This article describes the rationale for intensive treatment with these agents and other interventions to prevent both hypoglycemia and hyperglycemia.
Intensive therapy requires:
- memory-based self-monitoring of blood glucose, which empowers patients to take charge of glycemic control and provides feedback on the timing and dose of insulin administration,
- dietary regulation,
- strict criteria for initiation of pharmacologic therapy,
- multiple injections of insulin or its equivalent when diet alone is insufficient, and
- an interdisciplinary management team.
Blood glucose goals
Regardless of the treatment, the primary goal is always to achieve glycemic control, because it reduces the incidence of hypoglycemia, hyperglycemia, and ketosis. For type 1 and type 2 diabetes, glycemic control is important to prevent further deterioration of complications such as vasculopathy and nephropathy.
Goals of treatment are achieving the following blood glucose concentrations (in milligrams per deciliter):
- mean: 90 to 105
- fasting: 60 to 90
- preprandial: 80 to 95
- postprandial: less than 120
In the process, the clinician needs to anticipate how pregnancy will affect preexisting disease, and how diabetes will affect pregnancy outcomes, in patients with any of the 3 types of diabetes.
2 diet protocols
For all types of diabetes, the foundation is diet—specifically, using nutritional therapy to achieve and maintain a maternal blood glucose profile comparable to that of a nondiabetic woman.
Two approaches are recommended:
- reducing carbohydrate intake to 40% to 50% of total calories or
- limiting carbohydrate consumption to foods with a low glycemic index for approximately 60% of calories.
Calculating calories: Same for all
- For a BMI less than 20 (underweight), daily caloric intake should be 35 to 38 kcal/kg.
- For a BMI of 20 to 25 (normal weight), the patient should consume 30 kcal/kg.
- For a BMI of 26 and higher (overweight, obese, morbidly obese), caloric intake should be 20 to 25 kcal/kg.
In addition, the daily allotment of calories is divided into 3 main meals and 3 to 4 snacks, with adjustments for the patient’s time constraints, work schedule, and other individual factors.
To encourage compliance, the diet also should reflect the patient’s cultural preferences.
How do you know when diet fails?
Women with pregestational diabetes are usually already taking insulin or other pharmacologic agents by the time they conceive. There is no consensus or hard data on how long a woman who develops gestational diabetes mellitus should remain on a diet before starting drug treatment.
In a study evaluating the time required to achieve glycemic control with diet alone during a 4-week period, 70% of patients with fasting plasma below 95 mg/dL achieved established levels of glycemic control within 2 weeks with no substantial improvement thereafter.8,9 In contrast, in patients with fasting plasma glucose of more than 95 mg/dL, most patients failed to achieve the desired level of glycemic control throughout the 4-week period.