Study was not funded and could not be performed

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.

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

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.