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

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

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?

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

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

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)

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

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 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 Gestational Diabetes

GDM Screening All women should be screened for GDM between 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

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

Diagnosis of Gestational Diabetes Gestational Diabetes Screen (GDS) 1 hr after 50g load of glucose Value75 g OGTT indicated <7.8 mmol/Lno mmol/Lyes > 10.3 mmol/LNo - GDM

Diagnosis of Gestational Diabetes 75 g OGTT GDM = 2 or more values greater than or equal to IGT = single abnormal value Fasting> 5.3 mmol/L 1 hr> 10.6 mmol/L 2 hr> 8.9 mmol/L

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

Target Blood Glucose Values for GDM Fasting/Pre-prandial: 3.8 – 5.2mmol/L 1 hour mmol/L 2 hour mmol/L

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

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

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

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?

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

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

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

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

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

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

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

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

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?

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)

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

Devices for Insulin Delivery

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

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

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

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

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

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

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

Case 2 Justine 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 – 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?

Resources and References Canadian Diabetes Association: -Recommendations for Nutrition Best Practice in the Management of GDM 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: