Gestational DiabetesTesting Paradigms in a Rural Office

November 7, 2014

Learning Objectives

• Understand normal glucose levels in pregnancy.

• Define Gestational Diabetes Mellitus

• Understand testing for Gestational Diabetes Mellitus

What's normal?

Patterns of Glycemia in Normal Pregnancy: Should the current therapeutic targets be challenged? Teri Hernandez PhD RN et al ; Diabetes Care July 2011 34:7 p. 1660-1668.

• Pooled Analysis of approximately 45 years of data concerning pregnant women with normal BMI and normal glucose tolerance.

• FBS = 71 mg/dl

• 1 Hour postprandial = 109 mg/dl

• 2 Hour postprandial = 99 mg/dl

When did we start testing and how?

• Non challenge testing (Risk factors only)

• Challenge Testing• 1973 O'Sullivan and Mahan proposed the one hour glucose tolerance test.

• 2010 International Association of Diabetes and Pregnancy Study Group recommended a single 2 hour diagnostic glucose challenge test.

• Alternative Testing• Jelly Beans, Candy Bars, Proscribed Meals

A Word About Statistics

Sensitivity• Positive in disease

• How many people who have the diagnosis are identified as positive.

Specificity• Negative in Health

• How many people without the diagnosis are identified as negative.

DataOne year prior and one year following start of 2

hour GTT

One hour GTT: 259• Positive screens: 68

• Positive 3 hour gtt: 11 (4.2%)

• Time to teaching: 16.4d (7-35d)

Two hour GTT: 286• Positive tests: 29 (10.1%)

• Time to teaching: 6.5d (0-15d)

Cost….

Are making a difference?

Why do we care?

Outcomes

Australian Carbohydrate Intolerance Study in Pregnant Women, 2005 1,000 women

NICHD Maternal Fetal Medicine Network, 2009 958 women

Hyperglycemia and Adverse Pregnancy Outcome Study 15 Centers; 9 Countries; 23,316 women 1 Hour GTT

Summary

• How do we test for Gestational Diabetes.• ACOG continues to recommend the 2-step diagnostic approach to

screening.

• What are normal values in pregnancy.

• Importance of diagnosis and management.• Are we teaching for the future?