Oral Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2024

Glucose stabilisation using fluoride citrate tubes for OGTT improves identification of Aboriginal women requiring pharmaceutical intervention for GDM (107627)

Erica P Spry 1 , Emma L Jamieson 2 , Lorraine Anderson 3 , Mark A Hoey 2 , Andrew B Kirke 2 , David N Atkinson 4 , Julia V Marley 4
  1. Kimberley Aboriginal Medical Services and Rural Clinical School of Western Australia, University of Western Australia, Broome, WA, Australia
  2. Rural Clinical School of Western Australia, Bunbury, WA, The University of Western Australia, Bunbury, WA, Australia
  3. Kimberley Aboriginal Medical Services, Broome, Western Australia, Australia
  4. Rural Clinical School of Western Australia, Broome, The University of Western Australia, Broome, WA, Australia

Background: An estimated 62% of GDM cases in rural and remote Australia are missed due to glucose instability in fluoride-oxalate (FLOX) samples. In September 2019, Kimberley Aboriginal Community Control Health Services (ACCHS) implemented fluoride-citrate (FC) tubes to immediately stabilise OGTT samples.

Aim: To describe implementation of FC tubes and evaluate the impact on detection and management of GDM.

Methods: Retrospective audit of antenatal records for women attending a Kimberley ACCHS (2018-2021) to describe maternal characteristics, OGTT outcomes (≥24-weeks gestation), GDM management, and birth outcomes, pre- and post-FC tube implementation (T1 and T2 audit periods respectively). Semi-structured interviews with primary and secondary healthcare clinicians, analysed using direct qualitative content analysis.

Results: Of 988 women eligible for an OGTT ≥24-weeks gestation, 563 (57%) did not have a record of an OGTT and only 359 (36.3%) completed an OGTT within the audit period: 198 T1 (FLOX); 161 T2 (FC). Plasma glucose at all three OGTT time-points was 0.8 to 0.9 mmol/L higher in the T2 audit period (v T1). The 2.7-fold increase in GDM diagnoses with FC tubes was largely due to increased detection at the fasting sample (39.3% v 76.7% of GDM cases, P = 0.001) and 6-fold more women were recommended for pharmaceutical management of hyperglycaemia (2.5% v 14.9%, P <0.001). Neonatal birth weight and growth-for-gestational-age outcomes were similar between the T1 and T2 audit periods (3194 g ± 557 v 3229 g ± 537, P = 0.558; LGA: 10.8% v 15.2%, P = 0.223; SGA: 13.9% v 15.9%, P = 0.608). However, induction of labour was significantly higher in the T2 period (39.3% v 50.0%, P = 0.047), with GDM more commonly cited as the reason for induction (2.9% v 23.3%, P <0.0001).

Initial clinician feedback related to increased burden of GDM and associated concerns of low resources and increased intervention at birth. Overtime clinicians become more confident in the glucose measurements using FC tubes and reported the need for specific recommendations for interpretation of borderline results and the importance for interpretation of results as part of a complete clinical picture.

Discussion: Implementation of FC tubes significantly increased GDM diagnosis and pharmaceutical intervention and induction of labour increased concurrently. There was increased clinician awareness of GDM and concern about missed GDM diagnoses with FLOX tubes. Larger cohorts are required to evaluate whether improved detection and management of GDM translate to improved birth outcomes.