G.T.T post 1 hour sugar for gestational diabetes is >__ mg%?
**Core Concept**
Gestational diabetes mellitus (GDM) is a condition of hyperglycemia that develops during pregnancy, typically after 24 weeks of gestation. The diagnosis and management of GDM often rely on the results of glucose tolerance tests (GTTs), which assess the body's ability to regulate blood glucose levels.
**Why the Correct Answer is Right**
The World Health Organization (WHO) and the American College of Obstetricians and Gynecologists (ACOG) recommend a 75-g oral glucose tolerance test (OGTT) for diagnosing GDM. For a 1-hour post-glucose challenge, a plasma glucose level of 180 mg/dL or higher is considered abnormal, indicating impaired glucose tolerance. The 1-hour value is a key indicator of potential GDM, and a value above 180 mg/dL warrants further evaluation.
**Why Each Wrong Option is Incorrect**
**Option A:** 140 mg/dL - This value is below the threshold for impaired glucose tolerance and would likely be seen in a healthy individual without GDM.
**Option C:** 220 mg/dL - While this value is significantly elevated and would suggest impaired glucose tolerance, it is not the exact value recommended by the WHO and ACOG for a 1-hour post-glucose challenge.
**Option D:** 160 mg/dL - This value is close to the threshold but does not meet the criteria for impaired glucose tolerance as per the recommended guidelines.
**Clinical Pearl / High-Yield Fact**
The 75-g OGTT is a widely used screening test for GDM, but it's essential to remember that a single value may not accurately diagnose GDM. A diagnosis is typically made based on the results of the 1-hour, 2-hour, and 3-hour post-glucose challenges.
**Correct Answer: C. 200 mg%**