Hypoglycaemia on an oral glucose tolerance test in pregnancy - Is it clinically significant?

Aim: During pregnancy, some women have a low glucose level on the 75 g oral glucose tolerance test (OGTT). The implications of this are unclear and there is no guideline on how to manage these women. Method: We recruited pregnant women with a glucose level <3.5 mmol/L at 1- or 2-h during a screening antenatal OGTT. These women (Group 1) underwent self-monitoring of blood glucose (SMBG) over a two-week period. We also compared Group 1 0 s demographic and pregnancy outcomes data with women who had normal OGTTresults (Group 2) and women diagnosed with gestational diabetes mellitus (GDM) (Group 3). Results: 52 women were recruited. Post-hoc analysis of the SMBG results revealed 50% of women experienced 2 or more elevated fasting BGLs (>5.1 mmol/L) in a week when using the Australian Diabetes in Pregnancy Society (ADIPS) criteria. A further 8% women had elevated 2-h glucose levels (above 6.7 mmol/L). Group 1 women tended to have higher booking weight. They were less likely to have a history of macrosomia or be of East or South-East Asian ethnicity. There were no differences in pregnancy outcomes between Groups 1 and 2, but Group 1 had a higher rate of congenital abnormality (6%) than Group 3 (2%). Conclusion: A large proportion of pregnant women who had a low glucose level on OGTT had elevated glucose levels on SMBG, however their pregnancy outcomes were not significantly different to women who had a normal OGTT. Currently there is not enough evidence to advocate routine SMBG and treatment for this group of women. (C) 2018 Elsevier B.V. All rights reserved.