Treatment Guideline Chart
Gestational diabetes mellitus (GDM) is any degree of glucose intolerance with onset or first recognition during pregnancy.
Hyperglycemia in pregnancy may be suggested by the presence of glycosuria, a fetus that is large for date, or polyhydramnios.
Overt diabetes mellitus may be found in women presenting with risk factors for type 2 diabetes during the first prenatal visit (before 13 weeks of gestation).

Gestational%20diabetes%20mellitus Treatment


Insulin Preparations

  • Insulin is the 1st-line pharmacotherapy recommended for GDM when MNT fails to maintain glycemic control
    • Given also to women with GDM when Metformin is contraindicated or unacceptable to patient
  • Human insulin should be used in pregnant women because it is the least immunogenic
    • Rapid-acting insulin analogs develop antibodies similar to human insulin
    • Insulin with low antigenicity minimizes transplacental transport of insulin antibodies
      • Currently available human insulin preparation has shown to not cross the placenta
  • Multidose regimen of insulin administration may be needed for better control of blood glucose levels
  • Individualize therapy and regularly adapt to the changing needs of pregnancy to meet glycemic control goals
  • Exact time course of each insulin will depend on each particular preparation, presence of antibodies in the patient and site of injection
  • Immediate treatment with Insulin, with or without Metformin, is considered in women with GDM who have a fasting plasma glucose of 6-6.9 mmol/L with complications eg macrosomia or hydramnios and is offered to women with GDM who have a fasting plasma glucose of ≥7 mmol/L at diagnosis
  • May be given in women with history of GDM and prediabetes, but not recommended as a 1st-line therapy
  • May also be given if diet and exercise within 1-2 weeks failed to meet blood glucose targets and for patients not in their 1st trimester who cannot use or refuse Insulin or Glibenclamide 
  • May be used as an alternative in some women who may not be able to use Insulin safely or effectively due to cost, comprehension or cultural factors, but only after thorough discussion of known risks and the need for more data on long-term safety
  • Metformin crosses the placenta but risk of neonatal hypoglycemia and maternal weight gain may be lower than with Insulin
  • Should be stopped by the end of the 1st trimester if used to treat polycystic ovary syndrome and induce ovulation
  • Should not be given in pregnant women with hypertension, preeclampsia or with risk for intrauterine growth restriction
  • May be given with intensive lifestyle modification in postpartum women with a history of GDM who were found to have prediabetes
    • Delays or prevents progression to diabetes in women with history of GDM and prediabetes
  • Initial dose is 500 mg orally once daily with food, titrated up to a max dose of 2.5 g/day
  • Long-term safety data are not available 

Glibenclamide (Glyburide)

  • May be used as alternative for patients with GDM who are unable or unwilling to take Insulin, who cannot tolerate Metformin, or whose blood glucose targets are not met with Metformin but refuses Insulin
  • May be used as an alternative in some women who may not be able to use Insulin safely or effectively due to cost, comprehension or cultural factors, but only after thorough discussion of known risks and the need for more data on long-term safety
  • Useful adjunct to MNT and physical activity regimens when additional treatment is necessary to maintain appropriate glucose levels
    • Safe and effective in controlling glucose levels in >80% of patients with GDM
  • Has been shown to cross the placenta and is associated with higher rate of neonatal hypoglycemia and macrosomia compared to Insulin or Metformin
  • Initial dose is 2.5 mg orally once daily before meals, titrated up to a max dose of 20 mg/day  
  • Long-term safety data are not available 
Drug Onset of Action (hr) Peak Effect (hr) Duration of Action (hr)
Insulin aspart 0.17-0.33 1-3 3-5
Insulin glulisine 0.17-0.33 1.6-2.8 3-4
Insulin lispro 0.25 0.5-1.5 2-5
Insulin regular 0.5 1-3 4-12 (dose-dependent)
Insulin NPH 1.5 4-12 24
Insulin detemir 1.1-4 3-4 24
Insulin glargine 3-6 no peak 24
*Please see Insulin Preparations clinical reference table for further information

Non-Pharmacological Therapy

Medical Nutrition Therapy (MNT)

  • Cornerstone of GDM management
    • Preconception care should be accessible to all females with pre-existing DM to ensure adequate nutrition and glucose control prior to conceiving, during pregnancy, and postpartum
  • Best prescribed by a registered dietitian or a healthcare provider with experience in managing patients with GDM 
  • Patient should be counseled about individual MNT based on their height and weight
  • Should include adequate calories and nutrition to meet needs of mother and fetus
  • More complex carbohydrates, more fiber, lean protein, oily fish, and a balance of polyunsaturated fats and monounsaturated fats are recommended
    • Carbohydrate reduction to 35-40% of daily energy intake has been shown to decrease hyperglycemia and improve maternal and fetal outcomes
  • Obese patients may benefit from calorie restriction (approximately 25 kcal/kg actual body weight/day)
    • Shown to decrease hyperglycemia and triglycerides and does not seem to increase ketonuria 
  • Avoid inappropriate weight loss or gain and avoid ketonuria
    • Recommended weight gain during pregnancy for overweight women is 6.8-11.4 kg and 4.54-9 kg for obese women
  • Should be adjusted to meet glycemic control goals
    • If MNT fails to meet glycemic control goals within 1-2 weeks, Insulin administration should be considered

Moderate Exercise

  • Physical activity is encouraged unless medical or obstetrical contraindication exists or glycemic control is worsened by activity
  • Regular aerobic exercise for at least 30 minutes daily has been shown to lower maternal blood glucose levels
  • Physical activity of at least 3 days per week is encouraged
  • Examples of moderate physical activity include brisk walking, water aerobics, stationary cycling and household chores
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