Oral Presentation Australasian Diabetes in Pregnancy Society Conference 2026

Proactive insulin initiation for antenatal betamethasone-induced hyperglycaemia in women with diabetes in pregnancy: a prospective cohort study (140471)

Annabel Jones 1 2 , I-Lynn Lee 1 2 , Devaang Kevat 1 2 , Shane Hamblin 1 2 3 , Christopher Yates 1 2
  1. Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
  2. Endocrinology and Diabetes, Western Health, Melbourne, Victoria, Australia
  3. School of Public Health and Preventative Medicine, Monash University, Melbourne, VIC, Australia

Background/Aim: In patients with pre-gestational or gestational diabetes, antenatal glucocorticoids induce significant hyperglycaemia for up to 72 hrs. Management of maternal hyperglycaemia is important to reduce adverse consequences including neonatal hypoglycaemia, however there are no validated protocols and institutional practice varies widely. A prospective study conducted previously at our centre demonstrated that a proactive increase in insulin by 50% was insufficient to mitigate maternal hyperglycaemia, with only 35.3% of readings in target range. We sought to investigate the safety and utility of an intensified protocol to manage maternal dysglycaemia using continuous glucose monitoring.

Methods: A prospective cohort study was undertaken including 40 women with pre-gestational diabetes or gestational diabetes managed with insulin receiving antenatal betamethasone to investigate the utility and safety of a proactive subcutaneous insulin protocol from time 0-72 hours post first dose betamethasone to achieve time in target range (3.5-7.8mmol/L). Glycaemia was evaluated at a pre-specified end point of 15 participants, and the protocol was subsequently intensified for subsequent participants. Capillary glucose monitoring was utilised in the initial group and continuous glucose monitoring was utilised in the intensified group. Planned insulin increment was 60% in the initial group and 75% in the intensified group.

Results: Interim analysis has been undertaken for 36/40 participants with the full data set to be presented at the conference. 36 women (12 with T2DM, 24 with GDM) were included with median (IQR) gestation 32+3 (30-34+1-5) weeks at first dose betamethasone. In the initial group proportion of time in range was 70% (29.6% above range, 0.4% below range) and in the intensified group with continuous glucose monitoring, time in range was 75.4% (23.8% time above range, 0.8% below range). On day 1,2,3 post first dose betamethasone, median insulin increment was 40%,70% and 43% in the initial group and 89%, 125% and 109% in the intensified group.

Conclusions: Significant maternal hyperglycaemia, best detected with continuous glucose monitoring, occurs following first dose betamethasone in patients with diabetes managed with insulin. Proactive insulin increment above current guideline recommendations reduces dysglycaemia without causing significant maternal hypoglycaemia. Further validation of proactive insulin protocols is required.