CGM for the Early Detection and Management of Hyperglycemia in Pregnancy

Management will include an unblinded CGM sensor worn 24/7, GDM specific nutrition information, training on using CGM in daily glucose management to achieve euglycemia (maximizing time 63-140 mg/dL \[3.5-7.8 mmol/L\]). Visits (which could be telehealth) per usual obstetrical care for glycemia management (expected to be about every 4 weeks for most participants) and weekly glycemic management with review of CGM data by site and by central CGM Resource Center for flagged cases. Participants not receiving glucose lowering medication by 24-28 weeks will undergo OGTT per usual obstetrical management and those with positive OGTT will be treated for GDM per usual clinic routine and continue to wear an unblinded CGM.

The control group will receive usual obstetrical care at the clinical center. A general pregnancy nutrition information handout will be provided to each participant and a blinded CGM sensor will be placed at routine obstetrical care visits and worn for 10-14 days each time throughout the pregnancy beginning between 18-22 weeks' gestation. At 18-22 weeks, blinded CGM data will be reviewed to assess if participant has ≥25% time \>140 mg/dL to determine if an early OGTT or glycemic management is required. Site clinicians will be unblinded to the masked CGM data for participants with CGM data ≥25% time \>140 mg/dL and those participants may be treated as those with a positive OGTT. An OGTT will be performed at \~24-28 weeks per the clinic's usual routine and those with positive OGTT will be treated for GDM per usual clinic routine. If real-time CGM is to be used, then unblinded study CGM sensors can be used instead of blinded sensors for the duration of the study.