Gestational Diabetes Update

1. May 22, 2009 Gestational Diabetes Update Leigh Caplan RN CDE Marsha Feldt RD CDE SUNDEC - Diabetes Education Centre

2. Learning Objectives • Review physiology of pregnancy and gestational diabetes • Review CDA clinical practice guidelines for diagnosis and management of gestational diabetes • Highlight nutrition therapy approaches • Discuss role of hospital based gestational diabetes programs • Discuss post partum considerations for diabetes risk and prevention

3. Case study: Sue comes to see you for nutrition counselling • 32 years old, BMI 25 • family history of type 2 • G1P0 26 wks gestation • Informs you she just received the diagnosis of gestational diabetes • GTT results - 5.1, 10.7, 9.1 What do you do?

4. Gestational Diabetes • Definition: Hyperglycemia with onset or first recognition during Pregnancy • Prevalence 3.7% in non-aboriginal 8-18% in aboriginal populations CDA CPG 2008

5. Physiology in Late Pregnancy • Characterized by accelerated growth of the fetus • A rise in blood levels of several diabetogenic hormones • Food ingestion results in higher and more prolonged plasma glucose concentration

6. Physiology in Late Pregnancy • Maternal insulin and glucagon do not cross the placenta • During late pregnancy a women’s basal insulin levels are higher than non-gravid levels • Food ingestion results in a twofold to threefold increase in insulin secretion (Franz, M.J., 2001)

7. Physiology of GDM • Gestational hormones induce insulin resistance • Inadequate insulin reserve and hyperglycemia ensues

8. Gestational Diabetes Fetal Risks • Macrosomia - shoulder dystocia and related complications • Jaundice • Hypoglycemia • No increase in congenital anomalies Exposure to GDM in utero • LGA children or those born to obese mother have a 7% risk of developing IGT at 7-11 yrs age • Breastfeeding may lower risk CDA CPG 2008

9. Gestational Diabetes Maternal Risks • C-section • Pre-eclampsia • Recurrence risk of GDM is 30-50% • 30-60% lifetime risk in developing IFG, IGT or type 2 diabetes CDA CPG 2008

10. GDM Screening • All women should be screened for GDM between 24-28 weeks • vs. risk factor based approach which can miss up to ½ the cases of GDM • Women with multiple risk factors should be screened in the first trimester

11. Risk Factors: for first trimester screening • > 35 yrs • BMI > 30 • Previous diagnosis of GDM • Delivery of a mascrosomic baby • Member of a high-risk population • (Aboriginal, Hispanic, South Asian, Asian, African) • Acanthosis nigricans • Corticosteroid use • PCOS

12. Diagnosis of Gestational Diabetes Gestational Diabetes Screen (GDS) 1 hr after 50g load of glucose

13. Diagnosis of Gestational Diabetes 75 g OGTT • GDM = 2 or more values greater than or equal to • IGT = single abnormal value

14. Management of Gestational Diabetes • Strive to achieve glycemic targets • Receive nutrition counselling from an Registered Dietitian • Encourage physical activity • Avoid ketosis • If BG targets are not reached within 2 weeks then insulin therapy should be started

15. Target Blood Glucose Values for GDM • Fasting/Pre-prandial: 3.8 – 5.2 mmol/L • 1 hour 5.5 - 7.7 mmol/L • 2 hour 5.0 - 6.6 mmol/L

16. Nutrition Therapy as treatment for GDM • A tool to achieve appropriate nutrition and glycemic goals of pregnancy • to normalize fetal growth and birth weight

17. Medical Nutrition Therapy for GDM Definition: A carbohydrate controlled meal plan with adequate nutrition for appropriate weight gain, normoglycemia, and the absence of ketones

18. Clinical Outcomes • Achieve and maintain normoglycemia • Promote adequate calories for wt gain in absence of ketones • Consume food providing adequate nutrients for maternal and fetal health

19. GDM Nutrition Controversies • What is a healthy weight gain for an obese woman with GDM? • How far to manipulate energy intake? • Does the balance of carbohydrate and fat matter?

20. Excess Weight Gain • May increase incidence of GDM in future pregnancy Obese women have larger babies • More likely to develop macrosomia if gain >25lb • More likely to develop macrosomia with high post prandial BG levels

21. Calorie Restricted Diets • Avoid severe restriction - <1500 kcal not recommended • Avoid ketones • 33% calorie restriction slowed wt gain and improved BG – 1800 kcal

22. Role of Carbohydrate • Carbohydrate can be modified to control postprandial glucose elevations • High fiber not associated with lower glucose levels in GDM • Lower carb intake (<42%) associated with; less insulin; less LGA • Postprandial correlated with %CHO at meal; breakfast less tolerance

23. Emphasis for GDM • Healthy Eating following CFG appropriate for adequate weight gain • DRI= minimum 175 g CHO/day • Spacing of CHO into 3 meals & 2 to 4 snacks • Smaller amounts of CHO at breakfast* • Evening snack is important to prevent ketosis overnight • Encourage activity as tolerated

24. Carbohydrate Counting with “Beyond the Basics” • Canadian Diabetes Association meal planning guide • Based on Canada’s food guide groups • Each food group outlines portion sizes of various foods • Each carbohydrate choice (grains/starch, fruit, milk) = 15 grams carbohydrate

25. Grains – 8-10 choices Fruit – 2-3 choices Milk – 3-4 choices

26. Dietary Fat in GDM • up to 40% of total energy intake during pregnancy • choose food source which are lower in saturated and transfats

27. Artificial Sweeteners When used within ADI • Aspartame – does not cross placenta; no adverse effects • Sucralose (splenda) – acceptable • Acesulfame potassium – acceptable • Saccharin – crosses placenta; not acceptable • Cyclamates – not acceptable

28. Back to Sue 3 weeks later • Trying to work with meal plan • Weight has been stable for 3 weeks • Blood glucose readings: • Fasting 5.0 to 5.7 • 2 hours pc breakfast 4.6 to 5.3 • 2 hours pc lunch 5.7 to 6.5 • 2 hours pc dinner 7.2 to 7.9 What do you discuss with Sue?

29. Insulin ? or !

30. Purpose of Insulin • To achieve plasma glucose control nearly identical to those observed in women without diabetes • Must be individualized • Insulin requirements will change with various stages of gestation (ADA. Medical Management of Pregnancy Complicated by Diabetes., 2000)

31. Types of Insulin Approved in pregnancy • Fast acting: Humalog , NovoRapid • Short acting: Regular/R • Intermediate acting: NPH/N • Detemir can be used if woman unable to tolerate NPH ( Ongoing study to evaluate use in pregnancy) • Glargine – avoid use

32. Devices for Insulin Delivery

33. Considerations for Adjusting Insulin • Look for patterns in blood glucose readings • Adjust for hypoglycemia first • Then adjust for high blood glucose

34. Can oral hypoglycemia agents be used to treat GDM? • Glyburide • Does not cross the placenta • Controlled BG in 80% of women • Women with high FBG less likely to respond to Glyburide • More adverse perinatal outcomes compared to insulin • Not approved in Canada • use is considered off-label and requires appropriate discussions of risks with patient CDA CPG 2008

35. Metformin • alone or with insulin was not associated with increased perinatal complications compared with insulin • Less severe hypoglycemia in neonates • Does cross the placenta – long term study MiG TOFU ongoing • Not approved in Canada • use is considered off-label and requires appropriate discussions of risks with patient NEJM, 2008

36. Postpartum Physiology: Once the placenta is delivered: • Hormones clear from circulation • They will be monitored in hospital if blood glucose remains elevated may require medications

37. Postpartum Focus: • Encourage follow up with health care provider to have • OGTT (6 weeks to 6 months 75 g OGTT) • weight management, • postpartum visit with a registered dietitian • Encourage breastfeeding • Monitoring occasionally with meter • Future pregnancy

38. Breastfeeding and DM meds • Both metformin and glyburide/glipizide are found at low concentrations (or not at all) in breast milk • Hale et al, Diabetologia 2002 • Feig et al, Diabetes Care 2005 • Can be considered however, more long-term studies needed

39. SUNDEC– Diabetes Education Centre(416) 480-4805 • Multidisciplinary team of health professionals ( RN, RD) • Self referral • Individual counselling • Group education classes • Type 2, Pre-diabetes, Diabetes Prevention and Seniors programs

40. Case 2Justine Justine was diagnosed with gestational diabetes at 20 weeks, • pre-preg BMI = 28.7, GTT results were: 6.2, 10.2, 9.8 She is now at 25 weeks • FBS 6.1 – 7.4 • 3 meals and 1 -2 snacks. • Diet history: Oatmeal at breakfast, lunch and dinner consist of aprox. ½ cup rice, lots of vegetables and meat, in the afternoon a piece of fruit, 2 cups of milk at bed • What would you do?

41. www.diabetes.ca

42. Resources and References Canadian Diabetes Association: www.diabetes.ca -Recommendations for Nutrition Best Practice in the Management of GDM -2003 Canadian Diabetes Association Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada Nutrition for a Healthy Pregnancy: National Guidelines for the Child Bearing Years Healthy Eating is in Store for you: www.healthyeatingisinstore.ca