Pregnancy management of women with gestational diabetes (GDM)

Gestational diabetes (GDM) is a state of carbohydrate intolerance of varying degrees and it is first recognized during pregnancy with a probable resolution after the end of pregnancy. Since this condition is present for a limited time period, patients may not understand the importance of glycemic control to reduce the potential risk to their fetuses. Therefore patient education is important and it should be done early as possible. Followings are key points that should be considered in the management of GDM.
1. Dietary therapy
2. Glucose monitoring
3. Insulin therapy
4. Oral hypoglycemic agents

Dietary therapy
It is very difficult to manipulate diet during pregnancy. During the first trimester patient may experience nausea and vomiting therefore food intake can be low. Metabolic management of a patient with GDM is focused on dietary control, regular home glucose monitoring, and judicious use of insulin therapy.
Most patients with GDM diagnosed in the third trimester can maintain 1-hour postprandial blood glucose levels less than 130 mg/dl via diet manipulation alone (ie, multiple, small, nonglycemic meals and increased exercise).

Glucose monitoring
This is an essential part in the management of GDM. Patient should be educated how to monitor blood glucose level and to adjust the insulin amount according to the blood glucose level. A home glucose monitor is also essential to assist the patient in choosing the types and timing of food ingestion.
Once the patient has demonstrated success in controlling postprandial glucose with diet, the occurrence of abnormal fasting levels is exceedingly rare and the morning checks can be discontinued. Fasting checks are reinstituted if any postprandial glucose levels are abnormal.

Insulin therapy

Insulin therapy is the mainstay of treatment for GDM. Determine the insulin regimen based on the patient's individual glucose profile. Typically, one to several postprandial glucose levels become consistently above target because the patient's ability to compensate for rising insulin resistance with diet becomes inadequate. When more than 20% of postprandial blood sugar values exceed 130 mg/dl, administering rapid-acting lispro or aspart insulin injections (4-8 U to start) before meals is usually successful in controlling glucose overshoots. If more than 10 U of short-acting insulin is needed prior to the noon meal, adding an 6-12 U dose of neutral protamine Hagedorn (NPH) insulin prior to breakfast helps achieve smoother control. When more than 10% of fasting glucose levels rise above 95 mg/dL, a starting dose of 6-8 U of NPH insulin at bedtime can be used.
The doses are scaled up as necessary once or twice weekly to keep glucose levels on target.
Insulin pumps can be used to administrate insulin. This is more convenience for the patients but it is expensive when compare with insulin syringes.


Oral hypoglycemic agents
This is a controversial topic as the most of oral drugs are teratogenic, but there are some drugs with safe profile
Glyburide is a second generation sulfonylurea. It has a safe profile as it does not cross the placenta. Therefore this drug can be used in management of GDM.