A full adult dose should not be given to a person weighing less than 42.6 kg (94 lb), or the excessive glucose may produce a false positive result.

[citation needed] A 2020 study on pregnant women for gestational diabetes mellitus (GDM) found that 0-hour venous and capillary levels were similar, but that 2-hour samples were different.

The authors compared their study with others, and concluded that capillary samples could be used for diagnosis of GDM during pregnancy using corrected cutoffs with acceptable accuracy in an antenatal care setting.

[17] A standard two-hour GTT (glucose tolerance test) is sufficient to diagnose or exclude all forms of diabetes mellitus at all but the earliest stages of development.

[19] The oral glucose challenge test (OGCT) is a short version of the OGTT, used to check pregnant women for signs of gestational diabetes.

HOMA-IR (homeostatic model assessment) is a convenient way of measuring insulin resistance in normal subjects, which can be used in epidemiological studies, but can give erroneous results for diabetic patients.