ObjectivesThe oral glucose tolerance test (OGTT) is a cumbersome test that is time consuming, labour intensive and often poorly tolerated by pregnant women. To date, glycosylated haemoglobin (HbA1c) is the most accepted measure of chronic glycaemia outside of pregnancy. HbA1c is an uncomplicated test, less time consuming, does not require any specific patient preparation and is considered straightforward compared with the OGTT. Therefore, we prospectively tested the utility of the HbA1c when used as a screening tool in pregnancy for gestational diabetes mellitus (GDM).SettingsPrimary health care. Single tertiary referral centre, Tasmania, Australia.ParticipantsA direct comparison between HbA1c levels and the OGTT results in pregnant women, tested concurrently at the 24–28 gestational week, was undertaken. A full profile of 480 pregnant women during the period from September 2012 to July 2014 was completed. Median and mean age of participants was 29 years (range 18–47 years).InterventionsA simultaneous prospective assessment of HbA1c versus standard OGTT in a cohort of consecutive pregnant women presenting to our institute was performed.ResultsThe number of women who had GDM according to OGTT criteria was 57, representing 11.9% of the evaluated 480 pregnant women. Using a cut-off value for HbA1c at 5.1% (32 mmol/mol) for detecting GDM showed sensitivity of 61% and specificity of 68% with negative predictive value (NPV) of 93%, versus sensitivity of 27% and specificity of 95% with NPV of 91% when using HbA1c cut-off value of 5.4% (36 mmol/mol).ConclusionsOur results suggest that pregnant women with an HbA1c of≥5.4% (36 mmol/mol) should proceed with an OGTT. This may result in a significant reduction in the burden of testing on both patients and testing facility staff and resources. Further investigations are required to integrate and optimise the HbA1c as a single, non-fasting, screening tool for GDM.Trial registration numberACTRN12611000739910.

In women with GDM, fasting glucose on OGTT predicted response to metformin: at fasting glucose ≤5.2 mmol/L, the probability of response was 93%. Antenatal clinics should determine locally relevant predictors of response to metformin in women with GDM.

Introduction Gestational diabetes mellitus (GDM) complicates ∼16% of pregnancies in Australia and has significant implications for health of both mother and baby. Antenatal anxiety and depression are also associated with adverse pregnancy outcomes. The interaction between GDM and mental health in pregnancy is poorly understood. With the aim of exploring the nuanced interaction between GDM and mental health further, we investigated whether GDM treatment modality (diet versus insulin) influenced psychological wellbeing in women with GDM. Methods Psychological wellbeing was assessed in women with GDM treated with diet (GDM-Diet, n = 20) or insulin (GDM-Insulin, n = 15) and pregnant women without GDM (non-GDM, n = 20) using questionnaires [Edinburgh Depression Scale (EDS), State-Trait Anxiety Inventory (STAI-6), and in women with GDM, Problem Areas in Diabetes (PAID)] at 24–34 weeks gestation and again at ∼36 weeks gestation. Results Women in the GDM-insulin group had significantly higher levels of anxiety than the non-GDM group at both time points. Women in the GDM-Diet group had higher levels of anxiety at 24–34 weeks gestation than the non-GDM group but did not differ at ∼36 weeks gestation. Although depression scores tended to be higher in GDM-Insulin and GDM-Diet groups than in the non-GDM group at both time points, this was not statistically significant. Diabetes-related distress was similar in the GDM-Diet and GDM-Insulin groups at both time points and did not change during pregnancy. A high proportion of the GDM-Insulin group had past/current mental illness (60%). Conclusions In this pilot study GDM was associated with differences in psychological wellbeing, specifically increased anxiety in women treated with insulin. Specialised interventions to support women with GDM should be considered, especially those requiring insulin. Trial registration: Not applicable as this was a purely observational study.