Recent Advances in the Diagnosis and Treatment of Gestational Diabetes

1. Recent Advances in the
Diagnosis &
Treatment of Gestational
Diabetes
Chukwuma I. Onyeije, M.D.
gdmdietplan.com

2. Gestational Diabetes remains a
CONTROVERSIAL diagnosis
in perinatal medicine

3. WHAT IS DIABETES?
• Defect in energy regulation
• Defect in energy utilization
• Causes:
– Insulin deficiency
– Insulin resistance
• End result: Elevated blood sugar
• Impact of elevated blood sugar:
– Pregnancy complications
– Multi-organ dysfunction
– Excess mortality

4. 6 -7 percent of pregnancies
are complicated by
GDM

5.  GDM is more common in certain ethnic
groups
 These women also have an increased risk
of developing type 2 diabetes.
At risk groups:
Hispanic, African, Native American, Asian,
Pacific Islands.

6. 60% of Latina women with GDM will
develop type 2 DM.
This level of risk may actually
be manifest by 5 years after the GDM index
pregnancy.

7. Classification of Diabetes
Adapted from The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes
Care. 1997;20:1183-1197.
Type 1
b-cell destruction with lack
of insulin
Type 2
Insulin resistance and
relative insulin deficiency
Gestational Insulin resistance with b-
cell dysfunction
Other types
Genetic defects in b-cell
function,
Pancreatic disease,
Endocrinopathies,
Drug- or chemical- induced,
and other rare forms

8. INSULIN PHYSIOLOGY:
REGULATION OF BLOOD SUGAR

9. TYPE 1 DIABETES: INSULIN DEFICIENCY
-cell destruction
with lack of insulin

10. TYPE 2 DIABETES: INSULIN RESISTANCE
Insulin Resistance

11. GESTATIONAL DIABETES:
INSULIN DEFICIENCY AND INSULIN RESISTANCE
Insulin Resistance
Insulin Deficiency

12. Traditionally, we relied on
risk factors to select
patients most likely
to develop GDM.

13. TRADITIONAL RISK FACTORS:
Family history of diabetes
Previous unexplained stillbirth
Previous large infant
Obesity
Hypertension
Glycosuria
Maternal age older than 25

14. However,
More than half of all women
with GDM lack traditional risk factors
But,
it is NOT cost effective to screen women at
LOW risk for GDM.

15. Who is at LOW risk for GDM?
Low prevalence ethnic group
No known diabetes in first-degree relatives
Younger than 25 years
Normal weight before pregnancy
No history of abnormal glucose metabolism
No history of poor obstetric outcome

16. LOW risk women
represent only 10% of
pregnant population.
Identification of LOW risk women adds
complexity to screening process.

17. THRESHOLD PATIENTS
SCREENING
POSITIVE
SENSITIVITY
140 14-18% 80%
130 20-25% 90%
SCREENING THRESHOLDS FOR GESTATIONAL
DIABETES MELLITUS WITH THE 50-g
ORALGLUCOSE-CHALLENGE TEST

18. Diagnosis of Gestational Diabetes
Three Hour 100 gm glucose tolerance test (GTT)
 Not necessary if GCT is >200mg/dl on screening
 Two abnormal values required for the diagnosis of
gestational diabetes
 Currently two diagnostic criteria acceptable

19. Competing Criteria
NDDG, 1979
•FBS 105
•1 hour 190
•2 hour 165
•3 hour 145
Carpentar and
Coustan, 1982
FBS 95
1 hour 180
2 hour 155
3 hour 140

20. 1990
2000
1997-1998
No Data Less than 4% 4% to 6% Above 6%
Diabetes Trends Among
Adults in the U.S.
Source: CDC, Behavioral Risk Factor Surveillance System.

21. Pathophysiology

22. PRINCIPLE DANGERS
GESTATIONAL DIABETES:
Fetal hyperinsulinemia
PREGESTATIONAL DIABETES:
Fetal Anomalies

23. Normal Glucose Regulation in
Pregnancy
• The pregnant patient has a tendency to develop
HYPOGLYCEMIA between meals
– Related to fetal demand
• Placental steroids cause increased tissue insulin
resistance
– They are “DIABETOGENIC”
• Insulin production INCREASES in normal pregnancy
– By 30%

24. RECALL:
PATHOLOGIC CHANGES IN GDM
Insulin Resistance
Insulin Deficiency

25. Effects of Hyperglycemia in GDM

26. Fetal Hyperinsulinemia
Promotes storage of
excess nutrients
Net Effect: Macrosomia

27. Fetal Hyperinsulinemia
Catabolic effect on excess nutrients
Increased energy usage
Net Effect: Decreased fetal
oxygen storage and episodic
fetal hypoxia

28. Fetal Hyperinsulinemia
• Episodic fetal hypoxia leads to increased catecholamines causing:
– Fetal hypertension
– Cardiac remodelling and hypertrophy
– Increased erythropoietin, RBC’s, hematocrit
– Poor fetal circulation and hyperbilirubinemia
– Stillbirth (?)

29. The Impact of Fetal Macrosomnia
• Increased hyperbilirubinemia
• Increased hypoglycemia
• Increased acidosis
• Increased birth trauma
• Macrosomic children are more likely to develop
glucose intolerance in adulthood

30. Congenital Anomalies and Diabetic Control
Risk for Congenital Anomalies at various levels of Hemoglobin
A1C
Critical periods - 3-6 weeks post conception
Importance of pre-conceptional metabolic care
2.5%
14.0%
23.0%
25.0%
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
< 7.2
7.2 to 9.0
9.2 to 11.1
> 11.2

31. CARE FOR THE PATIENT
WITH DIABETES

32. Pre-Pregnancy Management
• Preconceptional care
– PRECONCEPTION CARE BEGINS AT THE END OF A PREGNANCY
WITH GDM
– Tight glucose control (HbA1c)
– Assessment and treatment of associated medical problems
- Hypertension,
- Renal disease,
- Retinal disease
- Heart disease
– Folic acid
– Assessment of family, financial and personal resources to help
achieve a successful pregnancy

33. FIRST PERINATAL VISIT
or UPON HOSPITALIZATION
• Review routine prenatal lab tests
• Baseline 24 hour urinalysis for protein and creatinine
clearance
• Baseline retinal exam - for Type 1 Diabetics
• EKG - for Type 1 Diabetics
• Thyroid function tests - for Type 1 Diabetics
• Hemoglobin A1C
• Fetal echocardiogram for pregestational diabetics

34. Antepartum Gestational Diabetes Care
• Dietary advice
• Glucose monitoring (5 times per day)
• Insulin therapy if necessary
– Oral Hypoglycemic agents
• Frequent visits to monitor glucose control
• Ultrasound monitoring of fetal growth
• Mode of Delivery:
– Based on obstetric issues
• Timing of Delivery:
– Based on glucose control

35. What is an ADA diet?
•Avoidance of large meals with high
percentage of simple carbohydrates
•Three small meals with three snacks are
preferred
•Low glycemic index foods release calories
from the gut slowly and improve metabolic
control

36. What is an ADA diet?
• Caloric content:
– 35 calories/Kg Ideal body weight (or 15
calories/pound IBW)
– No less than 1800 calories and no more than 2800 calories
– “Eyeball Technique”
- Small patient 1800 calories
- Medium patient 2200 calories
- Large patient 2400 calorie

37. What is a “Low” Glycemic Index
• Glycemic Index (GI):
• Compares equal quantities of
carbohydrate in foods
• Is a measure of the effect on
blood glucose levels over a 2 hr
period
• Provides a measure of
carbohydrate quality.
• Expressed as a percentage
Time
GI = 30
GI = 100
BGLBGL

38. ‘Traditional’ starchy foods have a lower GI
• Barley
• Legumes/beans
• Multigrain ‘Specialty’ breads
• Mueslix
• Porridge oats
33
30’s
40’s
50’s
50’s
Foster-Powell K, Holt SHA, and Brand-Miller JC. International table of glycemic index and glycemic load values:2002. Am
J Clin Nutr. 2002; 76 (1): 5-56.

39. “Sugary” foods have a intermediate-low GI
• Soft drinks
• Flavoured milk (low fat)
• Yogurt (sweetened)
• Ice cream (low fat)
60’s
34
30-40
50’s
Foster-Powell K, Holt SHA, and Brand-Miller JC. International table of glycemic index and glycemic load values:2002. Am
J Clin Nutr. 2002; 76 (1): 5-56.

40. Modern starchy foods have a high GI
• Potatoes
• Cornflakes
• Rice crispies
• Wholegrain bread
• Crackers
• Rice (most types)
85
77
85
70
81
83
Foster-Powell K, Holt SHA, and Brand-Miller JC. International table of glycemic index and glycemic load values:2002. Am
J Clin Nutr. 2002; 76 (1): 5-56.

41. HOME GLUCOSE MONITORING
• Fasting and 2 hour post-
prandial
• Pre-meal values only if
sliding scale short acting
insulin coverage is used
• Early AM value if
hypoglycemia suspected
• Assure that glucose meter is
calibrated

42. INDICATIONS FOR HOSPITALIZATION
• Persistent nausea and vomiting
• Significant maternal infection
• DKA
• Poor control/compliance
• Preterm labor

43. Intensive Inpatient Management:
The APA Hybrid Protocol
• For poorly controlled diabetic patients admitted for
rapid control.
• Empiric insulin with the patient’s current standing
dose:
• Targets adequate glycemic control
– Fasting values: Less than 100 mg/dl
– 2 hour postparandial values: Less than 120 mg/dl
– Avoidance of hypoglycemia, ketonuria, and
hyperglycemia

44. Intensive Inpatient Management:
The APA Hybrid Protocol
• Begin 2200 to 2400 calorie ADA diet.
• Obtain fingerstick every 2 hours for 12-24
hours
• Administer HUMALOG INSULIN for sliding
scale
• Retake blood sugar at 2 hours after EACH
sliding dose noted below and repeat sliding
scale dose of insulin based on FSG.
• Adjust Insulin after 24 hours

45. Intensive Inpatient Management:
The APA Hybrid Protocol
Blood sugar value Administer the
following dosage of
humalog insulin
Recheck Blood sugar
< 140 Hold Humalog insulin 4-6 hours
140-1600 4 Units 2 hours
161-180 6 Units 2 hours
180-200 10 Units 2 hours
200-220 12 Units 2 hours
220-260 14 Units 2 hours
>260 16 Units 2 hours

46. 7/08 11/17/08 11/17/08 11/17/08 11/18/08
Column B
Column C
Patient CH – Before Hybrid Approach
200
300
Chart Title
Patient CH – After Hybrid Approach

47. Intrapartum management
• ABSOLUTE REQUIREMENTS:
– Dextrose containing intravenous fluids
– Insulin
• Hourly glucose monitoring
• Continuous fetal heart rate monitoring
• Continuous tocodynametry
• Manage labor as normal

48. THE APA INSULIN DRIP PROTOCOL
INTRAVENOUS FLUID MAINLINE: D5W @ 125 cc/hr
INSULIN DRIP:
Initially Check Fingerstick every hour
MIX 100 Units Regular insulin in 500 cc NS (0.2 U/cc)
TITRATE INFUSION AS FOLLOWS:
Fingerstick Value Drip Rate Units per hour
FS= <80 Turn off drip 0 U/hr
FS= 80-100 2.5 cc/hr 0.5 U/hr
FS=101-140 5.0 cc/hr 1.0 U/hr
FS= 141-180 7.5 cc/hr 1.5 U/hr
FS= 181-220 10 cc/hr* 2.0 U/hr
FS> 220 12.5 cc/hr* 2.5 U/hr
After Fingerstick has been between 80-140 x >2 hours, decrease
frequency of fingersticks to every 2 hours then every 4 hours.

49. HYPOGLYCEMIA DURING AN INSULIN DRIP
• For Glucose <60
– Turn off Insulin drip for 30 minutes
– Continue D5W (or D5LR) at 100 – 125 cc/hr
– Recheck Glucose after 30 minutes
– If blood glucose on recheck is still <60
- Give 25 ml of D50 IV (or 10-12 grams glucose)
– Recheck Blood Glucose every 30 minutes
- Restart insulin when glucose >101 mg/dl

50. INSULIN DRIP FOR THE INSULIN RESISTANT
PATIENT
• Method for poorly controlled, morbidly obese or noncompliant
patients with gestational diabetes
• 50% of total daily insulin dosage divided by 24 hours provides initial
rate for insulin drip.
• EXAMPLE:
– Ms. Jones current insulin regimen
- AM: 80units NPH 45 units Regular insulin
- PM: 60 units NPH, 55 units Regular insulin
– Total daily dosage= 240 units per day.
– ½ of 240 units = 120 units
– 120 units / 24 hours = 5 units per hour as initial
dosage.

51. Management - Postpartum
• Use pre pregnancy insulin levels when on diet and
monitor.
• If GDM monitor sugars only
• Immediate postpartum goal is fingerstick < 200
• GDM – Repeat GTT at 6 weeks postpartum
• GDM - long term risk of NIDDM
• Contraception

52. THANK YOU !