At how many weeks gestation is a glucose tolerance test usually performed?

The glucose tolerance test is typically performed between 24 to 28 weeks of gestation. This timing is crucial because it corresponds with when pregnancy hormones can interfere with insulin action, leading to gestational diabetes. By conducting the test during this period, healthcare providers can effectively screen for gestational diabetes to ensure maternal and fetal health and intervene if necessary.

Testing too early, such as before 24 weeks, might not yield accurate results since some women might not exhibit glucose intolerance until later in pregnancy. Therefore, the recommended window allows for the best assessment of blood glucose levels under the influence of the changing hormonal environment of pregnancy.