At what gestational age is the glucose tolerance test typically performed?

The glucose tolerance test is typically performed between 24 and 28 weeks of gestation because this period aligns with the onset of insulin resistance that occurs during pregnancy. As the placenta develops, it produces hormones that can impair insulin action, increasing the risk for gestational diabetes. The test screens for this condition to ensure that both the mother and baby remain healthy throughout the pregnancy. It is crucial to identify gestational diabetes early, as proper management can help prevent complications for both the mother and child. Conducting the test earlier in pregnancy, like at 12 weeks, does not effectively capture the rise in insulin resistance and is therefore not standard practice. Similarly, performing it later, at 32 or 36 weeks, may miss the optimal time to manage any potential glucose intolerance effectively.