Continuous glucose monitoring during pregnancy provides tighter glucose control with less hypoglycemia compared to fingersticks alone. Here is the evidence and practical guidance.
Why Tight Control Matters in Pregnancy
Hyperglycemia during pregnancy is associated with increased risk of macrosomia, preterm birth, and neonatal hypoglycemia. Targets during pregnancy are significantly tighter than outside pregnancy: typically 63-140 mg/dL (3.5-7.8 mmol/L) — a narrower range requiring more vigilance.
Evidence for CGM in Pregnancy
The CONCEPTT trial (2017) showed that CGM use in Type 1 diabetes during pregnancy reduced A1C, increased time in range, and reduced newborn complications including large-for-gestational-age babies and NICU admissions. This is the strongest evidence supporting CGM in this population.
Approved CGMs for Pregnancy (US, 2026)
- Dexcom G7: FDA approved for use in pregnancy. Recommended target range 63-140 mg/dL (set in the app).
- FreeStyle Libre 3: Not currently FDA approved for pregnancy. Some providers use it off-label.
Gestational Diabetes and CGM
For gestational diabetes, CGM is increasingly used though coverage varies. Evidence shows CGM reduces macrosomia risk in gestational diabetes compared to fingersticks. The GUARDIAN trial (2022) supports this use. Ask your OB or MFM specialist whether CGM is appropriate for your situation.
Sensor Placement in Pregnancy
As pregnancy progresses, abdominal sensor placement becomes less appropriate. The back of the upper arm remains the most reliable site throughout pregnancy. Adhesion may decrease due to increased perspiration in later trimesters — use Skin Tac or Simpatch overlays.
Medical Disclaimer
CGM management during pregnancy requires close collaboration with your obstetric and diabetes care team. This content is informational only. Glucose targets, insulin adjustments, and CGM interpretation should always be directed by your healthcare providers.