Screening
| Condition | 2 hour glucose | Fasting glucose | HbA1c |
|---|---|---|---|
| mmol/l(mg/dl) | mmol/l(mg/dl) | % | |
| Normal | <7.8 (<140) | <6.1 (<110) | <6.0 |
| Impaired fasting glycaemia | <7.8 (<140) | ≥ 6.1(≥110) & <7.0(<126) | 6.0–6.4 |
| Impaired glucose tolerance | ≥7.8 (≥140) | <7.0 (<126) | 6.0–6.4 |
| Diabetes mellitus | ≥11.1 (≥200) | ≥7.0 (≥126) | ≥6.5 |
A number of screening and diagnostic tests have been used to look for high levels of glucose in plasma or serum in defined circumstances. One method is a stepwise approach where a suspicious result on a screening test is followed by diagnostic test. Alternatively, a more involved diagnostic test can be used directly at the first antenatal visit in high-risk patients (for example in those with polycystic ovarian syndrome or acanthosis nigricans).
Non-challenge blood glucose test
|
| Screening glucose challenge test |
| Oral glucose tolerance test (OGTT) |
Non-challenge blood glucose tests involve measuring glucose levels in blood samples without challenging the subject with glucose solutions. A blood glucose level is determined when fasting, 2 hours after a meal, or simply at any random time. In contrast, challenge tests involve drinking a glucose solution and measuring glucose concentration thereafter in the blood; in diabetes, they tend to remain high. The glucose solution has a very sweet taste which some women find unpleasant; sometimes, therefore, artificial flavours are added. Some women may experience nausea during the test, and more so with higher glucose levels.
Read more about this topic: Gestational Diabetes