CGM for Management of Type 2 Diabetes in Pregnancy (CGM2)

Continuous Glucose Monitoring for Management of Type 2 Diabetes in Pregnancy

The goal of this clinical trial is to learn if continuous glucose monitoring works better than self-monitoring of blood glucose (fingersticks) to treat type 2 diabetes in pregnancy. It will also learn about all risk factors (biologic, personal, social) for maternal and infant complications in type 2 diabetes pregnancies. The main questions it aims to answer are:

1. Does continuous glucose monitoring improve infant outcomes compared to self-monitoring of blood glucose?
2. Does continuous glucose monitoring improve maternal diabetes control and other maternal outcomes compared to self-monitoring of blood glucose?
3. What other factors increase the risk of maternal and infant complications?

Participants will:

1. Use continuous glucose monitoring or self-monitoring of blood glucose to monitor blood sugar control from enrollment until delivery
2. Have blood drawn at enrollment, 24 weeks, 34 weeks and delivery to measure hemoglobin A1c levels and store blood for future analysis
3. Complete surveys about social support, environmental stressors, diabetes distress and glucose monitoring satisfaction at research visits
4. Have umbilical cord blood collected at delivery for analysis

Study Overview

• Status: Recruiting
• Conditions: Pregnancy; Type 2 Diabetes Mellitus (T2DM)
• Intervention / Treatment: Device: CGM

Detailed Description

We will conduct a multicenter, open-label randomized controlled trial of pregnant individuals with T2DM to test the effectiveness of CGM at improving maternal and neonatal outcomes, compared to SMBG. All pregnant women who have T2DM will be screened for eligibility. If a patient is eligible, the study will be explained to them and if they consent to participate, they will be randomized centrally in a 1:1 ratio to CGM or SMBG.

Participants randomized to CGM will receive a Dexcom G7 CGM and be instructed how to apply it, access the CGM data, and how to interpret and respond to trend arrows and alerts. Participants will replace the CGM device with a new sensor every 10 days for the entire pregnancy. Participants randomized to SMBG will be instructed to perform SMBG at least 4 times daily (fasting and 1-hour or 2-hours postprandial) and share their glucose data with their provider according to standard care. In order to collect comparable assessments of glycemic control between the groups, participants randomized to SMBG will wear a masked CGM for 10 days after randomization (Visit 1) and after Visits 2 (24 weeks) and Visit 3 (34 weeks). All participants will be provided a glucometer if they do not already have one and will have HbA1c and maternal serum collected at enrollment (6-22 weeks) and all study visits (24 weeks, 34 weeks, and delivery).

We will utilize ACOG and ADA recommendations for glycemic targets in pregnancy a standardized protocol with graduated goals for glycemic control to ensure consistency across arms and study sites. For pregnant individuals randomized to CGM, the target range will be 63-140mg/dL. For pregnant individuals randomized to SMBG, the targets will be fasting <95mg/dL, 1-hour postprandial less than 140mg/dL and 2-hour postprandial less than 120mg/dL. CGM reports and glucose logs will be reviewed at least every 1-2 weeks, and therapy adjustments (insulin, metformin, diet and/or lifestyle) will be recommended if less than 70% of glucose values are at target, regardless of the method of glucose monitoring. Additional therapy adjustments will be encouraged to achieve greater than 70% glucose values at target so long as there is not significant hypoglycemia (i.e. greater than 4%).

Telehealth visits may be utilized in addition to outpatient in person visits at the discretion of the provider, but should be used similarly for the CGM and SMBG groups. This protocol for glycemic management will be followed at all times including both at outpatient visits and during inpatient antepartum hospitalization. Intrapartum glycemic control, fetal testing and timing and route of delivery will be determined by the clinical provider in accordance with ACOG recommendations. After birth, umbilical cord blood will be collected for metabolic analyses, and neonates will have a heelstick performed to measure capillary blood glucose as part of usual care given maternal T2DM. Additional care including NICU admission and treatment of hypoglycemia will be at the discretion of the neonatal provider.

Validated screening tools to assess different SDoH domains will be administered at the first 2 study visits. At enrollment, each participant will be administered the Protocol for Responding to and Assessing Patient Assets, Risks and Experiences (PRAPARE) survey, a validated screening tool designed to identify SDoH including personal factors, family and housing, money and resources, and social and emotional health and safety. The home address provided will be used to calculate SVI and area deprivation index (ADI), a measure created to assess socioeconomic disadvantage at a neighborhood level based on income, education, employment and housing quality. Participants will complete the U.S. Adult Household Food Security Survey Module (HFSSM), a 10-item self-report questionnaire aimed at assessing food security over the prior 12 months as food insecurity may be associated with adverse outcomes. Participants will also complete the Type 2 Diabetes Distress Assessment System (T2-DDAS), a 29-item survey designed to identify the overall amount of DM-related distress as well as the sources of stress including hypoglycemia, long-term health, healthcare provider, interpersonal issues, shame or stigma, healthcare access, and management demands. At visit 2, participants will complete the Short Assessment of Health Literacy (SAHL) and the Diabetes Numeracy Test 15 (DNT15) given association between lower educational attainment and health literacy and numeracy with worse outcomes. Participants will also complete the Multidimensional Scale of Perceived Social Support (MSPSS), the only self-reported measure in a study of psychosocial stress associated with adverse pregnancy outcomes and the Experiences of Discrimination (EOD) scale, a 9-item self-report about lifetime experiences of discrimination attributed to race, ethnicity or skin color. At delivery, participants will repeat the T2-DDAS to assess if CGM impacted DM distress and complete a Glucose Monitoring Satisfaction Survey (GMSS), a validated tool to assess satisfaction with the assigned method of glucose monitoring.

• Study Type: Interventional
• Enrollment (Estimated): 564
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ashley Battarbee, MD, MSCR; Phone Number: 205-975-2361; Email: anbattarbee@uabmc.edu

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35233
      • Recruiting
      • University of Alabama at Birmingham
      • Contact: Ashley Battarbee; Phone Number: 205-975-2361; Email: anbattarbee@uabmc.edu
  • California
    • San Diego, California, United States, 92121
      • Recruiting
      • University of California at San Diego
      • Contact: Gladys Ramos, MD; Phone Number: 858-657-7200; Email: gramos@health.ucsd.edu
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • Recruiting
      • University of North Carolina - Chapel Hill
      • Contact: Kim Boggess, MD; Phone Number: 919-966-2131; Email: kim_boggess@med.unc.edu
  • Oregon
    • Portland, Oregon, United States, 97213
      • Recruiting
      • Oregon Health and Science University
      • Contact: Amy Valent, DO, MCR; Phone Number: 503-418-4200; Email: valent@ohsu.edu
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Recruiting
      • University of Pennsylvania
      • Contact: Celeste Durnwald, MD; Phone Number: 800-789-7366; Email: celeste.durnwald@pennmedicine.upenn.edu
  • South Carolina
    • Greenville, South Carolina, United States, 29605
      • Recruiting
      • Prisma Health Greenville Memorial Hospital
      • Contact: Daniel Pasko, MD; Phone Number: 864-455-7000; Email: daniel.pasko@prismahealth.org
  • Texas
    • Houston, Texas, United States, 77030
      • Recruiting
      • University of Texas Health Science Center at Houston
      • Contact: Michal Fishel Bartal, MD; Phone Number: 832-325-7133; Email: michal.f.bartal@uth.tmc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Type 2 diabetes mellitus treated with daily insulin injections or oral hypoglycemic agents diagnosed before pregnancy or at less than 14 weeks gestation with hemoglobin A1c 6.5% or greater
• Pregnant with viable fetus at 6 to less than 23 weeks gestation
• Maternal age 18-50 years old

Exclusion Criteria:

• Unable or unwilling to wear CGM due to intolerance to medical-grade adhesives or skin conditions
• Multiple gestation
• Major fetal anomaly or two or more minor fetal anomalies
• Planned delivery outside study consortium
• Participating in another conflicting interventional study
• Participation in this trial in a previous pregnancy
• Patient unable to consent
• Physician refusal for other reasons

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Continuous Glucose Monitoring; Real-time continuous glucose monitoring	Device: CGM; Real-time continuous glucose monitoring
No Intervention: Self-Monitoring of Blood Glucose; Self-monitoring of blood glucose (standard of care)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time in Range (TIR) at 34 weeks gestation	Percentage of time spent within target range (63-140mg/dL) on Continuous Glucose Monitoring at 34 weeks gestation	33 to 35 weeks gestation
Composite Neonatal Morbidity	Composite morbidity of the neonate including one or more of preterm birth (delivery less than 37 weeks for any indication), birth trauma (shoulder dystocia with nerve injury, clavicular or humeral fracture or 3 or more maneuvers to resolve), hypoglycemia (requiring treatment with dextrose gel or IV within 24 hours of birth), hyperbilirubinemia (requiring phototherapy within 72 hours of birth), large-for-gestational-age infant (birthweight greater than the 90th percentile for gestational age), and miscarriage, stillbirth or neonatal death prior to hospital discharge.	From the date of delivery to the date of neonatal hospital discharge, assessed up to 12 months of life

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Preterm birth	Delivery less than 37 weeks gestation	Delivery
Birth trauma	Shoulder dystocia with nerve injury, clavicular or humeral fracture or 3 or more maneuvers to relieve	Delivery
Neonatal hypoglycemia	Low neonatal glucose requiring treatment with dextrose gel or IV within 24 hours of life	Delivery to 24 hours of life
Hyperbilirubinemia	Elevated bilirubin requiring phototherapy within 72 hours of life	Delivery to 72 hours of life
Large-for-gestational-age (LGA) neonate	Birthweight greater than the 90th percentile for gestational age	Delivery
Small-for-gestational-age (SGA) neonate	Birthweight less than the 10th percentile for gestational age	Delivery
Fetal glucose	Concentration of umbilical cord blood glucose (mg/dL)	Delivery
Fetal insulin	Concentration of umbilical cord blood insulin (uU/mL)	Delivery
Fetal C-peptide	Concentration of umbilical cord blood C-peptide (ng/mL)	Delivery
Fetal leptin	Concentration of umbilical cord blood leptin (ng/mL)	Delivery
Fetal ghrelin	Concentration of umbilical cord blood ghrelin (uU/L)	Delivery
Fetal surfactant protein D	Concentration of umbilical cord blood surfactant protein D (ng/mL)	Delivery
Time Above Range (TAR) at 34 weeks	Percentage of time spent above range greater than 140mg/dL on Continuous Glucose Monitoring (CGM) at 34 weeks	33 to 35 weeks
Time Below Range (TBR) at 34 weeks	Percentage of time spent below range less than 63mg/dL on Continuous Glucose Monitoring at 34 weeks	33 to 35 weeks
Mean glucose at 34 weeks	Average glucose in mg/dL using Continuous Glucose Monitoring data at 34 weeks	33 to 35 weeks
Glucose Management Indicator (GMI)	Glucose management indicator as an estimate of hemoglobin A1c calculated using mean glucose on CGM at 34 weeks	33 to 35 weeks
Glucose variability at 34 weeks	Coefficient of variation calculated as the mean glucose divided by standard deviation using Continuous Glucose Monitoring data at 34 weeks	33 to 35 weeks
Mean fasting glucose at 34 weeks	Average glucose at 6-7am on Continuous Glucose Monitoring at 34 weeks	33 to 35 weeks
Hemoglobin A1c at Delivery	Hemoglobin A1c (%) at delivery	Delivery
Insulin total daily dose at delivery	Total number of units of insulin taken per day at time of delivery	Delivery
Cesarean delivery	First cesarean delivery or cesarean delivery after a history of prior cesarean	Delivery
Glucose Monitoring Satisfaction	Score on glucose monitoring satisfaction survey at delivery	Delivery
Fetal or neonatal death	Miscarriage (pregnancy loss less than 20 weeks), stillbirth (fetal death at 20 weeks or more), or neonatal death (death after birth up to 28 days of life)	From the date of randomization to the date of neonatal hospital discharge, assessed up to 12 months of life
Neonatal Intensive Care Unit (NICU) Admission	Admission to the neonatal intensive care unit with length of stay greater than 24 hours	From the date of delivery to the date of neonatal hospital discharge, assessed up to 12 months of life
Neonatal length of stay	Duration of neonatal hospitalization after delivery	From the date of delivery to the date of neonatal hospital discharge, assessed up to 12 months of life
Neonatal mechanical ventilation	Neonate requiring intubation and mechanical ventilation for respiratory support	From the date of delivery to the date of neonatal hospital discharge, assessed up to 12 months of life
Insulin increase during pregnancy	Percentage change in total daily dose of insulin at delivery compared to enrollment	From the date of randomization to the date of delivery, assessed up to 9 months
Preeclampsia	Elevated blood pressure greater than 140/90 mmHg after 20 weeks gestation with proteinuria or other severe features by ACOG criteria (may be superimposed on chronic hypertension or not)	From the date of randomization to the date of maternal hospital discharge after delivery, assessed up to 9 months
Postpartum infection	Developing one or more of endometritis, wound infection or other wound complication such as seroma, hematoma or dehiscence)	From the date of delivery through 6 weeks' postpartum
Glucose Monitoring Adherence	Defined as percentage of expected self-monitoring of blood glucose (SMBG) values completed based on recommended 4 values per day for participants in the SMBG arm and percentage of time Continuous Glucose Monitoring (CGM) in use in the CGM arm	From the date of randomization to the date of delivery, assessed up to 9 months

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); National Institutes of Health (NIH)
• Investigators: Principal Investigator: Ashley Battarbee, MD, MSCR, University of Alabama at Birmingham

Publications and helpful links

General Publications

• Padgett CE, Ye Y, Champion ML, Fleenor RE, Orfanakos VB, Casey BM, Battarbee AN. Continuous Glucose Monitoring for Management of Type 2 Diabetes and Perinatal Outcomes. Obstet Gynecol. 2024 Nov 1;144(5):677-683. doi: 10.1097/AOG.0000000000005609. Epub 2024 May 23.

Study record dates

Study Major Dates

• Study Start (Actual): April 8, 2025
• Primary Completion (Estimated): February 1, 2029
• Study Completion (Estimated): July 1, 2029

Study Registration Dates

• First Submitted: September 25, 2024
• First Submitted That Met QC Criteria: October 3, 2024
• First Posted (Actual): October 8, 2024

Study Record Updates

• Last Update Posted (Actual): June 15, 2025
• Last Update Submitted That Met QC Criteria: June 11, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Diabetes; Pregnancy; CGM
• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolic Diseases; Pregnancy Complications; Glucose Metabolism Disorders; Diabetes, Gestational; Diabetes Mellitus, Type 2; Diabetes Mellitus; Pregnancy in Diabetics
• Other Study ID Numbers: IRB-300013640; 1R01HD113612 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

All data produced in the course of the project will be preserved and shared including:

1. Recruitment rates, reasons for refusal, adherence, loss to follow up
2. Demographics and clinical data
3. Glucose and laboratory values
4. Satisfaction and survey responses

• IPD Sharing Time Frame: Data will be made available at the time of publication or the end of the funding period, whichever comes first.
• IPD Sharing Access Criteria: Deidentified individual patient data will be deposited in the NICHD DASH repository with public access. There is no planned requirement for data use agreements at this time; however, we will monitor the sensitive nature of study data collected at each of the participating sites and revise if needed during the conduct of the trial.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes