Indication of OGTT: when is the test used?

OGTT stands for oral glucose tolerance test. After an initial blood sample, you drink a measured glucose solution and have further blood samples taken at planned intervals. The pattern of your glucose readings helps the maternity team assess how your body processes sugar. It is commonly discussed during antenatal care because pregnancy can change insulin needs.

Your clinician may recommend the test after a screening result needs clarification, or when your history or pregnancy care suggests that a more detailed glucose check would be useful. Being advised to have an OGTT does not by itself confirm diabetes.

Follow the instructions from your maternity team about fasting, medicines, and the appointment time. Plan to remain at the clinic during the testing period, since eating, drinking something other than the permitted water, or exercising can affect the readings. Bring a snack for afterwards if your clinic permits it, and tell staff if you feel dizzy, sick, or unwell during the test.

Ask how and when you will receive the result. A result outside the expected range may lead to advice about monitoring, food choices, or follow-up assessment rather than an immediate diagnosis.

Contact your maternity team promptly if you cannot keep fluids down, feel faint, or develop marked weakness while waiting for or completing the test. During pregnancy, seek urgent assessment for severe headache, vision changes, heavy bleeding, severe abdominal pain, or noticeably reduced fetal movement, regardless of whether an OGTT is planned.

Ask why the OGTT has been recommended, whether you need to fast, which medicines you should take, how long the appointment will last, and what follow-up will happen if a reading is outside the expected range.