GESTATIONAL DIABETES FORUM
28/5/14
Hyperglycemia in Pregnancy
Gestational Diabetes Mellitus
• Is GDM important?
• How should we screen for it?
• Does treatment make a difference?
– What are the treatment options?
Medical Management of GDM
Professor David McIntyre
• Approaching 100% consensus regarding diagnosis
Australian Consensus
• RANZCOG convened consensus conference
Nov 1, 2013
• Present: RANZCOG, ADIPS, RCPA, ADS,
ADEA, ACM, SOMANZ
• Absent: ESA, RACGP
• Major recommendations:
– Cease GCT July 2014
– Adopt IADPSG / WHO criteria Jan 2015
Australian Consensus
• NHMRC guidelines for Antenatal Care
– First visit – assess risk of DM (Age, BMI,
previous GDM, FH diabetes, PCOS, ethnicity)
– Early test for hyperglycemia in women at higher
risk
– Test (or re – test) at 24 – 28 weeks if not known
DM
– Use WHO / IADPSG protocol and thresholds
Finer points
• Exactly who is “high risk”?
• Terminology: “Overt Diabetes” (IADPSG) vs.
“Diabetes in Pregnancy” (WHO) vs. No
specific comment (ADIPS)
• Role of HbA1c
• Remote areas ?
• Intensity of treatment?
Evidence for benefit of GDM treatment
Treatment of GDM Reduces Adverse Outcomes*
Outcome
ACHOIS RCT (%)
P
Not treated
Treated
BW >90th percentile
22
13
BW < 10th centile
7
7
NICU admission
61
71
0.04
Shoulder Dystocia
3
1
0.08
Preeclampsia
18
12
0.02
*Crowther C et al. NEJM 352: 2005
<0.001
Treatment of GDM Reduces Adverse Outcomes*
Outcome
NICHD RCT (%)
P
Not treated
Treated
BW >90th
percentile
14.5
7.1
<0.001
C-peptide >95th
percentile
22.8
17.7
0.07
NICU admission
11.6
9.0
0.19
Shoulder
Dystocia
4.0
1.5
0.02
Preeclampsia
5.5
2.5
0.02
*Landon MB et al. NEJM 361:1339-48, 2009
Formal cost effectiveness
Incremental Cost GDM
Cost / QALY
Conclusions
ACHOIS
$US 247
$US 2,186
Cost effective
MFMNU
$US 456
$US 20,412
Cost effective
Likely cost effective at
lower glucose levels
Study
A7:2007
MS et al AJOG MFMNU: Ohno 282: 2011
GDM - what we might like to see
The dichotomous dilemma
Badness vs. Category
30
25
20
iGDM
15
10
5
Not GDM
GDM
0
1
2
3
4
5
iGDM category
6
7
What we actually see – HAPO AJOG 2010
Hyperglycemia & adverse pregnancy outcome study
Study showed that mild elevations of BGL associated with adverse pregnancy outcomes
Shades of Grey
GDM screening tests: One Step versus Two Step Process with a
Glucose Challenge Test
• GCT lacks both sensitivity and specificity
– Leeuwen BJOG 2012
– Systematic review of all studies with both GCT and OGTT in all women
– Overall sensitivity for GDM diagnosis on OGTT ~0.74
• Issues
–
–
–
–
25 % GDM missed with GCT
Need to return for OGTT if GCT positive
Loss of follow up
Diagnosis and therapy delayed
Van Leeuwen et al. (BJOG 2012;119:393–401)
ADIPS GDM diagnostic criteria - 2013
1. Early testing for GDM with risk factors
1.
2.
“Moderate risk factors” for GDM screened with either a random
or a fasting glucose test followed by a pregnancy OGTT (POGTT)
if clinically indicated
“High risk” of GDM (one high RF or two moderate RF) should
undergo a 75 g POGTT
ADIPS GDM diagnostic criteria - 2013
Moderate Risk factors
• Ethnicity: Asian, Indian
subcontinent, Aboriginal,
Torres Strait Islander, Pacific,
Islander, Maori, Middle
Eastern, non‐white African
• BMI 25 – 35 kg/m2
High Risk factors
•
•
•
•
•
•
•
•
Previous GDM
Previously elevated BGL
Maternal age ≥40 years
Family history DM (1st degree relative
with DM or a sister with GDM)
BMI > 35 kg/m2
Previous macrosomia (baby with birth
weight > 4500 g or > 90th centile)
PCOS
Medications: corticosteroids,
antipsychotics
ADIPS GDM diagnostic criteria - 2013
2. Routine testing for GDM
• All women should have an 75 gm fasting POGTT at 24-28 weeks
• Diagnosis of GDM ( Recommended by RANZCOG to be adopted by
Jan 2015)
– one or more of the following glucose levels are elevated;
• Fasting glucose ≥ 5.1mmol/L
• 1‐hr glucose ≥ 10.0mmol/L
• 2‐hr glucose ≥ 8.5mmol/L
IADPSG vs. 1991
‘Ad hoc’ / ADIPS
Measure
Fasting VPG
1 hr VPG
2 hr VPG
Value (mmol/L) ADIPS (mmol/L)
≥ 5.1
5.5
≥ 10.0
≥ 8.5
N/A
8.0
Tsunami of GDM?
Australian Data - Population
• Compared to ADIPS criteria, using 1275 women
from Wollongong
Measure
Public GDM
Private GDM
Overall GDM
% Abnormal
IADPSG
9.1
% Abnormal
ADIPS
8.6
16.2
13.0
10.5
9.6
Moses R et al MJA 2011: 194
Contemporary MMH cohort (n=2017)
GDM
by Criteria
Normal
IADPSG Only
Ad hoc Only
Both
2%
6%
3%
89%
GDM ; Management - Multidisciplinary
•
•
•
•
•
Dietician & Diabetes educator review
Home Blood glucose monitoring – qid, fasting and 2 hour post prandial
Lifestyle changes – diet and physical activity
AN care continued in collaboration with midwives/obstetricians
BGL Targets - little firm evidence regarding BG targets
Current
targets
•
- Fasting <5.5mmol/L
- 1hr post prandial <8.0 mmol/L
- 2 hr post prandial <7 mmol/L
(<5.1 mmol/L)
(< 7.4 mml/L)
(<6.7 mmol/L)
Suggested BG treatment targets
based on 2SDs above the mean
values for pregnant women
without known risk factors.
Treatment options Insulin or metformin ( in some centres) if failing to meet glucose
targets
Individualize Rx - fetal growth!
Glycemia in normal pregnancy (gestational week 33.8 ± 2.3) across
11 studies published between 1975 and 2008.
Mean + 1 SD:
Fasting 4.4 mmol/L
1 hour 6.8 mmol/L
2 hour 6.1 mmol/L
Mean + 2 SD:
Fasting 4.8 mmol/L
1 hour 7.5 mmol/L
2 hour 6.6 mmol/L
Hernandez T L et al. Dia Care 2011;34:1660-1668
Copyright © 2011 American Diabetes Association, Inc.
Recommended targets
Fasting
mmol/L
1 hour PP
mmol/L
2 hours PP
mmol/L
Old ADIPS
5.5
8.0
7.0
New ADIPS
5.0
7.4
6.7
USA
5.3
Mean + 1 SD*
4.4
6.8
6.1
Mean + 2 SD*
4.8
7.5
6.6
* from:- Hernandez et al D Care, 2011
6.7
Medication use
• “Lifestyle” for all
• ? Availability of extra resources (e.g.
dieticians / diabetes educators / exercise
physiologists)
• Medication use
– ACHOIS 20%, US MFMNU trial 10% (insulin)
– MMH clinic 35 – 40 % (insulin + metformin)
• Accuracy of home glucose meters in the
GDM range
Models of care
•
•
•
•
•
•
Variable around Australia
Groups vs. Individual
RCT models of care vs. resources and reality
Fetal monitoring
GP based care
Risk stratification
Supporting clinical care
•
•
•
•
Use of IT – meters / decision support tools
Telehealth to support isolated areas
Educational packages
Structure for post natal / inter pregnancy
care
– Link to mother and baby health checks
Metformin vs. Insulin
• Women entitled to explanation and choice
of therapy
• Immediate pregnancy outcomes with
metformin comparable to insulin therapy
• No suggestion teratogenicity
• Convenience of treatment
• Longer term outcomes for children.
Metformin vs. Insulin
• Metformin
– Not quite as easy as it seems
– GIT side effects may be troublesome
– Officially “Category C” in Australia
– Risk of “dumbing down” of high risk pregnancy
care
– Push to use metformin economic rather than
clinical
Postnatal care of women with GDM
• Recommendations:
– 75 gr 2 hr OGTT 6-12 weeks postpartum to exclude diabetes
– Follow up OGTT two yearly (possibly at time of cervical screening)
or yearly if planning another pregnancy
– Repeat OGTT early in subsequent pregnancy
– Lower risk women consider fasting PG every 1-2 years
– Follow up of impaired fasting glucose by regular checks for frank
diabetes in addition to assessment of other risk factors of
macrovascular disease
Other important issues
• Long term maternal health and opportunities for
prevention
– Risk of diabetes – 70 % lifetime risk of
developing T2 DM
– Risk of cardiovascular disease
• Long term health of children – increased risk
Obesity and IGT
• Intergenerational transmission of diabetes and
other risks
Heaven / Nirvana of Diabetes Prevention
Population / Environment measures
Pre conception testing
Higher risk
Early pregnancy testing
Higher risk
“Standard” GDM testing
Higher risk
Repercussions
PERSONAL – Where we draw the line does matter
Non - GDM
Pregnancy
Maternal Health
Baby Health
GDM
Pregnancy
Maternal Health
Baby Health