Background:

Recent changes to the diagnosis and management of gestational diabetes (GDM) has led to an increase in the number of women being diagnosed with and treated for GDM as well as tighter glycaemic targets. However, the effect of these changes on pregnancy outcomes has not been systematically tested.

Methods:

Outcomes from all women with GDM attending a tertiary antenatal clinic between September 2011 and August 2013 were analysed retrospectively. An interim analysis of 438 women is presented here. Women in the ‘’before guideline change” cohort (BGC) were diagnosed with GDM using the previous diagnostic criteria (FPG ≥ 5.5mmol/L or 2-hr PG ≥ 8.0mmol/L) and blood glucose level (BGL) treatment targets were FPG ≤ 5.5mmol/L and 2-hr post-prandial ≤ 7.0mmol/L. Women in the “after guideline change” cohort (AGC) were diagnosed with GDM using the new diagnostic criteria (FPG ≥ 5.1mmol/L or 1-hr PG ≥ 10.0mmol/L or 2-hr PG ≥ 8.5mmol/L) and BGL treatment targets were FPG ≤ 5.0mmol/L and 2-hr post-prandial ≤ 6.7mmol/L

Results:

There were no significant differences in baseline characteristics between the two groups apart from maternal weight (BGC 73.9kg vs. AGC 82.5kg; p<0.0001) and BMI (BGC 29.2kg/m² vs. AGC 30.82kg/m²; p=0.02). Insulin use was higher in the AGC group (39.9% vs. 25.6%; p=0.002). Neonatal hypoglycaemia <2.6mmol/L (20.1% vs. 27.6%; p=0.07) and shoulder dystocia (4% vs. 7.9%; p=0.08) were lower in the AGC group compared to BGC group. All other maternal and foetal outcomes were comparable between the two groups.

Conclusion:

Our interim analysis demonstrates a trend towards a reduction in neonatal hypoglycaemia and shoulder dystocia with the use of new diagnostic criteria and BGL treatment targets for GDM. We aim to have full data (n=1064) available for the 2016 ADS-ADEA ASM.