GESTATIONAL DIABETES MELLITUS

DR Akinyemi OlaleyeMBBS, FWACS, DGE

ObjectivesReview basic physiology of gestational diabetes

Review fetal and maternal implications Review current recommendations for screening for

GDMReview recommendations from the 5th

International Workshop-Conference on Gestational Diabetes Mellitus

Review use of insulin analogs in pregnancyReview use of oral antihyperglycemic agents in

pregnancy

Definition: metabolic disorder◦ Abnormality in carbohydrate metabolism◦ Relative or absolute insulin lack.

20th century witness remarkable outcome. Before this life expectancy was short Survivors had infertility. Those who got pregnant had disastrous

outcome. MM=30-60%, PM=60%.

Introduction on diabetes and pregnancy

In 1921 banting and best discovered insulin. Fertility was restored MM improved remarkably. PM remained high

◦ Fetal macrosoma, and IUFD were the causes.◦ Early delivery & C/S were the antidote.◦ Late IUFD was still a problem.

1930 White classification.

Introduction cont.

1930 White classification, fetal risk was proportional to severity of mat diabetes,this permitted individualized timing of delivery and perinatal survival =85%.

TODAY, refinement in management has reduced PM to near that of normal pregnancy, except for cong. abnormality.

Introduction cont.

Overt DM, chronic,10% .Type 1or type 2

Gest. DM. 90%. Carbohydrate

intolerance of varying severity with onset or first recognition in preg.

Change in glucose metabolism

Type 2 unmasked in preg.

Classification in pregnancy

Defined as carbohydrate intolerance that begins or is first recognized during pregnancy

Important because it impacts maternal health care both during and after pregnancy

Incidence varies, but most often reported as 5-7% of pregnant women; may be greater in some high-risk populations

Underlying risk factors include increased maternal age, obesity, h/o GDM in prior pregnancy, h/o large babies

OVERVIEW

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12 24 36Gestational Age (weeks)

Normal pregnancy

OVERVIEW

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12 24 36Gestational Age (weeks)

Gestational diabetes

OVERVIEW Cont

Reduced insulin sensitivity. Increased fasting insulin Increased diabetogenic hormones(human

placental lactogen, placental insulinase, cortisol, oestrogens and Progesterone)

Increased insulinase In diabetics, insulin requirement increases

in preg.

Pregnancy &cho metabolism

More difficult to control Proliferative retinopathy may worsen but

the course of background retinopathy and nephropathy does not change,instead it is nephropathy assoc with HT and proteinuria that worsen pregnancy outcome.

No other long term effect of preg on DM.

Pregnancy effects on DM

Spont.abortion Cong. Abnormality Fetal death Macrosomia, Obstructed labour,

instrumental delivery, shoulder dystocia Perinatal mortality Preterm delivery polyhydramnios

Effect of DM on Pregnancy

Infections ( candidiasis, UTI) PIH. Preterm labour.

Effect of DM on preg.

Maternal hyperglycemia

Fetal hyperglycemia

Fetal hyperinsulinemia

Pederson Hypothesis (1952)

OVERVIEW Cont

May be assymptomatic SYMPTOMS & SIGNS: polyuria, polydipsia SCREENING

◦ FBS,2HPP. RBS ◦ 50% glucose oral challenge, 1hr glucose

140mg/dl. 130mg/dl◦ Universal or selective.◦ Timing of screening.

DIAGNOSIS

75g glucose OGTT (WHO) 100g OGTT (ACOG) 3hr monitoring

Diagnosis cont.

Current recommendations for screening for GDM

Do risk assessment at first visit, with no screening for low risk

Low-risk ethnicity (Caucasian, European)Age < 25BMI < 25

No known diabetes in first degree relativeNo h/o glucose intolerance

No h/o obstetric complications usually associated with GDM

4th International Workshop-Conference on Gestational

Diabetes Mellitus, ADA, ACOG

Current recommendations for screening for GDM

High risk patients should be screened as early as possible and repeated at 24-28

weeks if screening negative..Strong family history of diabetes

.Prior history of GDM.Morbid obesity

.Other manifestations of glucose intolerance. glycosuria

4th International Workshop-Conference on Gestational

Diabetes Mellitus, ADA, ACOG

Current recommendations for screening for GDM

Recommended screening is 2-step approach, with 50-g 1-hr GCT followed by 2-hr or 3-hr

100-g OGTTThreshold value for 1-hr GCT is 130 or 140 –

either is acceptableThreshold values for 2-hr OGTT are 95, 180,

155, 140, respectively; 2 values must be abnormal to diagnose GDM

4th International Workshop-Conference on Gestational

Diabetes Mellitus, ADA, ACOG

Current recommendations for screening for GDM

WHO advocates universal screening utilizing a one-step 2-hr 75-g OGTT

Patient is diagnosed with GDM if fasting > 126 or 2-hr > 140

5th International Workshop-Conference on Gestational Diabetes Mellitus did not change

recommendations set forth by 4th International Workshop-Conference on Gestational Diabetes

Mellitus

Measure of glycemia ThresholdFasting glucose > 126 mg/dlA1C > 6.5%Random glucose > 200 mg/dl

To diagnose overt diabetes (preexisting) at any point in pregnancy

Summary for IADPS

International Association of Diabetes and Pregnancy Study

Groups, 2009

Summary

Glucose measure Glucose threshold

FPG 92 mg/dl1-hr plasma glucose 180 mg/dl2-hr plasma glucose 153 mg/dl

Diagnosis of GDM (75g- OGTT)

*one or more of these values must be met or exceeded for diagnosis of GDM

International Association of Diabetes and Pregnancy Study

Groups, 2009

First prenatal visit◦ Measure FBS, A1C, or random glucose on only high-risk

women If results indicate overt diabetes as per Table above, treat and

f/u as for preexisting diabetes If results are not diagnostic of overt diabetes and FPG > 92

but < 126, diagnose as GDM; if FPG < 92, test for GDM at 24-28 weeks

24-28 weeks◦ 2-hr 75-g OGTT after overnight fast on all women not

previously found to have overt diabetes or GDM◦ Overt diabetes if FPG > 126◦ GDM if one or more values equals or exceeds thresholds◦ Normal if all values on OGTT less than thresholds

Summary of screening

International Association of Diabetes and Pregnancy Study

Groups, 2009

Screening/diagnosis◦ WHO endorses universal screening with single

step, arguing that the 2-step process introduces additional barrier to care

◦ Discussions continue around use of fasting, random glucose, or A1C at initial visit, but no consensus at present

Summary of screening for GDM

Pre pregnancy clinic Combined management Early booking and dating More frequent visits Admit for stabilization Dietary control (fasting<105mg/dl)(2hr pp

<120) Mild exercise Preferably use insulin(oral hypoglyceamics) Various insulin regime(Post prandial

surveillance)

Management : holistic approach

Medical management of GDM includes following:◦ Dietary therapy.◦ Exercise◦ Self-monitoring of glucose at home◦ If diet and exercise fail, oral hyperglycemic

agent or insulin metformin safe Short-acting insulin analogs should be standard, and

long-acting analogs not far behind. Counsel on hypoglycemic symptoms

◦ Goal: Euglycemia!!

Management

.Avoid sugar and foods high in sugar

.High fiber diet with correct caloric intake

.30-35 kcal/day with no patient receiving less than 1800 or more than 2800 calories/day

Diet composed of: 1. Carbohydrate 45% 2. Protein 25% 3. Fats 30% If euglycemia is not achieved with diet within 1-2

weeks, use S/C insulin is recommended.Emphasize complex carbohydrates, such as starchy

vegetables (such as potatoes, corn, beans and peas), grains, fruit and other starchy foods .

Dietary management

Physical activity increases insulin receptor sensitivity by counteracting the hormonal changes that accompany pregnancy.

Performing 15 to 20 minutes of armchair exercises daily during routine sedentary activities, such as watching television or reading.

Taking a walk up and down a street. Can help a pregnant woman reduce

hyperglycemia without increasing the risk of inducing uterine contractions.

Exercise

Alpha fetoprotein USS at 20 weeks Value of antenatal testing. Timing& mode of delivery Insulin management in labour. Avoid prolong labour 1-2hourly glucose measurement. Intraprtum monitoring. SHOULDER DYSTOCIA

Management cont

Fetal surveillance with GDM◦ Increased surveillance of fetal well-being

suggested if oral agent or insulin necessary, or abnormal fetal growth evident on ultrasound

◦ Optimal timing of delivery remains uncertain, but would consider delivery by 39 weeks if evidence of poor glucose control and/or abnormal fetal growth noted

◦ Allow usual indications for delivery management if diet controlled with normal growth and well-being

Fetal survaillance.

. Oral hypoglycaemics are contraindicated during early pregnancy, labour and early puerperium as they are not adequate for controlling diabetes, have teratogenic effects and may result in neonatal hypoglycaemia.

- Doses of insulin tend to increase in the first half of pregnancy, then stabilize and finally rise in the last quarter, to be decreased again postpartum.

- Twice daily ( before breakfast and before dinner)

Insulin and oral hypoglyceamics

injections of a combination of short and intermediate acting insulin sufficient otherwise a subcutaneous insulin pump is used.

- Mono component insulin Actrapid" (short acting) and " Mixtard“ (intermediate acting).

- The total first dose of insulin is calculated by starting with a low dose of 20 units combined insulin then increase it according to the blood sugar .

OR according to the patient’s weight as follow: In the first trimester ............patient’s weight x 0.7 In the second trimester.........patient’s weight x 0.8 In the third trimester............patient’s weight x 0.9

Insulin therapy

In higher doses, 2/3 the dose is given in the morning with the same ratio and 1/3 the dose is given in the evening in a ratio 1:1.

Day of delivery, reduce insulin dosage by 25% and avoid intermediate acting or

5% glucose infusion in a rate of 125 ml/hour + short acting insulin 1-2 units/hour.

MACROSOMIA : early feeding, RBS, HB, b1b2.

RDS Hypoglycaemia Hypocalaemia Hyperbilirubin Polycytaemia Perinatal mortality=2-4%( cong abn,unexp

IUFD) cardiac hypertrophy. 1-3% inheritance.

NEONATE

◦ Assess fasting and/or 2-hr PP in first day or two after delivery – no further treatment necessary if normal (majority of GDM)

◦ If fasting and/or 2-hr PP abnormal, continue oral agent or insulin

◦ Screen for Type 2 diabetes at 6-week postpartum visit

◦ Counsel patients regarding dietary and behavioral changes necessary to minimize risk of developing overt diabetes later in life.

◦ Contraception.

Postpartum management

Metabolic assessment after GDM

Time Test PurposePost-delivery (1-3 d) Fasting or random glucose Detect persistent, overt

diabetesPostpartum visit 75-g 2-h OGTT PP classification of glucose

metabolism per ADA1 year postpatum 75-g 2-h OGTT Assess glucose

metabolismAnnually Fasting plasma glucose Assess glucose

metabolismTri-annually 75-g 2-h OGTT Assess glucose

metabolismPrepregnancy 75-g 2-h OGTT Assess glucose

metabolism

5th Annual Workshop-Conference on GDM

Gestational Diabetes should be considered a pre-diabetes condition

Women with gestational diabetes have a 7-fold future risk of type 2 diabetes vs.women with normoglycemic pregnancy

CONCLUSION

Lancet, 2009, 373(9677): 1773-9

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