Oral Presentation ESA-SRB Conference 2015

Gestational diabetes mellitus and adverse pregnancy outcomes: the impact of different treatment targets at two major Australian maternity services. (#101)

Sally Abell 1 2 , Jacqueline Boyle 1 3 , Alison Nankervis 4 , Sanjeeva Ranasinha 1 , Georgia Soldatos 1 2 , Euan Wallace 3 5 , Sophia Zoungas 1 2 , Helena Teede 1 2
  1. Monash Centre for Health Research and Implementation, Monash University, Melbourne
  2. Diabetes and Vascular Medicine Unit, Monash Health, Victoria
  3. Monash Women's Services, Monash Health, Clayton, Victoria
  4. Royal Women's Hospital, Parkville, Victoria
  5. The Ritchie Centre, Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria

Objective
There is insufficient evidence for treatment targets in Gestational Diabetes Mellitus (GDM).  We aimed to explore the impact of different treatment targets on pregnancy outcomes. 

Methods
An observational study was conducted of singleton births >20 weeks at Monash Health (MH) and Royal Women’s Hospital (RWH) from 2009-2013. Data (pregnancy details, maternal and neonatal outcomes) were obtained from each hospital’s pregnancy database. Outcomes for women with GDM at MH (n=2,891) and RWH (n=1,930) were compared [diagnosis: 2hr 75g OGTT at 24-28weeks with fasting glucose ≥5.5mmol/L and/or 2hr ≥8.0mmol/L]. Each hospital follows a similar GDM management protocol but applies different treatment targets: MH fasting <5.5mmol/L, 2hr post-prandial <7.0mmol/L; RWH fasting <5.0mmol/L, 2hr <6.7mmol/L. Descriptive statistics are presented. Multivariable regression analysis will be used to examine associations between GDM treatment and adverse outcomes.

Results
The prevalence of GDM and requirement for insulin at MH were 7.9% and 31%, and at RWH with stricter treatment targets were 6.3% and 47% respectively. Over half of women with GDM were overweight or obese. The rate of special care nursery admission (29.6% vs 17.0%) was higher at MH compared to RWH, but rates of induction of labour (30.6% vs 56.6%) and caesarean section (33.8% vs 39.5%) were lower (all p<0.001), partly reflecting hospital protocols. Babies of women with GDM were born later (mean gestation 39±2 vs 38±2wks, p<0.001) at MH compared to RWH, and had higher rates of respiratory distress (3.6% vs 1.2%, p<0.001), hypoglycaemia (9.9% vs 2.2%, p<0.001) and macrosomia (11.3% vs 9.5%, p=0.035), but lower rates of pre-term birth (8.5% vs 11.3%, p=0.001) and stillbirth (0.3% vs 0.7%, p=0.024). Rates of shoulder dystocia and jaundice were comparable.

Conclusions
Stricter treatment targets for GDM appear to reduce macrosomia, without increasing neonatal hypoglycaemia or special care nursery admission, but may be associated with more obstetric intervention.