OGT Gestational Diabetes and Pregnancy Testing 1 — Questions and Answers
Question 1: Which glucose load is used in the standard diagnostic OGTT for gestational diabetes in the United States?
- 50 g
- 75 g
- 100 g (Correct answer)
- 150 g
Correct answer: 100 g
The 3-hour 100 g OGTT is the standard diagnostic test for gestational diabetes (GDM) in the US per ACOG guidelines.
Question 2: What is the recommended screening week range for gestational diabetes testing in pregnant women without prior risk factors?
- 8–10 weeks
- 12–14 weeks
- 24–28 weeks (Correct answer)
- 32–34 weeks
Correct answer: 24–28 weeks
Universal gestational diabetes screening with a 50 g glucose challenge test or OGTT is recommended at 24–28 weeks of gestation.
Question 3: Which of the following is a risk factor that may prompt earlier GDM screening before 24 weeks?
- Age under 20
- First pregnancy
- Previous GDM in a prior pregnancy (Correct answer)
- Low pre-pregnancy BMI
Correct answer: Previous GDM in a prior pregnancy
Women with a history of gestational diabetes are at high risk of recurrence and should be screened early in subsequent pregnancies.
Question 4: What fasting glucose threshold (Carpenter-Coustan criteria) identifies gestational diabetes on a 100 g OGTT?
- ≥90 mg/dL
- ≥95 mg/dL (Correct answer)
- ≥105 mg/dL
- ≥126 mg/dL
Correct answer: ≥95 mg/dL
Under Carpenter-Coustan criteria, a fasting glucose of ≥95 mg/dL on the 100 g OGTT is one of the four diagnostic thresholds for GDM.
Question 5: How many abnormal values on the 100 g 3-hour OGTT are required to diagnose gestational diabetes (Carpenter-Coustan)?
- One
- Two (Correct answer)
- Three
- Four
Correct answer: Two
A diagnosis of GDM under Carpenter-Coustan criteria requires two or more abnormal values on the 4-point 100 g OGTT.
Question 6: What is the 1-hour glucose threshold in the 50 g glucose challenge test (GCT) that typically triggers a diagnostic OGTT?
- 120 mg/dL
- 130–140 mg/dL (Correct answer)
- 160 mg/dL
- 180 mg/dL
Correct answer: 130–140 mg/dL
A 1-hour glucose of 130–140 mg/dL on the 50 g GCT (threshold varies by institution) is considered screen-positive and warrants a full diagnostic OGTT.
OGT Gestational Diabetes and Pregnancy Testing 1
Which glucose load is used in the standard diagnostic OGTT for gestational diabetes in the United States?