A Study on the Use of Real -Time Continuous Glucose Monitoring (RT-CGM) in Gestational Diabetes

The purpose of this study is to examine whether RT-CGM (real time continuous glucose monitoring) use improves glucose control, maternal outcomes, and fetal outcomes in patients diagnosed with gestational diabetes. Currently, there is very limited data on whether RT-CGM use helps patients diagnosed with gestational diabetes. By conducting this study, the investigator hopes to develop a deeper understanding of how use of a RT-CGM may affect glucose control in the gestational diabetes population.

Study Overview

• Status: Completed
• Conditions: Gestational Diabetes
• Intervention / Treatment: Device: Continuous glucose monitor

Detailed Description

Pregnant Participants diagnosed with gestational diabetes are being invited to take part in a research study because these participants are pregnant and have gestational diabetes. Participants will be offered an opportunity to wear a medical device that monitors blood sugars (glucose). This device is called a continuous glucose monitor (CGM). The CGM measures glucose levels through a tiny plastic filament that is inserted under the skin in the abdomen by a skin prick. Typically, participants cannot feel this device once it is inserted. If participants agree to participate in this study, participants will be randomly placed into one of two groups: (1) the intervention group or (2) the control group. Participants will have a 50% (1 out of 2) chance like a coin toss of being placed into either group. If participants are in the intervention group, they will wear a real-time continuous glucose monitoring device (RT-CGM). The RT-CGM will allow participants to see glucose levels in real time. The RT-CGM will send information about glucose levels to a phone or display device so participants may see the glucose at all times. If participants are in the control group, they will not be given a RT-CGM. Instead, participants will be given a blinded CGM device. You will not be able to view your blood sugar results on the blinded CGM device. If participants are in the control group, they will also be given a blood glucose meter to check glucose using finger sticks according to the recommendations of the provider.

• Study Type: Interventional
• Enrollment (Actual): 105
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98109
      • University of Washington

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Pregnancy and Gestation < 30 weeks
2. Singleton pregnancy
3. Confirmed gestational diabetes (by 75g or 100g oral glucose tolerance test or HbA1c)
4. Able to read English and completed 6th grade
5. Is able to read, understand, and sign the Informed Consent Form (ICF) and if applicable, an Authorization to Use and Disclose Protected Health Information form (consistent with Health Insurance Portability and Accountability Act of 1996 [HIPAA] legislation), communicate with the investigator, and understand and comply with protocol requirements

Exclusion Criteria:

1. Pre-gestational Type 1 or Type 2 diabetes.
2. Newly diagnosed overt-diabetes in pregnancy [HbA1c ≥ 48 mmol/mol (6.5%), fasting glucose ≥ 7.0 mmol/l, random glucose ≥ 11.1 mmol/l].
3. Pregnancies with established fetal anomalies (aside from echogenic intracardiac foci and/or renal pyelectasis) or possible preterm delivery secondary to maternal disease besides GDM
4. Known endogenous/exogenous Cushing's syndrome
5. Known chronic infections
6. Current use of any oral form of steroid medication
7. Already receiving continuous glucose monitoring (CGM)
8. History of bariatric surgery
9. Gestational Age less than 14 weeks -

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
No Intervention: Control : Blinded Continuous Glucose Monitoring (CGM); If you are in the control group, you will wear a continuous glucose monitor but it will be blinded during pregnancy.
Active Comparator: Intervention: Real Time -Continuous Glucose Monitoring (RT-CGM); Wearing RT- CGM during pregnancy	Device: Continuous glucose monitor; We are offering you an opportunity to wear a medical device that monitors your blood sugars (glucose). This device is called a continuous glucose monitor (CGM). The CGM measures glucose levels through a tiny plastic filament that is inserted under the skin in your abdomen by a skin prick. Typically, you cannot feel this device once it is inserted.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Glucose	mean glucose CGM	36 weeks
TIR CGM	Time in range, 63 - 140 mg/dL (TIR) by % continuous glucose monitoring	36 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fetal Birthweight	Birth weight [grams; mean (SD)]	delivery
TBR CGM GDM	Time below range, 63 mg/dL threshold (TBR63) GDM	36 weeks
TAB CGM GDM	Time above range, 140 mg/dL threshold (TAR140)	36 weeks
MAGE CGM	Mean Amplitude of glycemic excursions (MAGE) continuous glucoe monitoring	36 weeks
SD CGM	standard deviation Continuous glucose monitoring	36 weeks
CV CGM	Coefficient of variation, % (CV)The Coefficient of Variation (%CV) is calculated by dividing the glucose Standard Deviation by the mean glucose. The %CV is a standardized measure that assesses the magnitude of glucose variability. The larger the %CV, the larger the variability in CGM readings.	36 weeks
Neonatal Hypoglycemia	number(%) <40mg/dl of neonatal hypoglycemia	delivery
Gestational Age at Delivery	gestational age at delivery weeks mean (sd)	delivery
Mode of Delivery	mode of deliver reported ( vaginal, c-section, operative vaginal)	delivery
Type of Labor	Labor Status on Admission -(induced, spontaneous, planned c-section	delivery
Shoulder Dystocia	number with shoulder dystocia at delivery	delivery
Preeclampsia or HTN	Preeclampsia or Gestational hypertension (HTN )	delivery
Maternal Weight Gain	Maternal weight gain [lbs; mean (SD)] at delivery	delivery
Diabetes Medication Use	use of metformin and insulin in pregnancy	at 36 weeks
5 Minute Apgar	5 minute apgar score A 5-minute Apgar score is a quick assessment of a newborn's overall health, particularly their ability to transition to life outside the womb. It's a score between 0 and 10, with each component (appearance, pulse, grimace, activity, and respirations) receiving a score of 0, 1, or 2. A score of 7-10 is considered reassuring, while scores below 7 may indicate the need for medical attentio	delivery
Live Birth or Stillbirth	live birth or still birth at delivery	devlivery
Birthweight Ratio	Birthweight ratio Birth weight ratio is defined as the ratio of observed birth weight divided by the median birth weight of the population-specific reference growth curve (based on 50% weight for gestational age). It is used to compare the birth weight of a fetus to the median for its gestational age. Higher birth weight ratios indicate larger fetuses for their gestational age, while lower ratios indicate smaller fetuse.	delivery
NICU Admission	Need for neonatal intensive care admission	delivery
Neonatal Complications	neonatal respiratory distress, birth injury, hypoxic encephalopathy	delivery
Glucose Meter Fingerstick Per Day	mean number of fingersticks per day by 36 weeks	36 weeks
Mean Days of RT-CGM Use	Mean (SD) days of RT-CGM use	36 weeks
A1c	A1c at 36 weeks	36 weeks
Fructosamine	frucosamine at 36 weeks	36 weeks
Short Food Questionnaire	starting the conversation food questionnaire Possible scores range from 0 to 16 with lower scores indicating better nutrition including more fruits and vegtables, and less or no sugared beverages.. The most healthful answer for each question is scored 0. The less healthful answer is scored 1. The least healthful answer is scored 2. To get a total score, add up the individual item scores. The total score ranges from 0 to 16. Lower scores indicate better nutrition	36 weeks
WHO QOL Scale	World health organization Quality of Life survey Possible scores range from 0 to 25 with higher scores indicating more happiness or contentment.	36 weeks
Diabetes Distress(PAID) Survey	5 items diabetes distress score Possible total score ranges from 0 to 20. Higher scores indicate more emotional distress.	36 weeks
Walking Time Physcial Active Questionnaire	% of participants walking greater than 10 minutes or more per day	36 weeks
Metformin Only Use	use of metformin only	at 36 weeks
Insulin Use Only	use of insulin only	at 36 weeks
Insulin Use Only	use of insulin only	at delivery
Diabetes Medication Use Delivery	use of metformin and insulin in pregnancy	at delivery
Metformin Use Only at Delivery	use of metformin only at time of delivery	at delivery

Collaborators and Investigators

• Sponsor: University of Washington
• Collaborators: DexCom, Inc.
• Investigators: Principal Investigator: Nicole M Ehrhardt, MD, University of Washington

Study record dates

Study Major Dates

• Study Start (Actual): April 10, 2021
• Primary Completion (Actual): October 1, 2024
• Study Completion (Actual): January 15, 2025

Study Registration Dates

• First Submitted: November 29, 2020
• First Submitted That Met QC Criteria: March 16, 2021
• First Posted (Actual): March 17, 2021

Study Record Updates

• Last Update Posted (Estimated): June 25, 2025
• Last Update Submitted That Met QC Criteria: June 6, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• 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
• Other Study ID Numbers: STUDY00011755

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

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.: No