A 32-year-old woman at 28 weeks undergoes a 75g oral glucose tolerance test (OGTT). Results: fasting glucose 92 mg/dL, 1-hour 186 mg/dL, 2-hour 155 mg/dL. According to IADPSG (International Association of Diabetes and Pregnancy Study Groups) criteria adopted by WHO 2013, how is this diagnosed?

• A Impaired glucose tolerance only — does not meet GDM criteria as 2-hour value is slightly elevated
• B Normal — all three values are within acceptable ranges for pregnancy
• C Gestational diabetes mellitus (GDM) — one or more values at or above threshold (fasting ≥92, 1-hr ≥180, 2-hr ≥153) ✓
• D Overt diabetes mellitus requiring insulin from diagnosis

Explanation

IADPSG 2010 criteria (adopted by WHO 2013 and most Indian guidelines) use a one-step 75g OGTT. GDM is diagnosed if ANY ONE threshold is met or exceeded: fasting ≥92 mg/dL, 1-hour ≥180 mg/dL, or 2-hour ≥153 mg/dL. In this patient, the fasting value (92 mg/dL ≥92) and 2-hour value (155 mg/dL ≥153) both meet the threshold. 'Overt diabetes' is diagnosed when fasting ≥126 mg/dL or 2-hour ≥200 mg/dL or random ≥200 with symptoms. The Carpenter-Coustan criteria (used in the US with a two-step approach) uses different thresholds and requires two abnormal values — this is a key distinction.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.