Oral Presentation Australian Diabetes in Pregnancy Society 2018

Impact of new criteria for the diagnosis of gestational diabetes A maternal and neonatal health outcome and economic analysis in a large tertiary level maternity centre (#8)

Thomas J Cade 1 , Shaun Brennecke 1 , Alexander Polyakov 1
  1. Royal Women's Hospital, Fitzroy, VIC, Australia

Aim: To compare a cohort diagnosed with gestational diabetes under 1998 ADIPS criteria with 2014 ADIPS criteria, specifically to assess any improvements in outcomes, to attribute costs to the increased incidence and to assess any overall economic benefit.


Methods: Women diagnosed with gestational diabetes in 2014 and in 2016 were included as cases. Control groups in each year were those who did not have GDM (pre-existing diabetes and multiple pregnancy were exclusion criteria). Three analyses were undertaken. Firstly, all women in 2014 were compared to all women in 2016. Secondly, women with GDM were compared to controls in each year. Finally, women with GDM in 2014 were compared to women with GDM in 2016. Analyses included sub-division for diet-controlled and insulin-requiring GDM. Models of care for routine pregnancy, GDM diet-controlled and GDM-insulin controlled were costed using average-occasions-of-service for clinical reviews, pharmacy fees for medications and consumables, and Medicare Benefits Schedule item numbers for ultrasound services.


Results: There was an increase in annual incidence for GDM from 6.0% to 10.4% with costs of care increasing by over $900 000  (gross) and $560 000 (nett). There was a small hospital-wide reduction in very large babies (>95%) with no other significant differences. Women with GDM remain a higher risk cohort than those without GDM, but in 2016 women with GDM (diet-controlled) have similar outcomes to women without GDM.


Conclusions: The new criteria for diagnosing GDM has resulted in a marked increase in annual incidence (73% relative, 4.4% absolute) without a significant improvement in maternal and neonatal outcomes and with a concomitant increase in costs of care. The new criteria may lead to long-term improvements in health that are cost-effective but further research is required to substantiate this. Future randomized controlled trials into different systems of diagnosis and less expensive models of care are also warranted.