The diagnosis of gestational diabetes mellitus (GDM) using a 75 g oral glucose tolerance test: A prospective observational study. (May 2020)

• Record Type: Journal Article
• Authors: O'Malley, E.G.; Reynolds, C.M.E.; O'Kelly, R.; McMahon, L.; Sheehan, S.R.; Turner, M.J.
• Is Part Of: Diabetes research and clinical practice. Volume 163(2020)
• Publication Date: 2020-05
• Subjects: Gestational diabetes mellitus -- Oral glucose tolerance test -- Diagnostic criteria -- Pregnancy; Diabetes -- Periodicals; Diabetes Mellitus -- Periodicals; 616.462
• DOI: 10.1016/j.diabres.2020.108144
• Languages: English
• ISSNs: 0168-8227

Abstract

Abstract: Aims: Screening for Gestational Diabetes Mellitus (GDM) is controversial. This prospective study compared different sets of diagnostic cut-off points for plasma glucose measurements following a 75 g Oral Glucose Tolerance Test (OGTT). Methods: Women who had maternal risk factors for GDM were recruited at their convenience at their first prenatal visit and consented to a one-step OGTT at 26–28 weeks gestation. All women fulfilling the World Health Organization (WHO) 2013 diagnostic criteria received standard care for GDM. Results: Of the 202 women, 139 (69%) had one risk factor for GDM and 63 (31%) had > 1. Using the WHO criteria, 53% (n = 108) had GDM compared with 35% (n = 71) using Canadian criteria and 18% (n=36) using National Institute for Health Care Excellence criteria (NICE) criteria (both p<0.001). Of the 108 women, 50% (n = 54) required pharmacological treatment to control hyperglycaemia. If the Canadian criteria were applied, 11/54 (20.4%) women would not have received hypoglycaemics. If the NICE criteria were applied, 36/54 (66.7%) women would not have received hypoglycaemics. Maternal insulin, HOMA-IR and C-peptide measured at the time of the OGTT showed evidence of increased insulin resistance in women who had GDM based on the WHO criteria but who had a normal OGTT based on the Canadian or NICE criteria. Conclusions: Under stringent research conditions, our study suggests that the Canadian and, in particular, the NICE criteria are not identifying women who may benefit from improved glycaemic control. These findings support the need for the planned review of the NICE guidelines on GDM in 2020.