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Completed

NCT Number: NCT04803357

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.

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Key information

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

University of Washington

Seattle, Washington, 98109, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Pregnancy and Gestation < 30 weeks
  • Singleton pregnancy
  • Confirmed gestational diabetes (by 75g or 100g oral glucose tolerance test or HbA1c)
  • Able to read English and completed 6th grade
  • 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

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

Treatment and study plan

Continuous Glucose Monitor

Device

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.

Primary outcomes

  1. Mean Glucose

    Time frame: 36 weeks

    mean glucose CGM

  2. TIR CGM

    Time frame: 36 weeks

    Time in range, 63 - 140 mg/dL (TIR) by % continuous glucose monitoring

Secondary outcomes

  1. Fetal Birthweight

    Time frame: delivery

    Birth weight [grams; mean (SD)]

  2. TBR CGM GDM

    Time frame: 36 weeks

    Time below range, 63 mg/dL threshold (TBR63) GDM

  3. TAB CGM GDM

    Time frame: 36 weeks

    Time above range, 140 mg/dL threshold (TAR140)

  4. MAGE CGM

    Time frame: 36 weeks

    Mean Amplitude of glycemic excursions (MAGE) continuous glucoe monitoring

  5. SD CGM

    Time frame: 36 weeks

    standard deviation Continuous glucose monitoring

  6. CV CGM

    Time frame: 36 weeks

    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.

  7. Neonatal Hypoglycemia

    Time frame: delivery

    number(%) <40mg/dl of neonatal hypoglycemia

  8. Gestational Age at Delivery

    Time frame: delivery

    gestational age at delivery weeks mean (sd)

  9. Mode of Delivery

    Time frame: delivery

    mode of deliver reported ( vaginal, c-section, operative vaginal)

  10. Type of Labor

    Time frame: delivery

    Labor Status on Admission -(induced, spontaneous, planned c-section

  11. Shoulder Dystocia

    Time frame: delivery

    number with shoulder dystocia at delivery

  12. Preeclampsia or HTN

    Time frame: delivery

    Preeclampsia or Gestational hypertension (HTN )

  13. Maternal Weight Gain

    Time frame: delivery

    Maternal weight gain [lbs; mean (SD)] at delivery

  14. Diabetes Medication Use

    Time frame: at 36 weeks

    use of metformin and insulin in pregnancy

  15. 5 Minute Apgar

    Time frame: delivery

    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

  16. Live Birth or Stillbirth

    Time frame: devlivery

    live birth or still birth at delivery

  17. Birthweight Ratio

    Time frame: delivery

    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.

  18. NICU Admission

    Time frame: delivery

    Need for neonatal intensive care admission

  19. Neonatal Complications

    Time frame: delivery

    neonatal respiratory distress, birth injury, hypoxic encephalopathy

  20. Glucose Meter Fingerstick Per Day

    Time frame: 36 weeks

    mean number of fingersticks per day by 36 weeks

  21. Mean Days of RT-CGM Use

    Time frame: 36 weeks

    Mean (SD) days of RT-CGM use

  22. A1c

    Time frame: 36 weeks

    A1c at 36 weeks

  23. Fructosamine

    Time frame: 36 weeks

    frucosamine at 36 weeks

  24. Short Food Questionnaire

    Time frame: 36 weeks

    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

  25. WHO QOL Scale

    Time frame: 36 weeks

    World health organization Quality of Life survey Possible scores range from 0 to 25 with higher scores indicating more happiness or contentment.

  26. Diabetes Distress(PAID) Survey

    Time frame: 36 weeks

    5 items diabetes distress score Possible total score ranges from 0 to 20. Higher scores indicate more emotional distress.

  27. Walking Time Physcial Active Questionnaire

    Time frame: 36 weeks

    % of participants walking greater than 10 minutes or more per day

  28. Metformin Only Use

    Time frame: at 36 weeks

    use of metformin only

  29. Insulin Use Only

    Time frame: at 36 weeks

    use of insulin only

  30. Insulin Use Only

    Time frame: at delivery

    use of insulin only

  31. Diabetes Medication Use Delivery

    Time frame: at delivery

    use of metformin and insulin in pregnancy

  32. Metformin Use Only at Delivery

    Time frame: at delivery

    use of metformin only at time of delivery

Sponsors and collaborators

Lead sponsor

University of Washington

Other

Collaborators

  • DexCom, Inc.

Registry information

Important dates

Study start
2021
Primary completion
2024
Study completion
2025
First posted
Mar 17, 2021
Registry last updated
Jun 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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