ACOG practice bulletin: pregestational diabetes mellitus

Question 0

How often should patients with diabetes in pregnancy be seen?

Answer 0

Every 1-2 weeks during first two trimesters and weekly after 28 weeks

Question 1

What is the rate of pre-gestational DM?

Describe the cause of type 1.

Describe the cause of type 2.

Answer 1

1% of all pregnancies

Autoimmune destruction of pancreatic beta cells

Peripheral insulin resistance, relative insulin deficiency, obesity

Question 2

What nutritional guidance is suggested for pre-gestational DM?

Answer 2

Referral to nutritionist
Calorie requirement increased approximately 300 kcal above basal need
Normal body weight requires 30-35 kcal/kg per day
Calories should include 40% complex carbohydrates, 20% protein, 40% unsaturated fat
Calories should be distributed 20% at breakfast, 30% at lunch, 30% at dinner and up to 30% for snacks, especially bedtime snack to reduce nocturnal hypoglycemia

Question 3

How does insulin need change with advancing pregnancy?

Answer 3

Increases during each trimester with most marked change between 28-32 weeks

Question 4

What is the goal blood glucose levels for fasting and one hour postprandial?

What is the goal mean capillary glucose level?

What is the upper limit for hemoglobin A1C?

Answer 4

95 and 140 mg/dL

100 mg/dL

No higher than 6%

Question 5

When should regular insulin and insulin lispro be given related to meals?

Answer 5

Regular insulin should be given 30 minutes before eating. Lispro should be taken immediately (but hypoglycemia will develop quickly if no food is consumed)

Question 6

A hemoglobin A1C of 8% reflects a mean glucose level of what?

What rule of thumb is used to interpret higher or lower hemoglobin A1C values?

Answer 6

180 mg/dL

Each 1% higher or lower than 8% equals a change of 30 mg/dL

Question 7

What should patients with DM do if their glucose level exceeds 200 mg/dL?

Answer 7

Check for urine ketones and notify provider if positive

Question 8

What blood glucose level is concerning for hypoglycemia?

How should this be treated?

Answer 8

Less than 60 mg/dL

A glass of milk; glucagon for severe hypoglycemia and loss of consciousness

Question 9

What maternal complications are associated with pre-gestational DM?

Answer 9

Diabetic retinopathy: blindness, progression with hypertensive disease
Diabetic nephropathy: hypertensive disease, uteroplacental insufficiency, iatrogenic preterm birth
Chronic hypertension: increased risk of preeclampsia, uteroplacental insufficiency, stillbirth
Coronary artery disease: May be a contraindication to pregnancy due to increased risk of MI and death

Preeclampsia in 15-20% without nephropathy, 50% with nephropathy
Increased rate of cesarean delivery

Question 10

What is the leading cause of blindness between age 24 and 64?

How is it classified?

Answer 10

Diabetic retinopathy

1. Background retinopathy: retinal microaneurysms and dot-blot hemorrhages
2. Proliferative retinopathy: marked by neovascularization, best treated with laser therapy before conception

Question 11

What percentage of pregnancies with pre-gestatational diabetes will develop diabetic ketoacidosis?

Answer 11

5-10%

Question 12

What are risk factors for diabetic ketoacidosis?

Answer 12

New onset diabetes, infections such as influenza or UTI, poor patient compliance, insulin pump failure, treatment with beta-mimetic tocolytics and antenatal corticosteroids

Question 13

How does diabetic ketoacidosis typically present?

What lab findings are characteristic?

Answer 13

Abdominal pain, nausea and vomiting, altered mental status

Low arterial pH less than 7.3, low serum bicarb less than 15 mEq/L, elevated anion gap, positive serum ketones

Question 14

What is maternal mortality rate from diabetic ketoacidosis?

What is fetal mortality rate?

Answer 14

Rare

10-35%

Question 15

Describe management of DKA during pregnancy.

Answer 15

Labs: ABG, glucose, ketones, electrolytes every 1-2 hours
Insulin load 0.2-0.4 U/kg, maintenance 2-10 U/hr
Normal saline 1 L in first hour, 500 mL/hr for 2-4 hours, 250 mL/hr
5% dextrose in NS when plasma reaches 250 mg/dL
Potassium if needed
One ampule of bicarbonate if pH is < 7.1

Question 16

What is the rate of congenital anomalies with pre-gestational DM

What anomalies are associated?

Answer 16

6-12%

Complex cardiac defects, CNS anomalies such as anencephaly and spina bifida, skeletal malformations with sacral agenesis most common

Question 17

What fetal anomaly rate is associated with hemoglobin A1C of 5-6%

Near 10%?

Answer 17

Close to normal pregnancy rate, 2-3%

20-25%

Question 18

Other than birth defects, what other fetal complications are associated with pre-gestational diabetes?

Neonatal complications?

What are the long-term risks to children of mothers with pre-gestational diabetes?

Answer 18

Shoulder dystocia, macrosomia

Neonatal hypoglycemia, higher rate of respiratory distress syndrome, polycythemia, organomegaly, electrolyte disturbances, hyperbilirubinemia

Obesity and carbohydrate intolerance

Question 19

What should be recommended at preconceptual counseling for women with diabetes?

Answer 19

Emphasize euglycemic control before pregnancy and adverse outcomes of poor control
Retinal examination by ophthalmologist
24 hour urine collection for protein excretion and creatinine clearance
EKG
Thyroid function studies for women with type one diabetes (40% risk of thyroid dysfunction)
At least 400 µg of folic daily

Question 20

What does ACOG say about oral hypoglycemic agents for pre-gestational diabetes?

Answer 20

Should be limited and individualized until data regarding the safety and efficacy become available

Question 21

What fetal assessment is appropriate for women with pre-gestational diabetes?

Answer 21

Early ultrasound for viability and dating
Targeted ultrasound at 20 weeks
Fetal echocardiogram, particularly if heart and great vessels are not well visualized on previous imaging
Serial growth ultrasound
Daily kick counts and twice weekly NST at 32 weeks
Umbilical artery Dopplers for poor glucose control, vascular complications, poor fetal growth

Question 22

When should delivery occur in women with pre-gestational diabetes?

What does ACOG recommend for delivery before 39 weeks?

When is cesarean considered?

Answer 22

Between 39 0/7 and 39 6/7.

Amniocentesis for fetal lung maturity

Estimated fetal weight greater than 4500 g

Question 23

What should be the upper limit of blood glucose levels during labor?

Answer 23

110 mg/dL

Question 24

Describe insulin management during labor and delivery.

Answer 24

Morning dose of insulin is withheld
Begin IV NS infusion
Check glucose hourly
Regular insulin at 1.25 U/hr if glucose exceeds 100 mg/dL
Once labor begins or glucose is less than 70 mg/dL, change infusion to 5% dextrose at 100-150 mL/hr