The test itself
The 1-hour glucose challenge test (GCT): drink 50g of glucose solution, blood draw one hour later. No fasting required. This is a screen, not a diagnosis.
If your GCT result is over 140 mg/dL, you take the 3-hour glucose tolerance test (GTT). You must fast for this one. A single high number is not a GD diagnosis.
GD requires 2+ elevated values on the 3-hour test. Many women manage with diet and exercise alone. Needing medication is not a failure.
Who's at higher risk
Higher-risk groups: PCOS, family history of Type 2 diabetes, prior GD, BMI over 25, age 35+, South Asian, Black, Hispanic, or Indigenous heritage. Ask about early screening if these apply.
Unmanaged GD raises risk of large birth weight, C-section, shoulder dystocia, and newborn blood sugar issues. All manageable when caught early.
1 in 4 women who fail the 1-hour test passes the 3-hour. Push for the follow-up rather than accepting an immediate GD label off a single screen.