What GCT value mandates OGTT?

GCT (50g 1-hour): ≥130 mg/dL = 90% sensitivity threshold (more testing); ≥140 mg/dL = 80% sensitivity (fewer OGTTs). Most centers use 130-135 mg/dL. GCT ≥200 mg/dL diagnoses GDM without OGTT.

What are IADPSG 75g OGTT criteria?

Any one value meets GDM: fasting ≥92 mg/dL, 1h ≥180 mg/dL, 2h ≥153 mg/dL. More permissive than Carpenter-Coustan, increasing GDM diagnosis rate from 5% to 15-20%. ACOG does not universally endorse IADPSG over 2-step approach.

What are Carpenter-Coustan 100g OGTT thresholds?

Fasting ≥95, 1h ≥180, 2h ≥155, 3h ≥140 (all in mg/dL). GDM diagnosed if ≥2 values met. NDDG thresholds are higher (105/190/165/145 mg/dL).

GDM Screening: GCT and OGTT Diagnostic Thresholds

Interpret 50g GCT and 100g 3-hour OGTT (Carpenter-Coustan or NDDG criteria) or 75g 2-hour OGTT (IADPSG/WHO criteria) for gestational diabetes mellitus (GDM) diagnosis. Two abnormal values on OGTT or any one value on IADPSG criteria.

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GDM Screening: GCT and OGTT Diagnostic Thresholds

Frequently Asked Questions

What GCT value mandates OGTT?

What are IADPSG 75g OGTT criteria?

What are Carpenter-Coustan 100g OGTT thresholds?