Oral glucose tolerance test to diagnose gestational diabetes mellitus: Impact of variations in specimen handling

Emma L. Jamieson, Goce Dimeski, Robert Flatman, Peter E. Hickman, Graham Ross Dallas Jones, Julia V Marley, H. David McIntyre, Alan R. McNeil, Christopher J. Nolan, Julia M. Potter, Arianne Sweeting, Peter Ward, Paul Williams, Andrea Rita Horvath

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


To improve birth outcomes, all pregnant women without known diabetes are recommended for an oral glucose tolerance test (OGTT) to screen for hyperglycaemia in pregnancy (diabetes in pregnancy or gestational diabetes mellitus (GDM)). This narrative review presents contemporary approaches to minimise preanalytical glycolysis in OGTT samples with a focus on GDM diagnosis using criteria derived from the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study. The challenges of implementing each approach across a diverse Australian healthcare setting were explored. Many Australian sites currently collect and transport OGTT samples at ambient temperature in sodium fluoride (NaF) tubes which is likely to lead to missed diagnosis of GDM in a significant proportion of cases. Alternative preanalytical solutions should be pragmatic and tailored to individual settings and as close as possible to the preanalytical conditions of the HAPO study for correct interpretation of OGTT results. Rapid centrifugation of barrier tubes to separate plasma could be suitable in urban settings provided time to centrifugation is strictly controlled. Tubes containing NaF and citrate could be useful for remote or resource poor settings with long delays to analysis but the impact on the interpretation of OGTT results should be carefully considered. Testing venous blood glucose at the point-of-care bypasses the need for glycolytic inhibition but requires careful selection of devices with robust analytical performance. Studies to evaluate the potential error of each solution compared to the HAPO protocol are required to assess the magnitude of misdiagnosis and inform clinicians regarding the potential impact on patient safety and healthcare costs.

Original languageEnglish
Pages (from-to)33-48
Number of pages16
JournalClinical Biochemistry
Early online date2022
Publication statusPublished - May 2023


Dive into the research topics of 'Oral glucose tolerance test to diagnose gestational diabetes mellitus: Impact of variations in specimen handling'. Together they form a unique fingerprint.

Cite this