Glucose monitoring approach in pregnancy for type 2 diabetes
STEP 1 — Gather Information
Confirm pregnancy, type 2 diabetes diagnosis, gestational age, current glucose monitoring method, patient preferences, access to CGM devices, insurance coverage, and ability to perform fingersticks. Review hypoglycemia awareness, insulin regimen, and any skin sensitivities or adhesive issues.
STEP 2 — Rule In / Rule Out
Rule out CGM if patient has significant skin allergy to adhesives, inability to operate the device, or lack of access/training. Rule out sole reliance on SMBG if patient experiences frequent hypoglycemia unawareness, high glycemic variability, or uses insulin pump/CGM-compatible technology.
STEP 3 — Classify or Stratify
Stratify by potential CGM benefit: consider CGM for those on intensive insulin therapy, with history of hypoglycemia, high postprandial excursions, or using insulin pump; consider SMBG for those with stable glucose on basal-only therapy, limited dexterity, or preference for fewer devices.
STEP 4 — Decide
If CGM is accessible and patient prefers real-time trends with alerts, initiate CGM with supplemental SMBG for calibration/confirmation; otherwise, prescribe SMBG fasting and pre/postprandial (typically 4 times daily) with individualized targets.
Clinical Guardrails / Mimics / Pitfalls
Do not rely on a single CGM glucose target <140 mg/dL; use pregnancy-specific fasting and postprandial targets. Avoid CGM without SMBG verification if sensor accuracy is questionable. Do not delay insulin adjustments awaiting CGM trends if symptomatic hypoglycemia occurs.
Concrete Clinical Example
A 30‑year‑old at 14 weeks gestation with T2DM on basal‑bolus insulin reports nocturnal hypoglycemia and variable postprandial spikes. She has insurance coverage for CGM and prefers fewer fingersticks. After training, she starts rtCGM with SMBG twice daily for calibration, targeting fasting <95 mg/dL and 1‑hour postprandial <140 mg/dL.
Source: Preexisting Diabetes and Pregnancy: An Endocrine Society and European Society of Endocrinology Joint Clinical Practice Guideline, 2025, DOI: 10.1210/clinem/dgaf288