Management of Gestational Diabetes

Transcription

1 Management of Gestational Diabetes A Diabetes risk assessment should be ascertained at the First prenatal visit. Low Risk: Early blood glucose screening is NOT routinely required if most of the following characteristics are present: No known diabetes in a first-degree relative Age < 25 years Normal Pre-pregnancy weight (BMI between 19-24) No history of abnormal glucose metabolism No history of a poor prior obstetric outcome Normal infant birth weights in previous pregnancies Women with low risk characteristics should be screened with a 50 gram 1 hour OGTT at weeks gestation. Abnormal glucose results of >130<185 should be promptly followed by a 100 gram 3 hour OGTT within 2 weeks. A diagnosis of Gestational Diabetes is determined if any of the 2 values are equal to or greater than the following: Fasting 95 1 Hour Hour Hour 140 The 3 hour OGTT should NOT be performed if the Fasting glucose is equal to or greater than 105 mg/dl. After a diagnosis of Gestational Diabetes is made, the goal is to promptly refer the woman to the Diabetes Nurse Educator and/or the Endocrinologist for immediate glucose management by 30 weeks gestation.

2 High Risk: Consider screening women with high risk characteristics at the First prenatal visit. BMI > 35 Previous history of glucose intolerance Previous Gestational Diabetes Previous delivery of a large-for-gestation-age infant (>4000G) Previous unexplained stillbirth Previous history of PCOS Glycosuria at the first prenatal visit History of diabetes in first-degree relative Early initial screening may be a Random Glucose, a Fasting Glucose, an A1c, or a 50 gram 1 hour OGTT. For values of a Random Glucose >200, or a Fasting Glucose > 126, an A1c >6.5%, or a 50 gram 1 hour OGTT > 185, refer to Diabetes Nurse Educator and/or Endocrinologist for immediate glucose management as this is a diagnosis of overt Diabetes. No further testing is required. For lower, but still abnormal, values of Random Glucose >130<200, Fasting Glucose >95<126, an A1c >5.7% <6.4%, or 50 gram 1 hour OGTT >130<185, arrange for an expeditious diagnostic 3 hour OGTT. If results of early initial screening are normal, arrange for 50 gram 1 hour OGTT at weeks gestation according to standard protocol. If a patient is diagnosed with GDM, refer the patient to consult with the certified diabetic nurse educator at Mount Auburn Hospital s Diabetes Education Program. Stacey DiModica RN BSN CDE Becky Anthony RN BSN CDE

3 Medical Nutrition Therapy (MNT) Dietary management is the foundation for the treatment of GDM. The Institute of Medicine and National Research Council released new guidelines for weight gain during pregnancy in May The recommended weight gain for pre-pregnancy BMI is : Underweight: total weight gain range lbs. Normal weight: total weight gain range lbs. Overweight: total weight gain range lbs. Obese: total weight gain range lbs. ADA recommends a therapeutic dietary intake that starts with kcal/day with 40-45% Carbohydrate (complex and high fiber), 30% Protein, and 25-30% Fat. Consider the suggestion from Jovanavic: 30 kcal/kg for normal weight 24 kcal/kg for overweight 12 kcal/kg for obese Limit carbohydrate consumption to: grams at Breakfast grams at Lunch and Dinner grams at Snacks Distribute the carbohydrate grams in 3 meals and 3 snacks across the day. Allow for 2-3 hours between each meal and snack. Calorie restriction is NOT recommended due to the risk of ketonemia.

4 You can refer patients to the Outpatient Nutrition Counseling service at Mount Auburn Hospital if the patient requires additional nutrition education. Instruct the patient to phone to schedule an appointment. Urine Ketone Testing Consider recommending urine ketone testing to test for adequate kilocaloric and/or carbohydrate daily consumption if a woman consistently is losing weight, or you suspect that a woman may be knowingly restricting kcalories or carbohydrates to avoid weight gain or avoid possible medication therapies. If urine ketone testing is recommended: Advise patient to test fasting urine sample daily for 7 days. If negative, proceed to bi-weekly testing. If positive, proceed with daily testing until negative. Blood Glucose Monitoring Consider recommending home blood glucose monitoring to assess for optimal glycemic targets. Advise patient to test Four times Daily. Tests should include the Fasting level AND 2 hours after the start of the Breakfast, Lunch, and Dinner meals. According to the ACOG guidelines, optimal glycemic targets: Fasting < 95 mg/dl 2 Hours Postprandial < 120 mg/dl

5 When Medical Nutrition Therapy (MNT) has not resulted in optimal glycemic targets, Medication and/or Insulin therapy should be considered. Oral Agents GLYBURIDE, a second-generation sulfonylurea, has been shown to be a safe and effective adjunct to medical nutrition therapy in the management of GDM. Ensure that there is no allergy to sulfa, otherwise insulin must be used. When recommending Glyburide, patients should start with the lowest daily dose, which is 2.5 mg PO Once Daily; Twice daily if the Fasting glucose level is abnormal in addition to the postprandial levels. The dose should then be titrated in increments of 2.5 mg as needed. The maximum daily dose of Glyburide should not exceed 20 mg. If the patient s glucose levels are not adequately controlled within 2 weeks, then insulin therapy should be considered. METFORMIN, a biguanide, does not appear to be teratogenic, however large, randomized trials have not yet been completed. Some endocrinologists encourage the continuation of Metformin through the first trimester, in women with PCOS and/or Type 2 Diabetes. Consultation with the endocrinologist is recommended.

6 Insulin Therapy Insulin continues to be the treatment of choice in achieving optimal glycemic targets in the management of GDM. Insulin therapy should be recommended for patients treated with Medical Nutrition Therapy when 2 hour postprandial levels exceed 120 mg/dl or Fasting levels exceed 95 mg/dl. Insulin Dosing To Determine TDD (Total Daily Dose): 0.7 units/kg of body weight 1-12 weeks gestation 0.8 units/kg of body weight weeks gestation 0.9 units/kg of body weight weeks gestation 1.0 units/kg of body weight 35 weeks to term Consider starting with 0.5 units/kg of body weight and then titrate as needed. Once the TDD is calculated. Give 50% of the TDD as Basal insulin in two divided doses of NPH insulin. One to be given at Breakfast and the other to be given at Bedtime. The remaining 50% of the calculated TDD should be given in three equally divided Pre-Prandial insulin doses of Lispro (Humalog) insulin.

7 For Example: In a 80 kg woman 80 kg x 0.5 units/kg = 40 units (TDD) 40 % 2 = 20 units Basal = NPH 10 units Twice Daily Pre-prandial = Humalog 6.0 units Before Meals It is recommended that one initiate Basal insulin for the First week. Titrate the dose of NPH insulin by 10-20% every 48 hours until Fasting blood glucose target of 95 mg/dl or less is achieved. If Postprandial levels consistently exceed 120 mg/dl, consider recommending a dose of Lispro (Humalog) insulin 10 minutes before consumption of the meal in the second week of therapy. Titrate the dose of Lispro insulin by 10-20% every 48 hours until Postprandial blood glucose targets of 120 mg/dl are achieved. ANTE-PARTUM TESTING Diet-Controlled If the Gestational Diabetes is diet-controlled, ante-partum testing should include: Bi-weekly Non-stress testing beginning at 40 weeks gestation Biophysical Profile

8 Therapeutic Medications with NO Medical Complications If the Gestational Diabetes is controlled with an oral agent or insulin therapy, with NO medical complications, ante-partum testing should include: Weekly Non-stress testing beginning at 32 weeks gestation Weekly Biophysical Profile Bi-weekly Non-Stress testing and Biophysical Profile beginning at 36 weeks gestation Therapeutic Medications WITH Medical Complications In complicated patients with intrauterine growth restriction, oligohydramnios, preeclampsia, or poorly controlled glucose concentrations, testing may start as early as 26 weeks of gestation and is performed more frequently. Bi-weekly Non-stress testing beginning at 32 weeks gestation Bi-weekly Biophysical Profile POST-PARTUM SCREENING

9 Women with a history of Gestational Diabetes are at increased risk for developing Impaired Glucose Tolerance and Type 2 Diabetes. The American Diabetes Association recommends that a 2 Hour 75 gram OGTT to be coordinated with the 6 week post-partum visit. Criteria for the Diagnosis of IGT and Type 2 Diabetes in the Nonpregnant State Normal Values: Fasting Glucose < 100 mg/dl 2 Hour < 140 mg/dl IGT (Impaired Glucose Tolerance): Fasting glucose mg/dl 2 Hour mg/dl Type 2 Diabetes: Fasting Glucose > 126 mg/dl 2 Hour > 200mg/dl If the initial post-partum OGTT is normal, it is recommended that a 75 gram 2 Hour OGTT be repeated in 1 year, and at a minimum, 3 years thereafter.