Continuous Glucose Monitoring for Screening for Diabetes in Pregnancy

Continuous Glucose Monitoring for Screening for Diabetes in Pregnancy:A Comparative Effectiveness Randomized Control Trial (PRECISE)

The purpose of this study is to evaluate whether Continuous glucose monitoring (CGM) for diagnosis of gestational diabetes mellitus (GDM) improves maternal and neonatal outcomes related to GDM and to evaluate whether CGM for GDM diagnosis reduces the health system costs for mother-infant dyads compared to usual care

Group I will be comprised of one-hour 50g glucose challenge participants for diagnosis of GDM..Diagnosis will be based on 1-hour glucose challenge test results: 1-hour result ≤ 130 mg/dL, the participant will have passed the challenge test. 1-hour result ≥ 130 mg/dL will complete a three-hour 100g glucose tolerance test. If two out of three values are elevated per Carpenter Coustan criteria , the participant will be diagnosed with GDM and treated according to the standard of care. This group will also receive the CGM.CGM data will not be observed until completion of study and will not be available to provider. Participants will return transmitter at follow up visit after completion of 7 days.Group I will receive routine prenatal care follow-up depending upon one-hour glucose results as written above.

CGM will consist of using the Dexcom G6 Pro device. The device will be placed on the abdomen or the arm.The Dexcom G6/G7 Pro App will be downloaded on the patient's phone. A patient profile will be created on the Dexcom Clarity portal .The patient will receive an email to link their portal to the clinic's portal.The patient will receive a message through Epic electronic medical records to remove the CGM 10 days after placement.The device will be reviewed by the Diabetes team 48 hours after CGM is removed. The recommended range for glucose during pregnancy is defined as 63-140 mg/dL .The time above range has been defined as ≥ 140 mg/dL, greater than 10% of total CGM placement time. The following criteria will currently be used to diagnose gestational diabetes in the CGM group: Time above range (≥140 mg/dL) ≥ 10% of the time while using CGM or Average glucose≥130 mg/dL or Any glucose value ≥200 mg/dL

Number of neonates that show Composite Adverse Neonatal Outcome such as Large for gestational age(LGA)

LGA is described as weight over 90th percentile of the expected value according to gestational age (using the nomogram by Duryea EL et al)

Shoulder dystocia is defined as the need for any extra maneuvers, other than gentle downward traction of the fetal head to deliver the fetal body after the fetal head has been delivered

Neonatal hypoglycemia: less than 40 mg/dL in the first 24 hours of life and less than 50 mg/dL after or requiring medical therapy

Respiratory distress is described as the need for at least 4 hours of respiratory support with supplemental oxygen, continuous positive airway pressure, or ventilation at the first 24 hours of life

Number of women with Postpartum hemorrhage: defined as greater then 1000ml or need for blood transfusion

Small for gestational age, defined as a weight below 10th percentile of the expected value according to gestational age (using the nomogram published by Duryea EL et al)

Inclusion Criteria: 24-30 weeks gestation undergoing GDM screening Exclusion Criteria: Known diagnosis of Type I and II DM History of bariatric surgery Major fetal anomalies Unwilling to use CGM for GDM screening Incarcerated subjects History of allergic reaction to any of CGM metals or adhesives in contact with the skin