Download OBJECTIVES - Idaho Perinatal Project

UPDATE ON GESTATIONAL DIABETES:
CONTROVERSIES, CHANGES AND CHALLENGES
JAMES R. SCOTT, MD
I HAVE NO CONFLICT OF INTEREST TO DISCLOSE
OBJECTIVES
• TO DEFINE GESTATIONAL DIABETES,
ITS PREVALENCE AND DIAGNOSIS
• TO RECOGNIZE THE COMPLICATIONS
FOR MOTHER AND BABY
• TO APPLY THE FINDINGS OF THE NIH
CONFERENCE TO YOUR PATIENTS
DEFINITIONS
• TYPE 1 DIABETES (JUVENILE, INSULIN DEPENDENT)
COMPLETE FAILURE OF PANCREAS TO SECRETE
INSULIN
•
TYPE 2 DIABETES (ADULT ONSET)
INSULIN SECRETORY DEFICIENCY & INSULIN
RESISTANCE IN VARIOUS ORGANS
• GESTATIONAL DIABETES (GDM, PRE-DIABETES)
• FIRST RECOGNIZED DURING PREGNANCY
• PREGNANCY HORMONES  CARBOHYDRATE
INTOLERANCE
THE PROBLEM
• DIABETES ASSOCIATED WITH OBESITY
• 1/3rd OF AMERICANS OBESE & INCREASING
• 11% OF ADULT AMERICANS HAVE DIABETES
• 35 % HAVE PREDIABETES
• Total = ALMOST HALF THE POPULATION
• PREVALENCE INCREASING & AT YOUNGER AGE
• GDM COMMON COMPLICATION - 6-7 % OF
PREGNANCIES
• US COST - $635 MILLION ANNUALLY
BOISE
27.9%
22.2 –
34.2
SCREENING TEST FOR GDM DIAGNOSIS
• CRITERIA ESTABLISHED 30-40 YEARS AGO
• TO IDENTIFY WOMEN AT RISK OF
DEVELOPING DIABETES LATER IN LIFE
• 50% DEVELOP DIABETES IN 22-28 YEARS
• BASED ON NON-PREGNANT WOMEN
• NOT TO IDENTIFY RISK OF ADVERSE
PREGNANCY OUTCOME
GDM SCREENING CONTROVERSIES
Universal vs targeted screening debated
• US: Most screen all pregnant women
• US Preventive Health Service does not
recommend screening (2008)
“Current evidence is insufficient to assess the
balance between the benefits and harms of
screening women for GDM either before or after 24
wks. Harms of screening include short-term
anxiety…and inconvenience to women and medical
practices because most positive screening tests are
likely false positives.”
CURRENTLY, ALL PREGNANT WOMEN
TESTED FOR GDM AT 24-28 WEEKS
SOME TEST WOMEN AT HIGH RISK FOR GDM
(AND ALL TYPE 1 DIABETICS SHOULD BE) AT
FIRST PRENATAL VISIT
•
50 GM GLUCOSE SCREEN > 140 mg/dl
•
HbA1C GDM > 6.5
(Has not been validated)
AT RISK FOR GDM
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OLDER THAN AGE 25
OVERWEIGHT
HAD GDM BEFORE
HAD VERY LARGE BABY
CLOSE RELATIVE WITH DIABETES
PREVIOUS STILLBIRTH
AFRICAN AMERICAN, INDIAN, HISPANIC
U.S. GDM SCREENING/DIAGNOSIS
TWO - STEP TESTING
• 1 hr 50 gm oral glucose load @ 24-28 wks
If >140 mg/dl 
• 3 hr 100 gm oral glucose load [> 2 values]
Fasting 105 mg/dl
1 hr
190 mg/dl
2 hr
165 mg/dl
3 hr
145 mg/dl
Distribution of Blood Sugars in Pregnancy
Overt DM
Gestational DM
Blood glucose
GDM COMPLICATIONS
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PREECLAMPSIA
MACROSOMIA
SHOULDER DYSTOCIA, BIRTH INJURY
CESAREAN DELIVERY
NEONATAL
• Hyperbilirubinemia
• Hypoglycemia
• Respiratory Distress Syndrome
PRIOR TO 2005, NO EVIDENCE THAT
TREATMENT OF GDM IMPROVED
MATERNAL OR INFANT OUTCOME
• Macrosomia/LGA
• Shoulder Dystocia
NEW DATA DEMONSTRATED
HYPERGLYCEMIA IS A CONTINUUM
• 2008 HAPO Study: 25,505 women
• Continuous association between glucose
levels and adverse pregnancy outcomes
• Increasing fasting, 1 and 2 hr glucose 
glucose
• Birth weight >90%tile
• No clear cut-point
NEW CRITERIA FOR DIAGNOSING GDM PROPOSED
• Criteria based on pregnancy outcomes
• Cut-offs defined from adverse outcomes
• Most of world uses 2hr 75 gm OGTT
• Endorsed by American Diabetes Association
LOWER THRESHOLDS
• Recommended IADPS thresholds
correspond to 1.75-fold risk for large
and/or “hyperinsulinemic” infants
• 70 – 80% of overgrown infants born
to women without diabetes
Metzger et al NEJM 2008
• SINGLE STEP 75 g 2 hr OGTT - One
abnormal value for GDM diagnosis:
Fasting
92 mg/dl
1 hr
180 mg/dl
2hr
153 mg/dl
• Lowers thresholds  more women
diagnosed as GDM
Increased Prevalence ~ 18%
Overt DM
Gestational DM
New Gestational DM
Blood glucose
MAY BE EVEN HIGHER
• GDM tripled from 10.3% to 30.1%
using IADPSG thresholds.
Reyes-Munoz et al Endocrine Practice 2012
• GDM rate increased to 27.5 %
Bodmer-Roy et al Obstet Gynecol 2012
Rationale for Consensus Conference
• To Address this complicated issue
• To clarify diagnostic thresholds
• Rigorous evaluation of existing evidence
• Implications of new proposed thresholds
• Develop Recommendations
•Produce consensus statements on important,
controversial topics in medicine
•Began in 1977
•Goal: evaluate available scientific information and
develop a statement that advances understanding
of the issue useful to health professionals and the
public at large
http://prevention.nih.gov/cdp/about.aspx
Process:
• Independent systematic review by AHRQ
Evidence-based Practice Center
•Provided to panel 6 wks prior to conference
• Conference
•2.5 days of expert presentations and open public
discussion
•Panel drafts statement for presentation on 3rd day
Consensus Conference Panelists:
•Knowledgeable about topic but have no
published or known opinion on subject
•No financial or career
interest in topic
•Represent a variety of
perspectives
“independent assessment of available knowledge”
CHARGE – EVALUATE EVIDENCE AND
IMPLICATIONS IF NEW GDM SCREENING
PROPOSAL INSTITUTED
1. Evidence that additional patients identified
have increased frequency of maternal/
perinatal morbidities
2. Evidence that these morbidities can be
prevented or decreased by intervention
3. Evidence that benefits outweigh harms
incurred
Potential Benefits
ACCEPTED
• WOULD HAVE UNIFORM WORLDWIDE
SCREENING SYSTEM
• BASED ON PREGNANCY OUTCOMES
• CUT-OFFS BASED ON ADVERSE EVENTS
• ABLE TO COMPARE RESEARCH & CLINICAL
OUTCOMES
HAPO STUDY
• Showed increased maternal and
perinatal risks at thresholds lower
than currently used, but…..
• Maternal BMI and weight gain major
confounders
Metzger et al NEJM 2008
ACHOIS RCT ON Rx vs No Rx
• Reduced preeclampsia from
18% to 12%
• Reduced LGA from 22% to 13%
• Reduced birth wt > 4000 gm
from 21% to 13%
Crowther et al. NEJM 2005
MFM NETWORK RCT ON Rx vs NO Rx
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Reduced LGA from 14.5% to 7.1%
Reduced shoulder dystocia from 18% to 7%
Reduced birth trauma from 1.3% to 0.6%
Reduced neonatal composite score (37 to 32)
No stillbirths in either group
Rate of cesarean same in both groups
Landon et al NEJM 2009
CAUTION IN INTERPRETATION
1. Trial participants highly motivated ? Generalizable to practice
2. Not all treatments were same (not
studied)
3. Different thresholds for criteria to
diagnose GDM
CONCLUSIONS
• GDM Risks present but mild and
relatively low even without Rx
• Maternal Rx reduces some maternal
and infant adverse outcomes
•Overall reduction in adverse events
relatively small
Potential Harms
PROBLEMS IN REAL WORLD
PATIENTS
•MEDICALIZATION OF PREGNANCY
•INCONVENIENCE – MUST SCHEDULE OGTT
(REQUIRES FASTING) FOR ALL OB PATIENTS
•MONITORING OF GLUCOSE
•MORE VISITS, TRAVEL, TIME, BABYSITTERS
•EMOTIONAL IMPACT
IMPLICATIONS FOR PROVIDERS
•MANPOWER – MORE PERSONNEL NEEDED
FOR 30% INCREASED WORKLOAD
• MORE EDUCATION VISITS, CLINIC VISITS,
TESTING VISITS
• MORE ULTRASOUNDS, NSTs AND OTHER
MONITORING
• MORE INDUCTONS
•PROBABLY MORE CESEAREAN DELIVERIES
• HIGHER RATES OF NBICU ADMISSIONS
IMPLICATIONS FOR U.S. HEALTH CARE SYSTEM
• INSTITUTING CHANGE
• SIGNIFICANT IMPACT ON CAPACITY
• DRAMATIC INCREASE IN WOMEN WITH
MILDER GDM DIAGNOSIS WILL LEAD TO
SIGNIFICANT HEALTH CARE COSTS
Annual Cost of Gestational Diabetes
$2 Billion
$636 Million
Status Quo
IADPSG
Chen et al, Population Health Management, 2009
MOST IMPORTANT
• No evidence that identification
and treatment of this new large
group of “Borderline GDM”
women is beneficial
• Improvement in short-term
outcomes in women with mild
GDM less likely
CONCLUSION
• Not sufficient evidence to adopt one-step
approach
• Would increase prevalence of GDM, costs, and
interventions without improvements in most
clinically important patient outcomes
• Given potential benefits of one-step approach,
further research and reconsideration warranted
Panel supports maintaining current
U.S. diagnostic approach for
gestational diabetes mellitus
http://www.nih.gov/news/health/mar2013/o
d-06.htm
http://www.nih.gov/news/health/mar2013/od-06.htm
BOTTOM LINE:
• Disadvantages outweigh advantages
Keep present two-step approach
• Screen with 1 hr OGTT followed by
•
3 hr OGTT prn
MY PERSPECTIVE
• NIH CONFERENCE GOT IT RIGHT
• DON’T OVERDIAGNOSE OR OVERTREAT
GESTATIONAL DIABETES
• OBESITY BIGGER PROBLEM AND DIFFICULT
TO MANAGE
• TYPE 1 DIABETES MUCH MORE SERIOUS
FOR MOTHER AND BABY – NEED EXPERT
CARE AND “WATCH HER LIKE A HAWK”
REFERENCES
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VanDorsten JP, DODSON W, Espeland MA et al. Diagnosing gestational
diabetes mellitus. NIH Consensus Development Conference Statement.
NIH Consens State Sci Statements 2013;29(1):1-30. Available at:
http://prevention.nih.gov/cdp/conference/2013/gdm/files/Gestional_
Diabetes_Mellitus.508.pdf
Gestational Diabetes Mellitus. ACOG Practice Bulletin 2013;137:1-11.
Crowther CA, Hiller JE, Moss JR et al. Effect of treatment of gestational
diabetes mellitus on pregnancy outcomes. Australian Carbohydrate
Intolerance study (ACHOIS) Trial Group. N Engl J Med 2005;352:2477-86
Metzger BE, Lowe LP, Dyer AR et al. Hyperglycemia and adverse
pregnancy outcomes. HAPO Study Cooperative Research Group . N Engl J
Med 2008;358:1991-2002.
Landon MB, Spong CY, Thom E et al. A multicenter, randomized trial of
treatment for mild gestational diabetes. Eunice Kennedy Shriver NICHD
Maternal-Fetal Medicine Units Network. N Engl J Med 2009;361;1339-48
Metzger BE, Gabbe SG, Person B et al. International association of
diabetes and pregnancy study groups recommendations on the diagnosis
and classification of hyperglycemia in pregnancy. International
Association of Diabetes and Pregnancy Study Groups Consensus Panel.
Diabetes Care 2010;33;676-82.