What should you know about OGTT during pregnancy?

Pregnancy hormones can alter the way insulin works. During an OGTT, a fasting blood sample is followed by a glucose drink and timed samples. The test does not diagnose a problem from symptoms alone; the care team compares the results with the protocol used by the maternity service. If gestational diabetes is identified, support may include food guidance, glucose monitoring, and treatment tailored to you and the pregnancy.

Use the instructions from your maternity team about fasting, water, medicines, and arrival time. Do not deliberately change your usual meals beforehand unless instructed. Plan a quiet visit because you may need to stay for the timed samples. Tell the staff about vomiting, illness, medicines, or a previous difficulty with glucose testing before the drink is given.

Contact your maternity team if you have persistent vomiting, marked thirst, frequent urination, blurred vision, or unusual weakness. Seek urgent care for severe abdominal pain, heavy bleeding, fainting, severe breathing difficulty, confusion, or a seizure. These warning signs need assessment independently of the OGTT appointment.

Ask why the test is recommended, how to prepare, what to do with regular medicines, when results will arrive, and what support follows an abnormal result.