Gestational Diabetes

1
Gestational Diabetes

• Adapted from
• Turok DK, Ratcliff SD, Baxley EG. Management of
  Gestational Diabetes Mellitus. Am Fam Physician
  2003 681767-72.

2
Gestational Diabetes

• Defined as
• Glucose intolerance that begins, or is first
  recognized, during pregnancy

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Gestational Diabetes

• Maternal Complications
• Increased risk of
• Pre-eclampsia
• Cesarean delivery
• Future type 2 diabetes

• Fetal Complications
• Higher rates of
• Perinatal mortality
• Macrosomia
• Birth trauma
• Hyperbilirubinemia
• Neonatal hypoglycemia

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Gestational Diabetes

• Initial screening
• 50g, 1 hr glucose challenge test
• 24-28 weeks gestation
• Normal lt130mg/dL or lt140mg/dL

more sensitive more false s
5

• If the screening test is abnormal
• 100g, 3 hr tolerance test
• 3 days unrestricted diet
• Overnight fast, 100g glucose load
• Venous blood samples are taken
• (1, 2, and 3 hrs)
• 2 or more abnormal values GD

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Gestational Diabetes

• Management
• Blood glucose monitoring
• Diet
• Exercise
• Insulin
• Oral Hypoglycemic Medications

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• Blood Glucose Monitoring
• Diet-controlled diabetes
• 4x per day, 2 days per week
• If 2 values per week exceed limits, begin more
  intensive treatment (insulin)

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• Diet
• Ideal diet remains to be defined
• Current recommendations
• A diet that meets the needs of pregnancy but
  restricts CHO to 35-40 of daily calories

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Clinical Note

• Elevated maternal serum ketone levels have been
  linked to reduced psychomotor development and IQ
  at 3-9 years
• (Rizzo, 1991 1995)
• Caloric restriction must be approached with
  caution!

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• Exercise
• Improves glycemic control
• Has not been shown to affect perinatal outcomes

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• Insulin
• gt105mg/dL (fasting) and
• gt120mg/dL (2hrs after meals)
• Reduced incidence of
• Macrosomia
• Less evidence
• Operative delveries
• Birth trauma

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• Oral Hypoglycemic Medications
• glyburide (Micronase), metformin (Glucophage)
• Not recommended
• teratogenicity?
• transport across the pacenta?
• neonatal hypoglycemia
• More research is needed

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Gestational Diabetes

• Antenatal Testing
• Recommended if
• blood glucose levels are not well controlled
• required insulin therapy
• concomitant hypertension
• Nonstress test OR
• Modified biophysical profile OR
• nonstress test amniotic fluid index
• Full biophysical profile

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Gestational Diabetes

• Delivery
• Most common complication shoulder dystocia
• 31 of neonates weighing gt4,000g
• Data does not support the use of C-section to
  avoid birth trauma
• 13 error rate estimating fetal weight by
  untrasound

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What is a reasonable approach?

• Offer elective C-section
• Estimated fetal weight gt4,500g
• Patient history and pelvimetry
• Discuss risks and benefits

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• No indications to pursue delivery before 40 weeks
  in patients with good glycemic control
• Unless other maternal or fetal indications are
  present

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Gestational Diabetes

• Postpartum Management
• Insulin resistance resolves quickly
• rarely require insulin in the postpartum period
• Breastfeeding
• improves glycemic control

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• Postpartum Management (contd)
• Higher risk for developing type 2 diabetes in the
  future
• Should be tested 6 weeks after delivery
• Screened annually thereafter
• Should be counseled about diet and exercise