What do you understand by Glucose Screening test (Oral glucose challenge test)?

The glucose screening test is done to measure your body's response to sugar (glucose) during pregnancy. Glucose screening test or the oral glucose challenge test (GCT) is usually done between 24 and 28 weeks of pregnancy. This test is done to screen for gestational diabetes. Gestational diabetes is a type of diabetes that develops only in pregnant women.

For glucose screening test you will be given a sugary solution to drink. The drink contains 1.8 ounces (50 grams) of sugar and the quantity is about 8 ounces (237 milliliters). The blood sugar is measured after one hour.

The change in your blood sugar levels in response to sugary solution indicates whether you might have gestational diabetes. Based on the response to glucose challenge test one hour after drinking the glucose solution the result may be interpreted as;

• Normal: If the blood sugar level below 140 mg/dL (7.8 mmol/L)
• Gestational diabetes: If your blood sugar level is > 140 mg/dL (7.8 mmol/L)

A lower threshold of 130 mg/dL (7.2 mmol/L) is used by some labs and clinicians when screening for gestational diabetes.

If your test is positive your doctor may recommend additional tests to confirm the diagnosis.

Dr Poonam Sachdeva, our in-house medical expert talks about the why what and how in diabetes.

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