Pregnancy glucose tolerance test (fasting)
What this test measures
The fasting value from the pregnancy glucose tolerance test, taken before the glucose drink. It is read against the pregnancy threshold, which is lower than outside pregnancy.
Why doctors request it
Offered at 24 to 28 weeks to women with risk factors for gestational diabetes, or earlier if there was gestational diabetes before.
What commonly pushes it up
- Gestational diabetes
- Pre-existing diabetes
- A shorter fast than requested
What commonly pushes it down
- A very long fast
Everyday reasons for a value outside the range
- The pregnancy threshold (5.6 mmol/L in NICE guidance) is lower than the 7.0 used outside pregnancy
- Different UK units use slightly different criteria
About the sample
Fasting from midnight; the two-hour value maps to the 2-hour glucose entry.
Upload a photo or PDF and see every line against the range your lab printed, explained in plain English. First report free.
Read my report freeThis is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.