasma glucose of greater than or equal to 100 to 125, or oral glucose tolerance test of greater than or equal to 140 to less than 200 before 14 weeks gestation Pregnancy and delivery care obtained at University of Massachusetts (UMass) Memorial Medical Center Patients able to provide written informed consent Exclusion Criteria: Pre-existing diabetes diagnosis as assessed at visit in the first trimester by history or by laboratory evaluation as listed above Presence of contra-indication to metformin (liver, renal, or heart failure) or sensitivity to metformin Participants who are under the age of 18 Multiple Pregnancy Patients already taking metformin for other indications Fetal defect noted on early dating ultrasound Miscarriage before randomization

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