new diagnostic criteria for gdm & implications

New Diagnostic Criteria for GDM & Implications

Daniel LW Chan Department of Obstetrics & Gynaecology,

United Christian Hospital (clw042@ha.org.hk)

22 May 2016

Annual Scientific Meeting of O&G Society of HK

Outline

• What has happened?

• What is happening?

• What will (may) happen?

What has happened?

N=148

EDUCATION & AWARENESS

HAPO New Engl J Med 2008

A continuum

IADPSG

Based on the HAPO study

aOR 1.5 aOR 1.75 aOR 2.0

Fasting 5.0 5.1 5.3

1-hour 9.3 10.0 10.6

2-hour 7.9 8.5 9.0

IADPSG consensus

aOR: adjusted Odds Ratio for selected adverse pregnancy outcome

No more “IGT”

>=1

>=2

>=2

>=1

• The GDG considered that the method proposed by IADPSG was appropriate & rather than further complicate the current situation by proposing another new set of criteria, it was advisable to adopt the same methodology for setting diagnostic cut-points

• Decided to accept the general principles behind how these new criteria were derived, in the interest of moving towards a universal standard recommendation for the diagnosis of GDM

Lower cut-off same as IADPSG consensus

No published cohort / intervention studies which compared the IADSPG criteria to the prev. WHO criteria

Cut-off

75g OGTT GDM DM in pregnancy

Fasting 5.1 - 6.9 >=7.0

1 hr >=10

2 hr 8.5 - 11.0 >=11.1

What is happening?

aOR 1.75 – 2.0 vs

aOR 2.0 vs

Retrospective Both groups untreated. No significant differences in maternal characteristics between GDM-1 & GDM-2

N=771 N=1121 N=7943

• A greater no. and proportion of adverse outcomes occurred among women at the higher end (aOR 2.0) of the IADPSG GDM glucose spectrum than at the lower end (aOR 1.75)

• Whether treating women in either / both groups would have resulted in a reduction in frequency of these outcomes is not known

• The use of aOR of 2.0 instead of 1.75 would reduce the % of GDM from 17.8% to 10.5%

WHO Diagnostic Criteria and Classification of Hyperglycaemia First Detected in Pregnancy 2013

McIntyre Best Pract Res Clin Obstet Gynaecol 2015

FIGO EAPM

• Glycemic dysregulation exists on a continuum, decision to pick a single binary threshold requires balancing the harms & benefits

• HAPO study, an observational study, was not designed to determine the benefits of intervention

• No available cost-effective analyses to examine the balance of achieved benefits vs increased costs

ADA rationale of re-introducing the old “2-step”

approach

• The lack of clinical trial interventions demonstrating the benefits of the “one-step” strategy (IADPSG)

• The potential –ve consequences of identifying a large new group of women with GDM

• Screening with a 50-g glucose load test does not require fasting & is therefore easier to accomplish

Meek Diabetologia 2015

Alternative strategies currently used

Booking / 1st T If negative, @ 24-28wk

China FPG >=5.6: GDM FPG >7.0: DM in pregnancy (all)

75g OGTT // FPG: 4.5 – 5.0: for OGTT; > 5.1: GDM

Indian subcontinent 75g OGTT - fasting / nonfasting 2hr value: 7.8-11.0: GDM (all)

Repeat

Latin America Same as China 75g OGTT – 2 hr: >7.8: GDM

UK 75g OGTT – 5.6 / 7.8: GDM (high risk group)

Repeat

What will happen?

Research

WHO Diagnostic Criteria and Classification of Hyperglycaemia First Detected in Pregnancy 2013

Number of publications “Gestational diabetes”

HAPO

IADPSG

WHO

FIGO

• HKCOG guideline

• HA COC working group

Summary

• What has happened? – HAPO -> IADPSG -> WHO -> FIGO

• What is happening? – Impact

• Increase prevalence

– Worldwide response • Increase in adoption of the IADPSG

• Yet, reservations exist

• What will (may) happen? – Research

– Discussion

New Diagnostic Criteria for GDM & Implications

Daniel LW Chan Department of Obstetrics & Gynaecology,

United Christian Hospital (clw042@ha.org.hk)

22 May 2016

Annual Scientific Meeting of O&G Society of HK