43. Gestational Diabetes

Question 1

T/F: pregnancy is an insulin resistant state

Answer 1

True

It is mediated by GH, CRH, placental lactogen

Increase in prolactin, progesterone, cortisol

Question 2

Glucose intolerance diagosed in pregnancy

Answer 2

Gestational diabetes

Question 3

Gestational diabetes is typically diagnosed based on ________ Classification System

Answer 3

White’s

Question 4

Compare/contrast type A1 vs. type A2 based on White’s classification system

Answer 4

Type A1 = gestational diabetes; diagnosed in pregnancy and controlled with diet alone (no meds)

Type A2 = gestational diabetes; diagnosed in pregnancy and controlled with diet and glyburide or insulin

Question 5

Risk factors for gestational diabetes

Answer 5

Overweight (BMI >25) and…

• FH of diabetes
• High risk race/ethnicity
• Previous LGA infant
• Previous GDM
• HTN
• PCOS
• A1c >5.7%
• Hx of CVD

Question 6

When do you typically screen for gestational diabetes?

Answer 6

24-28 weeks

Question 7

T/F: physicians should screen on risk factors for GDM alone

Answer 7

False, then we would miss 50% of cases

Question 8

What are the current screening recommendations for GDM?

Answer 8

Screen ALL patients between 24-28 wks

2 step approach: 1 hr glucola (50g glucose tolerance test) — abnormal result is 130-140 mg/dL, if abnormal proceed to 3 hr GTT

If initial result is >200 mg/dL proceed to diabetic education

Question 9

What is the difference between the 1 hr glucola and 3 hr GTT?

Answer 9

1 hr glucola does not need to be fasting as result is not dependent on prior oral intake

3 hr GTT must be fasting, requires 2 abnormal values to be diagnostic

Question 10

What are some alternative screening regimens for GDM?

Answer 10

2 hr GTT (75 g load)

HgA1c

Fasting glucose

Random glucose monitoring

Question 11

What are the 2 first line antepartum guidelines for GDM?

Answer 11

Dietary changes: caloric intake based on weight - baseline 30 kcal/kg, 50% carbs, 25% protein, 25% fat

Exercise: moderate exercise 3-5x/week with goal of 150 min/week, walking after meals which greatly improves glucose control

Question 12

What is the testing regimen like for GDM?

Answer 12

Daily monitoring — fasting and 1 or 2 hr postprandial

[peak postprandial glucose occurs at 90 min]

may not need to test as much for well controlled pts

Question 13

Fasting glucose should be ______

1 hr postprandial should be ____

2 hr postprandial should be ____

Answer 13

<95 mg/dL

<140 mg/dL

<120 mg/dL

Question 14

T/F: with dietary changes, 70-80% of those with GDM can achieve euglycemia

Answer 14

True

Question 15

What are examples of oral hypoglycemic agents?

Answer 15

Glyburide

Metformin

Question 16

In terms of medication, what is first line tx for GDM? Why?

Answer 16

Insulin; bc it does not cross placenta

Question 17

MOA of metformin

Answer 17

Inhibits hepatic gluconeogenesis and glucose absorption

Stimulates glucose uptake in peripheral tissues

Question 18

Why is metformin chosen less frequently than insulin for GDM?

Answer 18

It crosses the placenta, although there are no recorded long term data on neonatal effects

Question 19

Adverse effects of metformin

Answer 19

Diarrhea, abdominal pain

26-46% will still require tx with insulin

Question 20

Benefits of metformin

Answer 20

Good option for cost, administration, and compliance

Question 21

MOA of glyburide

Answer 21

Binds pancreatic beta cell ATP/K receptors

Increases insulin sensitivity in peripheral tissues

Question 22

Studies are mixed about glyburide, but placental crossing is likely minimal. However, fetal _____ may be a side effect

Answer 22

Hypoglycemia

Question 23

Maternal risks associated with GDM

Answer 23

Preeclampsia
LGA
Delivery trauma

Question 24

Mothers with GDM have a 4x higher likelihood of developing _____ in the first 5 years

Answer 24

T2DM

[also 10x more likely in first 10 years, 60% of latin american women develop within 5 yrs of pregnancy]

Question 25

Fetal risks of GDM

Answer 25

Macrosomia

Neonatal hypoglycemia

Hyperbilirubinemia

Shoulder dystocia

Birth trauma

Stillbirth

Increased risk of childhood and adult onset obesity and diabetes

Question 26

When and how do you monitor a mother with GDM?

Answer 26

Monitoring of fetus begins at 32 weeks with NST and biophysical profiles

Serial amniotic fluid measurements

US for growth

Question 27

Which form, A1 or A2, has lower risk with less monitoring required?

Answer 27

A1

Question 28

When is delivery recommended for mothers with GDM?

Answer 28

A1DM = deliver after 39 wks

A2DM = deliver after 39 wks

Preexisting diabetes = 38-39 wks

Poorly controlled = 37-39 wks

Question 29

In terms of intrapartum management, the goal of identification and management are reduction of fetal risks of what 3 conditions?

Answer 29

Preeclampsia
LGA
Shoulder dystocia

Question 30

What are other goals of intrapartum management in mothers with GDM?

Answer 30

Optimal glycemic control during labor, which allows effective contractions/labor progression, and optimal environment for infant at delivery

Question 31

Goals for postpartum GDM management

Answer 31

2 hr oral GTT after 6 wks postpartum

PCP f/u

Preventative therapy — impaired fasting glucose, impaired glucose tolerance, diabetes

Repeat screening every 1-3 years after delivery