Gestational Diabetes UpdateLeigh Caplan RN CDEMarsha Feldt RD CDESUNDEC - Diabetes Education Centre

May 22, 2009

Learning ObjectivesReview physiology of pregnancy and gestational diabetesReview CDA clinical practice guidelines for diagnosis and management of gestational diabetesHighlight nutrition therapy approachesDiscuss role of hospital based gestational diabetes programsDiscuss post partum considerations for diabetes risk and prevention

Case study:Sue comes to see you for nutrition counselling32 years old, BMI 25family history of type 2G1P0 26 wks gestationInforms you she just received the diagnosis of gestational diabetesGTT 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 populationsCDA CPG 2008Gestational 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 PregnancyMaternal insulin and glucagon do not cross the placenta

During late pregnancy a womens 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 GDMGestational hormones induce insulin resistance

Inadequate insulin reserve and hyperglycemia ensues

Fetal Risks Macrosomia - shoulder dystocia and related complications JaundiceHypoglycemiaNo 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 2008Gestational Diabetes

Maternal RisksC-sectionPre-eclampsiaRecurrence risk of GDM is 30-50%30-60% lifetime risk in developing IFG, IGT or type 2 diabetesCDA CPG 2008Gestational Diabetes

GDM ScreeningAll women should be screened for GDM between 24-28 weeksvs. risk factor based approach which can miss up to the cases of GDM

Women with multiple risk factors should be screened in the first trimester

Risk Factors: for first trimester screening> 35 yrsBMI > 30 Previous diagnosis of GDMDelivery of a mascrosomic babyMember of a high-risk population (Aboriginal, Hispanic, South Asian, Asian, African)Acanthosis nigricansCorticosteroid usePCOS

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

Value75 g OGTT indicated 10.3 mmol/LNo - GDM

Diagnosis of Gestational Diabetes 75 g OGTT

GDM = 2 or more values greater than or equal toIGT = single abnormal value

Fasting> 5.3 mmol/L1 hr> 10.6 mmol/L2 hr> 8.9 mmol/L

Management of Gestational DiabetesStrive to achieve glycemic targetsReceive nutrition counselling from an Registered DietitianEncourage physical activity Avoid ketosisIf 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 5.5 - 7.7mmol/L

2 hour 5.0 - 6.6mmol/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 OutcomesAchieve and maintain normoglycemiaPromote adequate calories for wt gain in absence of ketonesConsume food providing adequate nutrients for maternal and fetal health

GDM Nutrition ControversiesWhat 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 GainMay increase incidence of GDM in future pregnancy

Obese women have larger babiesMore likely to develop macrosomia if gain >25lbMore likely to develop macrosomia with high post prandial BG levels

Calorie Restricted DietsAvoid severe restriction -

Role of CarbohydrateCarbohydrate can be modified to control postprandial glucose elevations High fiber not associated with lower glucose levels in GDMLower carb intake (

Emphasis for GDMHealthy Eating following CFG appropriate for adequate weight gainDRI= minimum 175 g CHO/daySpacing 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 Canadas 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 GDMup to 40% of total energy intake during pregnancychoose food source which are lower in saturated and transfats

Artificial SweetenersWhen used within ADIAspartame does not cross placenta; no adverse effectsSucralose (splenda) acceptableAcesulfame potassium acceptable

Saccharin crosses placenta; not acceptableCyclamates not acceptable

Back to Sue 3 weeks laterTrying to work with meal planWeight has been stable for 3 weeksBlood glucose readings:Fasting 5.0 to 5.72 hours pc breakfast 4.6 to 5.32 hours pc lunch 5.7 to 6.52 hours pc dinner 7.2 to 7.9What do you discuss with Sue?

Purpose of InsulinTo achieve plasma glucose control nearly identical to those observed in women without diabetesMust 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 pregnancyFast acting: Humalog , NovoRapidShort acting: Regular/RIntermediate acting: NPH/NDetemir 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?GlyburideDoes not cross the placentaControlled BG in 80% of womenWomen with high FBG less likely to respond to GlyburideMore adverse perinatal outcomes compared to insulinNot approved in Canadause is considered off-label and requires appropriate discussions of risks with patientCDA CPG 2008

Metformin alone or with insulin was not associated with increased perinatal complications compared with insulinLess severe hypoglycemia in neonatesDoes cross the placenta long term study MiG TOFU ongoing

Not approved in Canadause is considered off-label and requires appropriate discussions of risks with patientNEJM, 2008

Postpartum Physiology:

Once the placenta is delivered:Hormones clear from circulationThey 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 dietitianEncourage breastfeedingMonitoring occasionally with meterFuture pregnancy

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

SUNDEC Diabetes Education Centre(416) 480-4805

Multidisciplinary team of health professionals ( RN, RD)Self referralIndividual counsellingGroup education classesType 2, Pre-diabetes, Diabetes Prevention and Seniors programs

Case 2JustineJustine 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 7.43 meals and 1 -2 snacks. Diet history: Oatmeal at breakfast, lunch and dinner consist of aprox. cup rice, lots of vegetables and meat, in the afternoon a piece of fruit, 2 cups of milk at bedWhat would you do?

www.diabetes.ca

Resources and ReferencesCanadian 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

***Ask patient what they know about gestational diabetes, what they heard read, let them tell their story (guilt)***Positive spin on having gestational dm***Cumulative incidence increases markedly in the first 5 years and then more slowly over 10 years.*****Monitoring 4 times per day**Diet only is primary therapy for 40-80% of womenLimited evidence-based information to guide specific nutrition recommendationsCarbohydrate focus not a calorie focus, glucose control and appropriate weight gainIt is important the women understands what to do with her specific food situation*

What are the blood glucose targetsDefined clinical indicators for addition of insulin*Advocate for use of self-monitoring of blood glucose to assist with achieving good blood glucose control and in assessing the adequacy of the diet -may need to check overnight ketones to ensure adequate intakeand food intakeWeight gain parameters vary and are based on pre-preg BMINutrient requirements are similar to women without DM such that the document for Nutrition for a Healthy Pregnancy: National Guidelines for the Child bearing years can be used.Visit schedule

*Goal= promote nutrition necessary for maternal & fetal health, healthy wt gain, maintenance of normoglycemia and absence of ketones - Evidence for the optimal diet is lacking !Ltd data on minimal wt gain that is safe (only observational studies re: wt gain & pregnancy NOT randomized controlled studies)Obese women are more prone to having LGA infants- regardless (increases with increasing maternal wt gains- macrosomia increases with wt gain >25 lbs)With morbid obese- risk of SGA is not increased even if no wt gain occurs (wt neutral = ? Ok)1st trimester is more predictive of infant weight - 3rd trimester is least predectiveIOM guidelines are generally accepted (based on pre-preg BMI)Several studies have shown that energy restricted diets in obese women with GDM (