Gestational Diabetes

Question 1

Of the following, which would least likely predispose to gestational diabetes?
A. Age of 27 at conception
B. Previous term baby weighing 9 lbs
C. Maternal BMI of 40 kg/m2
D. Samoan (Pacific Islander) origin
E. Paternal great aunt with impaired glucose tolerance

Answer 1

E. Paternal great aunt with impaired glucose tolerance

Question 2

What are the levels for impaired fasting glucose (IFG)?

Answer 2

100-125

Question 3

100-125 is characteristic of what abnormal glucose?

Answer 3

Impaired fasting glucose (IFG)

Question 4

What is the range for impaired glucose tolerance (IGT)/

Answer 4

140-199

After glucose challenge

Question 5

140-199 after glucose challenge is characteristic of what abnormal glucose?

Answer 5

Impaired glucose tolerance (IGT)

Question 6

Describe screening for GDM during 24-28 weeks gestation

Answer 6

Two step approach in US
Screen with 50 gm oral glucose challenge with single plasma glucose drawn at one hour (less than 130 is normal)
If greater than 130, then proceed with 100g oral glucose challenge in a fasting state (no caloric intake for at least 8 hours prior to test)

Question 7

Describe the 100 gm challenge

Answer 7

2 elevated values is positive test for GDM

Fasting

Question 8

What are the risk factors for gestational diabetes?

Answer 8

Maternal obesity (>110% ideal weight or BMI over 30kg/m2)
Maternal age over 25
Previous delivery of baby larger than 9 lbs
History of unexplained perinatal loss or malformation
Family history of diabetes (first degree relatives)
Glycosuria at first pre-natal visit
Metabolic syndrome: 3 or more risk factors associated with atherosclerotic disease and T2DM (insulin resistance, elevated fasting glucose, HTN, elevated triglycerides, reduced HDL cholesterol, abdominal obesity)
Polycystic ovarian syndrome (PCOS)
Hypertension
Glucocorticoid use at time of pregnancy
Ethnic groups with high prevalence of T2DM (Hispanic, African American, Native American, South or East Asian, Pacific Islander)

Question 9

32 y/o obese female presents for physical. No prior medical or surgical history. Irregular menses at every 28-42 days, but no changes in flow or prior pregnancies. Urine pregnancy test is negative. Fasting glucose is 122. What best classifies her pre-pregnancy glucose status?
A. Gestational diabetes mellitus
B. T1DM
C. T2DM
D. Impaired glucose tolerance
E. Impaired fasting glucose

Answer 9

E. Impaired fasting glucose (100-125)

Question 10

Describe how fetus becomes larger due to GDM

Answer 10

Mother’s blood brings extra glucose to fetus
Fetus makes more insulin to handle extra glucose
Extra glucose gets stored as fat and fetus becomes larger than normal

Question 11

What are the maternal complications of GDM?

Answer 11

Stillbirth
Preeclampsia (new onset of HTN (>140/190) and proteinuria after 20 weeks gestation)
Babies that are large for gestational age (LGA) or macrosomic
Can result in perineal lacerations in vaginal birth
May prompt C-section delivery
Hydramnios

Question 12

What are the increased long term risks for mother with GDM?

Answer 12

T2DM
T1DM
Cardiovascular disease

Question 13

What are the fetal complications of GDM?

Answer 13

Shoulder dystocia
Brachial plexus injury
Birth trauma (contusions, large hematoma from vacuum extraction, hypoxia/acidosis)
Increased long term risk of obesity and metabolic syndrome

Question 14

For what should a baby born from a mother with GDM be monitored post-natally?

Answer 14

Hypoglycemia (severe risk)

Hyperbilirubinemia (especially with contusions or hematoma)

Question 15

28 y/o obese Hispanic female delivers baby weighing 10 lbs by C-section. Which would you advise mother?
A. Subsequent babies will be normal weight
B. Newborn’s blood sugar will be high after delivery
C. Newborn will maintain a normal weight into adulthood
D. Her blood pressure will remain normal
E. She has a higher risk of T2DM

Answer 15

E. She has a higher risk of T2DM