What is a glucose challenge test?
A glucose challenge test is given to pregnant women to see if she may have gestational diabetes. The glucose challenge test measures the amount of glucose (sugar) in the mother’s blood stream. The woman’s body is “challenged” by having the woman drink a glucose solution to see how her body reacts to the overload of glucose.
How is a glucose challenge test administered?
The pregnant the woman drinks a sugary beverage provided by the doctor or lab. Blood is drawn from the vein one hour later.
If the glucose level is over 140 mg/dL (7.8 mmol/L), the results are considered positive (abnormal) but not all women with a positive screening test have gestational diabetes.
This test may be performed at any time during the day.
Why are women given a glucose challenge test during pregnancy?
Most doctors routinely screen women for gestational diabetes because all women who become pregnant are at risk for developing gestational diabetes.
If a woman has gestational diabetes she will have elevated blood sugar (blood glucose). This can cause the baby to gain too much weight and may cause health problems for the mother.
Gestational diabetes can sometimes be treated with changes in lifestyle but many women will need to take insulin during her pregnancy.
In most cases, gestational diabetes resolves by itself after the baby is born. Some women remain diabetic after pregnancy and will then classified as having type 2 diabetes.
American Diabetes Association Guidelines for
Gestational Diabetes Screening: Glucose Challenge Test
|Blood glucose level 1 hour after drinking 50 grams of glucose||Indication|
|Less than 140* mg/dL (7.8 mmol/L)||Normal glucose tolerance|
|140 mg/dL or, (1) 7.8 mmol/L or higher||Abnormally elevated, woman needs an Oral Glucose Tolerance Test (OGTT)|
(1) Some physicians use a lower cutoff and may recommend that a
woman undergo an OGTT if she is 130 mg/dL (7.2 mmol/L) or higher.