Diabetes in Pregnancy

L.Sekhavat MD

Diabetes in PregnancyGestational Diabetes

Pre-gestational diabetes (overt)Insulin dependent (type1)Non-insulin dependent (type 2)

Definition

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy

Diabetes in pregnancy

Pre-existing diabetes Gestational diabetes

Pre-existing diabetesIDDM (Type1)

NIDDM(Type2) True GDM

Gestational diabetes typically is 3rd trimester disorder

Overt diabetes is 1st trimester

Some general character istic of type1 and type 2 diabetes

Characteristic type1 type2 genetic ch 6 unknownAge at onset <40 >40Habitus normal to wasted obesePlasma insullin low to absent normal to highInsullin therapy responsive R/resistant

Classification of diabetesClass onset FBS 2hpp therapyA1 gestational <90 <120 dietA2 gestational >90 >120 insullinClass age of onset duration V diseasesB >20 10-19 noneC 10-19 10-19 noneD <10 >20 B retionopathyF any any nephropathyR any any P retionopathyH any any heart D

Normal Maternal Glucose Regulation

Tendency for maternal hypoglycemia between meals - fetal demandIncreasing tissue insulin resistance during pregnancy

↑ Diabetogenic placental steroid↑ Estrogen, Progesterone↑HPL

Increased insulin production (= 30% mean)

Fetalhyperinsulinemia

Fetus

Fetal pancreas stimulated

MotherPl

acen

ta

Insulin

Maternal hyperglycemia

The Impact of Maternal Hyperglycemia Dur ing Pregnancy

Maternal HyperglycemiaCauses fetal hyperglycemiaLeading to fetal hyperinsulinemiaFetal hyperinsulinemia - even short periods (1-2 hours) lead to detrimental consequences in:

fetal growthfetal well-being

Fetal Hyper insulinemiaPromotes storage of excess nutrients -macrosomniaIncreased catabolism of excess nutrients -energy usage and low fetal oxygen storageEpisodic fetal hypoxiaIncreased catecholamines causing:

hypertensioncardiac hypertrophy

Increased Erythropoietin:Hyperbilirubinaemia

Diagnosis:

Glucosuria is common in pregnancy (Renal glycosuria)

so not diagnostic.

Fasting and 2 hours postprandialvenous plasma sugar dur ing pregnancy.

Diabetic>120 mg/ dl.>95 mg/dl

Not diabetic< 120mg/ dl.<95 mg/dl

Result2h postprandialFasting

Risk Factors:> 25 years oldPrevious macrosomnic infantUnexplained fetal demisePrevious GDMFamily hx - GDM/NIDDMObesity > 90KgSmoking

50-g oral glucose challengeThe screening test for GDM, a 50-g oral

glucose challenge, may be performed in the fasting or fed state. Sensitivity is improved if the test is performed in the fasting state .

A plasma value above 130-140 mg/dl one hour after is commonly used as a threshold for performing a 3-hour OGTT. If initial screening is negative, repeat

testing is per formed at 24 to 28 weeks.

3 hour Oral glucose tolerance test

Prerequisites:Normal diet for 3 days before the test.No diuretics 10 days before.At least 10 hours fast.Test is done in the morning at rest.

Giving 100 gm (75 gm by other authors) glucose in 250 ml water orally

Criter ia for glucose tolerance testThe maximum blood glucose values during

pregnancy:fasting 95 mg/ dl, one hour 180 mg/dl,2 hours 155 mg/dl, 3 hours 140 mg/dl.

If any 2 or more of these values are elevated, the patient is considered to have an impaired glucose tolerance test.

Pregnancy Complication

HydramniosSpontaneous abortionsCongenital malformationsMacrosomiaDiabetic ketoacidosisNeonatal metabolic complications

Macrosomia -Pathogenesis

Macrosomnia(Greater than 90 precentile, 4200 grammes)

Increased birth traumaMacrosomnia as a child and glucose intolerance in adulthood

Congenital AnomaliesCardiac defects 8.5%CNS defects 5.3%

AnencephaSpina Bifida

All Anomalies 18.4%Specially over t diabetes The most r isk is HgA1c >10

Maternal ComplicationsPre-eclampsiaDiabetic ketoacidosisMaternal hypoglycemiaMaternal traumaHigher C/S rateRetinal disease/renal disease not affected significantly by pregnancy

Per inatal Mor tality/Morbidity

MiscarriageIUGRMacrosomiaBirth Injury

Neonatal Morbidity and Mor tality

Neonatal hypoglycemiaPolycythemiaHyperbillirubinemiaHypertrophic and congestive cardiomyopathyARDSDevelopment of obesity and diabetes in childhood

Treatment of Gestational DiabetesDiet and exerciseGlucose monitoringInsulin if necessary (Hypoglycemic agents?)2-weekly visits to Diabetic service/antenatal service & Growth Monitoring (scan)Delivery based on obstetric issues

Diet Therapy

Goals of an Effective diet: NormoglycemiaAdequate weight gainGood fetal health

Medical nutrition therapy should include the provision of adequate calories and nutrients to meet the needs of pregnancy

( Diet: 50% carb, 20% prot, 30% fat)

Exercise Therapyexercise diminishes peripheral resistance to insulin cardiovascular conditioning increase affinity and receptor bindingReduction in both fasting and postprandial glucose

may decrease need for other therapies in Gestational Diabetes

insulin therapy is recommended when medical nutrition therapy fails to maintain self-monitored glucose at the following levels:

Fasting blood glucose <95 mg/dLor1-hour postprandial blood glucose <140

mg/dL or2-hour postprandial blood glucose <120

mg/dL

Insulin therapy

The total first dose of insulin is calculated according to the patient’s weight as follow:

In the first trimester .......... weight x 0.7In the second trimester........ weight x 0.8In the third trimester........... weight x 0.9

Insulin therapy

Insulin Therapy (dosage)Divide the injections:

60% Regular insulin30% before breakfast15% before lunch15% before dinner

40% NPH30% before breakfast10% before bed

One study demonstrated that the 4 injection a day as compared to 2 injections a day improved glycemic control and perinatal outcome

ManagementTest AFP at 16-20 weeksAntenatal visits – 2 weekly after 24 weeksNST weekly (starting at 28-30 wks)Anomaly scan at 16- 20-weeks andGrowth scans from 26-28 weeksDelivery

Around term if insulin dependent unless complicationsDiet only control as normal antenatal patients

When antepartum testing suggests

fetal compromise, delivery must be

considered.

Intrapar tum managementIV fluids (5% dextrose) + insulinHourly glucose monitoringManage labor as normal

The need of insulin typically decreased after delivery so:Avoid of NPH and used Regular insulin

Management - Postpar tumUse pre pregnancy insulin levels when on diet and monitor. Breast feeding?GDM - long term risk of NIDDMContraception

After delivery nearly all postpartum women will become normoglycemic 1/3 to 2/3 will have recurrent GDM in subsequent pregnancies

Over than 50% of gestational diabeteslead to overt diabetes