MANAGEMENT OF GESTATIONAL DIABETES MELLITUS

CONTENTS Definition Screening Diagnosis Risk assessment Medical Nutrition Therapy Insulin Therapy Intrapartum management Follow up Contraception

DEFINITION Carbohydrate intolerance of variable severity with onset or first recognition during pregnancy.

Pregestational or overt DM Gestational DM

SCREENING

Selective screening ADA NICE IADPSG

Universal screening

DIPSI

RISK ASSESSMENT

LOW RISK Member of an ethnic group with low prevalence of

GDM.No known diabetes in first degree relative.Age < 25yrs.Normal weight before pregnancy.No h/o abnormal glucose metabolism.

Blood glucose screening not routinely required

AVERAGE RISKMember of an ethnic group with high

prevelance of GDM.Diabetes in a first degree relative.Age > 25yrs.Overweight before pregnancy.

Blood glucose testing at 24 – 28 weeks

HIGH RISKMarked obesity.

Strong family history of type II DM.

Previous h/o GDM,impaired glucose metabolism or glycosuria.

Glucose testing as soon as feasible.

SCREENING

ONE STEP SCREENINGCRITERIA FBS

mg/dl1 HRmg/dl

2 HRmg/dl

DIPSI(75 gm)

≥ 140

IADPSG and ADA(75gm)

≥ 92 ≥ 180 ≥ 153

WHO(75 gm)

≥ 125 mg/dl ≥ 140 mg/dl

• TWO STEP PROCEDURECRITERIA FBS

mg/dl

1 HR

mg/dl

2 HR

mg/dl

3 HR

mg/dl

GLUCOSE CHALLENGETEST(50 gms)

.>140mg/dl

CARPENTERAND COUSTON(100 gms)

≥95 ≥180 ≥155 ≥140

OVERT DM

FBS ≥ 126 mg/dl.

RBS ≥ 200 mg/dl.

HbA1c >6.5

Glycemic criteriaCriteria FPG mg/dl 2-hr PG mg/dl

Normal Glucose Tolerance (NTG)

<100 <140

Impaired Fasting Glucose (IFG)

100-125 -

Impaired Glucose Tolerance (IGT)

- 140-199

Diabetes Mellitus (DM) >126 > 200

Fasting plasma glucose or random plasma glucose or HbA1c

Fasting glucose > 126mg/dl

HbA1c > 6.5%

Random glucose > 200mg/dl

Confirm with Fasting glucose or HbA1c

Fasting plasma glucose > 92mg/dl but < 126mg/dl GDM

OVERT DIABETES

2-hour 75g OGTTFasting plasma glucose >92mg/dl 1-hour > 180mg/dl2-hour > 153mg/dl

Fasting glucose > 126mg/dl

One or more values > thresholds

All 3 values < thresholds

OVERT DIABETES

GDM

Normal

24-28 wks

IADPSG 2PHASE

STRATEGY

FBS < 90mg/dl

PPBS < 120 mg/dl

FBS >90mg/dlPPBS >120

mg/dl

Continue on diabetic diet

To do FBS ,PPBSUpto 28wks –mthly

once28-32 wks – once in

2wks> 32 wks upto delivery-

weekly once.

Start insulin

Monitor sugar levelsAccordingly to maintain

FBS≤ 95mg/dl1st hr PPBS ≤ 140mg/dl

2nd hr PPBS ≤ 120

DIABETIC DIET FOR 2WEEKS

GDM

MEDICAL NUTRITION THERAPY• To achieve normoglycemia ,prevent ketosis,provide

adequate weight gain and contribute to fetal well being.

Major nutritional components,Caloric allotmentCHO intakeCaloric distribution

• 3 meals with 3 snacks .

• Total caloric requirement calculated based on BMI.

CALORIE REQUIREMENT• Optimal total daily calorie intake will be between 2000- 2500 Kcal/day.

• CALORIE ALLOTMENT : 45% CHO ,20% Protein, 25- 30% Fats, < 10% saturated fat.

• CALORIE INTAKE :Break fast 25%,Lunch 30%,Dinner 30%

• CHO distribution 10 - 15% : Break fast 20- 30% : lunch 30- 40% : dinner 0- 10% : snacks

EXERCISE• Beneficial for the improvement of glucose

control as a result of enhanced insulin sensitivity due to,

↓ Intra abdominal fat ↑Insulin sensitive glucose transporters (GLUT 4) in muscle. ↑Blood flow to insulin sensitive tissues ↓ free fatty acid level• Brisk walking of 2.52 km in 1hr.

MONITORING GLYCEMIC CONTROL

• If MNT fails to achieve control ,insulin may be initiated.

• Till 28 wks - lab monitoring of both FBS and PPBS once a month.

• After 28 wks - once in 2 wks.• After 32 wks - once a week • High risk pregnancies- frequency of monitoring

may be intensified.

TARGET PLASMA GLUCOSE LEVELS

• FBS ≤ 95 mg/dl.• 1 hr PPBS ≤ 140 mg/dl• 2 hr ≤ 120 mg/ dl• Consistent elevations more than 4 times

over a two week period – insulin should be initiated.

ORAL HYPOGLYCEMIC AGENTS

GLYBURIDE ( micronised form of glybenclamide)• 2nd generation Sulphonylurea• Longer acting• Category B drug• Nonteratogenic• Starting dose is 2.5mg once or twice daily.

METFORMIN• Category B drug

• Biguanides

• Suppress hepatic gluconeogenesis by activation of an enzyme activated protein kinase.

INSULIN THERAPY• Cover the basal needs and elevation in blood

sugar that occurs after meals.

• Correction dose supplement to control sporadic elevations of blood sugar.

• Dose and type of insulin is decided based on the degree of hyperglycemia and obesity.

α αINSULIN RECEPTORS

β βOUTSIDE THECELL

INSIDE THECELL

Phosphorylation

Altered enzyme activity

protein

MECHANISM OF ACTION OF INSULIN

Cell membrane

ANALOGUE CHANGE IN AMINOACID

SEQUENCE TYPE

LISPRO 28-29 proline and lysine are interchanged.

Rapid

ASPART Proline at 28 substituted by aspartic acid

Rapid

GLARGINE Substitution of glycine for aspargine at 21 in α chain and addition of 2 arginine at 30 in β chain.

Long

DETEMIR β chain 30 threonine substituted by myristic acid

Long

TYPE OF INSULIN ONSET (hr) PEAK (hr) DURATION (hr)

Regular 0.5-1.0 2-3 6-8

Lispro 0.25-0.5 1-2 4-6

Aspart 0.25-0.5 1-2 4-6

NPH 1.0 4-8 10-14

Glargine 1.5 - 30

MIXED AND SPLIT DOSE OF INSULIN

Combination of short and intermediate acting insulin in the morning and evening.

2/3rd morning and 1/3rd evening.

Each combination of 1/3rd dose should be

regular and 2/3rd dose should be intermediate

acting insulin.

HOW TO START AN INSULIN?

Every 4th day increase 2 units till 10 units

If FPG remains > 90mg/dl ,6 units before break fast ; 4 units before dinner

Review with blood sugar test; adjust dose further.Total insulin dose /day

can be divided as 2/3rd in the morning and 1/3rd in the evening

Starting dose 4 units before break fast

OBSTETRIC MANAGEMENT

ANTEPARTUM .• Detailed anomaly scan -18 – 20 wks.• Growth scans at 28, 32 and 36 wks.• Non stress test and Biophysical profile.• Doppler – indicated when cases complicated

by preeclampsia and IUGR.

TIMING OF DELIVERY

• Depends upon the presence of maternal or fetal complications or poor glycemic control.

• Good glycemic control with nutritional therapy alone - wait till 40 wks and plan for IOL.

• High risk patients- plan for IOL at 38 weeks

• Elective caesarean section if estimated fetal weight 4.5kgs .

INSULIN MANAGEMENT DURING LABOUR

Usual dose of intermediate acting insulin is given at bed time.

Morning dose of insulin is withheld. Intravenous infusion of normal saline is begun.Once active labour begins or glucose levels decrease

to <70 mg/dl, infusion is changed from saline to 5% Dextrose,delivered at a rate of 100- 150ml/hr.

Short acting insulin is administered by IV infusion at a rate of 1.25U/hr if glucose level exceeds 100 mg/dl.

GDM

FPG or 75 gm, 2 hr OGTT at 6-12 wks postpartum

FBS ≥126 mg/dl2HR ≥ 200 mg/dl

DM

IMPAIRED FASTING GLUCOSE or IGT or BOTH

FBS 110-125 2HR 140-199

NORMALFBS < 110PPBS< 140

REFER FOR DIABETES

MANAGEMENT

• Consider referralWeight loss and physical activity

Counselling as neededConsider metformin if combined impaired

fasting glucose and IGT.Medical nutrition therapy.

Yearly assessment of glycemic status.

Assess glycemic status every 3yrsWeight loss and physical activity.Counselling as

needed.

POSTPARTUM FOLLOW UP

CONTRACEPTION

• Barrier methods

• Oral contraceptives

• IUCD

THANK YOU