A 28-year-old G2P1 at 26 weeks undergoes a 75g oral glucose tolerance test (OGTT). Her results: fasting 88 mg/dL, 1-hour 192 mg/dL, 2-hour 158 mg/dL. Using IADPSG/WHO 2013 criteria, which diagnosis applies?
- A Normal glucose tolerance in pregnancy
- B Diabetes in pregnancy (overt diabetes)
- C Gestational diabetes mellitus (GDM) ✓
- D Impaired fasting glucose — no further action needed
Correct answer: C. Gestational diabetes mellitus (GDM)
Explanation
IADPSG (2010) and WHO 2013 criteria for GDM diagnosis during pregnancy (24–28 weeks) using 75g OGTT: fasting ≥ 92 mg/dL (5.1 mmol/L), 1-hour ≥ 180 mg/dL (10.0 mmol/L), 2-hour ≥ 153 mg/dL (8.5 mmol/L) — any ONE value meeting or exceeding threshold diagnoses GDM. This patient's 1-hour value of 192 mg/dL exceeds the 180 mg/dL threshold, diagnosing GDM despite a normal fasting and borderline 2-hour value. Overt diabetes in pregnancy requires fasting ≥ 126 mg/dL or 2-hour ≥ 200 mg/dL or random glucose ≥ 200 mg/dL with symptoms.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.