A 31-year-old pregnant woman at 24+0 weeks undergoes a 75 g oral glucose tolerance test (OGTT). Results: fasting glucose 90 mg/dL, 1-hour glucose 195 mg/dL, 2-hour glucose 148 mg/dL. Using IADPSG/WHO 2013 criteria, what is the diagnosis?
- A Gestational diabetes mellitus (GDM) ✓
- B Normal glucose tolerance
- C Overt (pre-existing) diabetes mellitus in pregnancy
- D Impaired fasting glucose only
Correct answer: A. Gestational diabetes mellitus (GDM)
Explanation
IADPSG/WHO 2013 thresholds for GDM diagnosis (one or more values met or exceeded): fasting ≥92 mg/dL, 1-hour ≥180 mg/dL, 2-hour ≥153 mg/dL. This patient's 1-hour glucose of 195 mg/dL exceeds the 180 mg/dL threshold, confirming GDM despite fasting (90 mg/dL) and 2-hour values (148 mg/dL) being below cut-offs. Overt diabetes requires fasting ≥126 mg/dL or 2-hour ≥200 mg/dL or random ≥200 mg/dL.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.