Management of Gestational

Diabetes mellitusKapila Gunawardana

Definition

Gestational diabetes is commonly defined as glucose intolerance first recognized during pregnancy

Glucose metabolism & pregnancy

Due to placental production of anti-

insulin hormones, there is a state of

insulin resistance

hPL , cotisol ,prolactin, GH ,estrogen and

progesterone

Compare to non pregnant women

Low FBS with high PPBS

Low renal threshold for glucose & ↑ GFR

leads to glycosuria

Increased production of insulin and high

fasting insulin may lead to functional failure

of the Pancreas

Risk factors

1. Obesity

2. Previous history of GDM

3. Family history of diabetes

4. Racial origin

Asian and African-Caribbean

5. Maternal age more than 25

6. Previous macrosomic baby

7. Polycystic ovary syndrome

8. Multiple pregnancy

Screening & Diagnoses

75 g OGTT new diagnostics values

NICE/WHO IADPSG RECOMMENDED

mmol/l

mg/l

mmol/l

mg/l

mmol/l

mg/l

FBS ≥7.0

126 ≥5.1

91.8

≥5.1 91.8

1Hr ≥10.0

180 ≥10.0

180

2Hr ≥7.8

140.4

≥8.5

153 ≥8.5 153

75g OGTT Low risk group at 24 – 28 weekHigh risk group at booking if normal again 24 – 28 weekOne abnormal value enough for diagnosis

Maternal complications

Cesarean section/Operative

deliveries/Trauma

Pre-eclampsia

Psychological morbidity.

Recurrence risk of GDM is

30-50%

30-60% lifetime risk in

developing , IGT or type 2

diabetes

Fetal complications

The accepted pathological mechanism by which GDM leads to

complications is known as the Pedersen hypothesis

Macrosomia

shoulder dystocia, birth trauma

and related complications

Unexplained IUD

Polyhydramnios and PPROM or PROM

Metabolic complications

Hypoglycemia, hypothermia,

Ca2+, Mg2+, Polycythemia & Jaundice

Rationale of treatment

oIts' treatment is also controversial.

oNo clear guidelines and universally

accepted treatment plans available.

oHowever randomized trials show

benefits

o in treating the GDM

o The Australian Carbohydrate Intolerance Study

(ACHOIS) was published in 2005

o National Institute of Child Health and Human

development (NICHD) trial – USA 2009

Treatment plan

Multi disciplinary approach

Close monitoring & treatment

of GDM are very important for

mother & baby

Lifestyle modification

Pharmacotherapy

Multi-disciplinary approach

Obstetrician

Endocrinologist

Physician

Dietician

Paediatrician

Diabetic nurse.

MonitoringFBS 1hr PPBS 2hr PPBS

mmol/l

mg/l

mmol/l

mg/l

mmol/l

mg/l

NICE UK 3.5-5.9

63-106

7.8 140

ACOG 5.3 95 7.2 130

6.7 120

5th international

GDM workshop(2007)

5.3 95 7.8 140

6.7 120

You may have to test four times a day:1. Fasting

2. 1 or 2 hours after breakfast3. 1 or 2 hours after lunch4. 1 or 2 hours after dinner

Lifestyle modificationDietary recommendations

Dietary pattern & calorie distributions

Breakfast- 10%

Lunch- 30%

Dinner- 30%

Bed time snack- 30%

Calorie -2000-2200kcal/day

Normal weight:30kcal/kg

Lean 35kcal/kg

Obese:25kcal/kg)

Composition:

Carbohydrate - 40-50% complex, high fiber;

Protein - 20%;

Fat - 30-40%(<10%saturated)

A healthy diet is one that includes a balance of foods from all the food groups, giving the nutrients, vitamins, and minerals necessary for a healthy pregnancy

Lifestyle modification

Exercise Women with gestational

diabetes often need regular, moderate physical activity to help control their blood sugar levels by allowing insulin to work better.

Walking Prenatal aerobics classes Swimming

However, a consultation and approval by a health care provider is needed before beginning any physical activity during pregnancy.

Pharmacotherapy-Insulin

•When diet and lifestyle modifications fail to control blood glucose within 1 to 2 weeks then pharmacological treatment should be commenced.

Pharmacotherapy-Insulin regime

RCT found basal bolus regime gives better control compared to twice daily regime.

Pharmacotherapy -OHA

Metformin-(MIG Trial Metfor. Vs Insulin in GDM) & Glibenclamide (both drugs safe in pregnancy, both cross the placenta but no short term and intermediate fetal adverse outcomes.)

30-45% of patients in OHA need supplementary insulin to control their blood sugar.

Antenatal care

Review every 1-2 weeks, more frequently if complication ensue.

Anomaly scan at 18-20 weeks

Serial ultrasound from 28 weeks to detect fetal macrosomia.

Monitoring of glucose every 1-2 week

Frequency & timing of antenatal fetal monitoring is controversial . Complicated GDM needs early antenatal fetal monitoring as early as 32 wks.

Can give antenatal steroids for fetal lung maturation and may need additional insulin

Antenatal care

Timing of delivery is controversial and if uncomplicated can go up to 40wks. However, decision should be made according to the available informations.

Mode of delivery will depend on the clinical as well as ultrasonographic evidence available.

Diabetes should not be a contraindication for VBAC

Intra natal care

GDM requiring pharmacological therapy are best managed intravenous insulin drips and glucose monitoring hourly .

Others need only blood glucose monitoring during labour.

Target blood sugar range 4-7mmol per l(72-126mg per l)

Continuous fetal heart monitoring is advisable during labour.

Postpartum care

Exclude persisting hyperglycaemia before discharge ( FBS or PPBS)

Breast feeding should be encouraged & neonate blood sugar to be check 2–4 hours after birth.

Lifestyle advice (including weight control, diet and exercise).

OGTT at the 6 week.

Every three year thereafter.

Early screening for diabetes in future pregnancies.

Contraception & preconception care.