GDM

Question 1

Risk factors for GDM

Answer 1

• being overweight or obese
• being physically inactive
• age (increased)
• having GD in a previous pregnancy
• having a very large baby (9 pounds or more) in a previous pregnancy
• having high blood pressure
• having a history of heart disease
• having polycystic ovary syndrome (PCOS)
• African, Asian, Hispanic, Native American, and Pacific Island descent.

Question 2

Complications from GDM - Mom

Answer 2

•	labor difficulties
•	cesarean birth
o	25% GDMA2, 17% GDMA1, 9.5% control
•	heavy bleeding after delivery
•	severe tears in the vagina or the area between the vagina and the anus with a vaginal birth
•	GHTN/PreE
o	PreE 10% in glucose controlled vs near 20% in poorly controlled
o	Fasting glucose less than 115 mg/dL

Question 3

Complications from GDM

Answer 3

• Jaundice (hyperbilirubinemia)
• Hypoglycemia (fetal hyperinsulinemia)
• Respiratory distress
• NICU
• LGA/macrosomia
• Shoulder dystocia (birth trauma)
• Still born
• Risk of childhood overweight, obesity, DM

Question 4

Early Testing/Diagnosis - GDM

Answer 4

• Overweight/obese + prior GDM
o Physical inactivity
o 1st degree relative with DM
o High risk race (Asian, African American, Latino, Native Amer, Pacific Is)
o Prior birth > 4000 g or 9 lb
o Previous GDM
o HTN (140/90) or on antihypertensive tx)
o HDL < 35 or Triglyceride > 250
o PCOS
o A1c > 5.7 or dx of impaired glucose tolerance
o History of cardiovascular dz
o Any signs of insulin resistance (BMI >40, acanthosis nigricans, etc)

Question 5

Treatment of GDM decreases:

Answer 5

Treatment leads to decreased rates of:
• Serious newborn complications
• Perinatal death
• Shoulder dystocia (birth trauma, fracture, nerve palsy)
• PreE (18% down to 12%) and hypertensive disorders
• LGA/macrosomia (22% down to 13%)
• Birth weight greater than 4000 g (21% down to 10%)
• Cesarean section risk

Question 6

o	Insulin – recommended
	Does not cross placenta
	Starting dose 0.7-1.0 units/kg
	Divide into long acting vs intermediate acting vs short acting
	Target the elevated values

Answer 6

Type Onset Peak Duration
Short Insulin lispro 1-15 min 1-2 hr 4-5 hr
Short Insulin aspart 1-15 min 1-2 hr 4-5 hr
Short Regular insulin (more hypoglycemia) 30-60 min 2-4 hr 6-8 hr
Intermed. NPH (isophane insulin suspension 1-3 hr 5-7 hr 13-18 hr
Long Insulin glargine 1-2 hr No peak 24 hr
Long Insulin detemir 1-3 hr Min peak 8-10 hr 18-26 hr

Question 7

 Metformin

Answer 7

o Biguanide – inhibits hepatic gluconeogenesis and glucose absorption; stimulates glucose uptake in peripheral tissues
o Used in pregestational DM and PCOS (continue until end of 1st TM)
o Crosses the placenta – unknown long-term sequelae for offspring
o Metformin is not superior to insulin, does cross the placenta , and we don’t have long-term data in exposed offspring, may eventually require insulin
o Dose 500 mg nightly for 1 week then 500 mg BID
o Check creatinine prior to tx (not to be used in chronic renal dz)
o SE – abdominal pain, diarrhea (inc dose slowly and take w/meals to minimize SE)
o Max dose of 2500 to 3000 mg per day in 2-3 divided doses

Question 8

 Glyburide

Answer 8

o Sulfonylurea – binds to pancreatic beta-cell adenosine triphosphate potassium channel receptors to increase insulin secretion and insulin sensitivity of peripheral tissues
o DO NOT USE in sulfa allergy
o Crosses the placenta
o Should not be 1st line – doesn’t yield equivalent results as insulin or metformin
o Higher risk of macrosomia and neonatal hypoglycemia but very similar glucose control
o Studies have not shown statistically significant difference between glyburide and insulin
o Dose 2.5 up to 20 mg daily in divided doses (may need up to 30 mg/d)
o Long-term outcome of offspring not available

Question 9

Management of GDM

Answer 9

• Begin nutrition therapy/dietary counseling then begin surveillance of blood glucose levels (individualized plan with dietitian based on indivdual’s BMI)
o Carbohydrates 33%-40% of daily calories (complex carbs are better than simple carbs)
o 20% protein 40% fat
• Generally check 4 times daily (fasting and after each meal)
• 1 hour PP vs 2 hour PP
• F – less than 95 and PP < 140 at 1 hr and < 120 at 2 hr

Fetal kick counts
NST
BPP (breathing, movement, muscle tone, NST, AFI)
Growth US (macrosomia is more common and shoulder dystocia is more likely at any given fetal weight)

Question 10

Timing of delivery in GDM

Answer 10

A risk of fetal demise does exist in pregestational DM with supoptimal glycemic control
Antenatal fetal testing for GDMA2 or with poor glycemic control at 32 weeks
For GDMA1 testing may not be necessary prior to 40 weeks
Should test AFI due to risk of polyhydramnios caused by fetal hyperglycemia

Delivery at 38-39 weeks lowers c-section rate and decreases shoulder dystocia
GDMA1 (controlled)– delivery between 39w0d and 40w6d
GDMA2 (controlled) – delivery bewtween 39w0 and 39w6
GDMA (poorly controlled) – delivery between 37w0 and 38w6
34w0 to 36w6 should be reserved for failed in-hospital glycemic control

Recommend c-section in GDM if fetal weight is >4500 g