Continuous Glucose Monitoring (CGM) Substudy of the DECIDE RCT
Key facts
- Who runs it
- Ohio State University
- Where
- Boston, Columbus, Dayton, and Tuscaloosa, United StatesSee the 4 sites
- Trial code
- Status
- Withdrawn
- Started
- Sept 2025
- Expected to end
- Dec 2030
- Type of study
- Observational, 2 groups
- Treatments tested
- CGM device - Metformin group
- CGM device - Insulin group
- Record updated
- 28 October 2025
- Why it stopped
- We will focus on parent study
Who can take part
- Age
- 18 years and older
- Sex
- Women only
- Healthy volunteers
- Cannot take part
The registry criteria, word for word
Show all 18 criteriaShow less
Who can take part
- Singleton gestation. Twin reduction to singleton, either spontaneously or therapeutically, is eligible if it occurred before 14 weeks gestational age
- Age >18 years
- Gestational age at randomization between 200/7 - 316/7 weeks based on project gestational age
- GDM diagnosis between 200/7 - 316/7 weeks based on project gestational age
- Requires medication for glucose control defined as ≥30% elevated glucose values (either fasting or postprandial or both) in the week prior to randomization per determination of the provider or documented in the medical record
- Patient willingness and ability to attend 2-year follow-up visit
- Patient willingness to wear and return a blinded CGM device. It is possible that some enrolled individuals may choose to use a separate CGM device for glucose monitoring as part of clinical care
Who cannot take part
- Contraindication to metformin or insulin, including: history of lactic acidosis, intractable nausea and vomiting, prior documented allergy and/or anaphylaxis
- Pregestational diabetes documented in the medical record, GDM diagnosis <20 weeks, or prior A1c>6.5%
- Participation in this trial in a previous pregnancy. Patients who were screened in a previous pregnancy, but not randomized, may be included
- In addition, individuals who report a prior allergy or sensitivity to CGM will also be excluded
- Renal disease (serum creatinine >1.3 mg/dL) due to the potential impact of metformin on renal function
- Fasting hyperglycemia >115 mg/dl for ≥50% of fasting glucose values in the past week (due to the high risk of metformin failure with fasting hyperglycemia)
- Major structural malformation of the fetus
- Known fetal aneuploidy based on invasive testing or positive for aneuploidy on cell-free fetal DNA screening
- Enrolled in a trial that influences primary study outcomes of the parent DECIDE trial (composite neonatal outcome at delivery or childhood body mass index at 2 years)
- Prenatal care or delivery planned at a location where access to the complete electronic medical record will not be available to research staff
- Language barrier (appropriate translation resources unavailable at the site)
Where in United States
- Massachusetts General HospitalBoston, United States
- The Ohio State University Wexner Medical Center OB/GYN Maternal and Fetal MedicineColumbus, United States
- Premier Health - Miami Valley HospitalDayton, United States
- University of AlabamaTuscaloosa, United States
About the trial
What the trial wants to find out
This is a nested multicenter prospective cohort conducted concurrently and in conjunction with the DECIDE two-arm, pragmatic non-inferiority comparative effectiveness Randomized Controlled Trial (RCT) (NCT06445946) of metformin versus insulin among individuals with Gestational diabetes mellitus (GDM) requiring pharmacotherapy for glycemic control. Continuous Glucose Monitoring (CGM)-derived glycemic metric in pregnancy and postpartum will be compared between individuals randomized to metformin versus insulin. In addition, the association between CGM metrics and adverse pregnancy outcomes will be examined. Finally, whether CGM metrics can accurately identify diabetes postpartum compared with an oral glucose tolerance test and hemoglobin A1c will be determined. A total of 300 (150 metformin, 150 insulin) pregnant individuals will be recruited with GDM who require pharmacotherapy to use a blinded CGM device (Dexcom, Inc, San Diego, CA) at two pregnancy (medication randomization, late third trimester) and three postpartum timepoints (delivery, ~6 weeks, and ~2 years).
The 2 groups in the trial
- CGM device - Metformin
Individuals will be provided with a CGM device (Dexcom, Inc, San Diego, CA) to be worn for up to 10 days (minimum \>5 days) at two pregnancy (randomization to metformin or insulin, late third trimester \> 340/7 weeks) and three postpartum timepoints (immediately after delivery, \~6 weeks, and \~2 years). The CGM device will be used in blinded mode for both participants and providers (i.e., neither will be able to see glucose values).
Treatment: CGM device - Metformin group
- CGM device - Insulin
Individuals will be provided with a CGM device (Dexcom, Inc, San Diego, CA) to be worn for up to 10 days (minimum \>5 days) at two pregnancy (randomization to metformin or insulin, late third trimester \> 340/7 weeks) and three postpartum timepoints (immediately after delivery, \~6 weeks, and \~2 years). The CGM device will be used in blinded mode for both participants and providers (i.e., neither will be able to see glucose values).
Treatment: CGM device - Insulin group
Data and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Continuous Glucose Monitoring Among Individuals With Gestational Diabetes Treated With Metformin Versus Insulin: Protocol for a Nested Prospective Cohort in the DECIDE RCT (DECIDE CGM)
- Record updated
- 28 October 2025