Glucose, Gestational Screen (50g), 140 Cutoff

Casandra

Casandra Test Code QD83956Version 1 (DRAFT)

Performing Lab

Lab Quest DiagnosticsLab Test ID 19833CPT Code 82950

Glucose, Gestational Screen (50g), 140 Cutoff

Also known as: Glucose, Gestational Screen, Gestational, Glucose

Clinical Use

Order Test

Use

This test is the first‐step screening test for gestational diabetes mellitus (GDM), typically performed between 24 and 28 weeks of pregnancy. It involves administration of a 50 g glucose load, with measurement of blood glucose one hour later. A result ≥ 140 mg/dL indicates abnormal glycemic response and the need for a diagnostic glucose tolerance test (e.g., 3‑hour OGTT)([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/about-our-tests/womens-health/pregnancy-and-fertility/pregnant-patients/testing-for-each-trimester?utm_source=openai)).

Special Instructions

Fasting is not required. The test is performed one hour after ingestion of a 50 g glucose beverage. It is supported by ACOG and ADA as the first step of the two‑step GDM evaluation([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/about-our-tests/womens-health/pregnancy-and-fertility/pregnant-patients/testing-for-each-trimester?utm_source=openai)).

Limitations

This screening test does not diagnose GDM—it identifies individuals at risk. False negatives may occur, particularly if performed under non‑standard conditions. Sensitivity and specificity vary; lower glucose cutoffs increase sensitivity but reduce specificity. Interpretation should be in clinical context, and abnormal results require follow‑up testing([uspreventiveservicestaskforce.org](https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/gestational-diabetes-screening?utm_source=openai)).

Test Details