••• Chapter 14^ Management of Medical and Surgical Conditions in Pregnancy^145
❍ What does hemoglobin A1c reflect?
It reflects the glycemic control over the past 2 to 3 months. A HbA1c level of 8% indicates a mean glucose level of
180 mg/dL, with each 1% higher or lower equal to a change of 30 mg/dL.
❍ When should regular insulin be given?
30 minutes prior to eating.
❍ How does pregnancy affect diabetic retinopathy?
It may cause acute progression of retinopathy.
❍ What are the laboratory findings associated with diabetic ketoacidosis?
Low arterial pH (<7.3), a low serum bicarbonate level (<15 mEq/L), an elevated anion gap, and positive serum
ketones.
❍ What does the treatment of diabetic ketoacidosis include?
Laboratory assessment, IV insulin, IV hydration, repletion of glucose, potassium, and bicarbonate as needed.
❍ What is the loading dose of insulin?
0.2 to 0.4 units/kg, followed by maintenance of 2 to 10 units per hour.
❍ Does glyburide cross the placenta?
No.
❍ What are the pharmacokinetics of glyburide?
Onset is 4 hours and duration is 10 hours.
❍ When should antenatal testing be initiated?
At 32 to 34 weeks, or earlier in complicated pregnancies. Testing should include twice weekly nonstress tests.
Doppler velocimetry of the umbilical artery may be useful in cases with vascular complications and poor
fetal growth.
❍ When should cesarean delivery be considered in a gestational diabetic patient?
When EFW is >4500 g.
THYROID DISEASE
❍ Which of the thyroid function tests increase during pregnancy?
Thyroid-binding globulin (TBG), total thyroxine (TT4), and total triiodothyroxine (TT3).
❍ When does the fetal thyroid begin concentrating iodine?
Between 10 and 12 weeks; however, maternal thyroxine (T4) remains important throughout pregnancy. Maternal
thyroxine accounts for 30% of thyroxine in the fetal serum at term.