What screening test is performed to check for gestational diabetes?

The Oral Glucose Tolerance Test (OGTT) is the standard screening test used to diagnose gestational diabetes. This test is specifically designed to assess how well the body processes glucose during pregnancy. It typically involves the patient fasting overnight, then drinking a solution containing a high concentration of glucose, and subsequently having their blood glucose levels tested at intervals.

This method effectively measures the body's ability to manage glucose levels after consuming a significant amount of sugar, making it a reliable indicator of gestational diabetes. Women are usually screened for this condition between the 24th and 28th weeks of pregnancy, as the risk of developing gestational diabetes increases during this time.

While the fasting blood glucose test and the random blood glucose test can provide information about glucose levels, they are not as effective in diagnosing gestational diabetes as the OGTT since they don't evaluate the body's response to a glucose challenge. The HbA1c test, which measures average blood glucose levels over the previous two to three months, is not typically used for gestational diabetes screening because it does not reflect the acute changes in glucose metabolism that occur during pregnancy.