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GDM Diagnostic Criteria

GDM Diagnostic Criteria

IADPSG / WHO (2013) Standards

75g OGTT Thresholds

Fasting Plasma Glucose≥ 5.1 mmol/L

1-Hour Glucose≥ 10.0 mmol/L

2-Hour Glucose≥ 8.5 mmol/L

Diagnostic Rule

GDM is diagnosed if ANY ONE of the thresholds above is met or exceeded.

One-step 75g OGTT is performed at 24–28 weeks of gestation in women not previously diagnosed with overt diabetes.

Overt (Pre-existing) Diabetes: Fasting ≥ 7.0 mmol/L, HbA1c ≥ 6.5%, or Random Glucose ≥ 11.1 mmol/L.

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

Primary Clinical Uses

Universal screening for Gestational Diabetes Mellitus (GDM) between 24–28 weeks of gestation.

Early screening in the first trimester for high-risk patients (BMI > 30, history of GDM, strong family history) to identify overt pre-existing T2DM.

The Great Debate

There is a massive global divide between the "One-Step" approach (endorsed by WHO / IADPSG / ADA) and the "Two-Step" approach (endorsed by ACOG and NIH in the United States).

Last Comprehensive Review: 2026