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* * Crowther C et al. NEJM 352: 2005

Treatment of GDM Reduces Adverse Outcomes * * Landon MB et al. NEJM 361: , 2009

Formal cost effectiveness A7:2007 MS et al AJOG MFMNU: Ohno 282: 2011

GDM - what we might like to see The dichotomous dilemma GDM Not GDM

What we actually see – HAPO AJOG 2010 Hyperglycemia & adverse pregnancy outcome study S tudy 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 Early testing for GDM with risk factors  “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 Moderate Risk factorsHigh Risk factors Ethnicity: Asian, Indian subcontinent, Aboriginal, Torres Strait Islander, Pacific, Islander, Maori, Middle Eastern, non ‐ white African BMI 25 – 35 kg/m2 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 Routine testing for GDM All women should have an 75 gm fasting POGTT at 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 ‘Ad hoc’ / ADIPS

Tsunami of GDM? Australian Data - Population Compared to ADIPS criteria, using 1275 women from Wollongong Moses R et al MJA 2011: 194

Contemporary MMH cohort (n = 2017)

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 - Fasting <5.5mmol/L (<5.1 mmol/L) - 1hr post prandial <8.0 mmol/L(< 7.4 mml/L) - 2 hr post prandial <7 mmol/L(<6.7 mmol/L) Treatment options Insulin or metformin ( in some centres) if failing to meet glucose targets Suggested BG treatment targets based on 2SDs above the mean values for pregnant women without known risk factors. Current targets

Individualize Rx - fetal growth!

Glycemia in normal pregnancy (gestational week 33.8 ± 2.3) across 11 studies published between 1975 and Hernandez T L et al. Dia Care 2011;34: Copyright © 2011 American Diabetes Association, Inc. 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

Recommended targets Fasting mmol/L 1 hour PP mmol/L 2 hours PP mmol/L Old ADIPS New ADIPS USA Mean + 1 SD* Mean + 2 SD* * from:- Hernandez et al D Care, 2011

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 Early pregnancy testing “ Standard” GDM testing Pre conception testingHigher risk

Repercussions PERSONAL – Where we draw the line does matter GDM  Pregnancy  Maternal Health  Baby Health Non - GDM  Pregnancy  Maternal Health  Baby Health