Gestational diabetes

Question 1

What is gestational diabetes?

Answer 1

Any degree of glucose intolerance with onset or first recognition during pregnancy
Transient resistance occurs in pregnancy, an effect of the high concentration of pregnancy hormones which act as antagonists to insulin action

Question 2

What is happening to the incidence of gestational diabetes?

Answer 2

Increasing

Question 3

What is the incidence of gestational diabetes?

Answer 3

1 in 5

Question 4

When does gestational diabetes occur?

Answer 4

When the body is unable to produce enough insulin to meet the needs of the pregnancy

Question 5

What happens to insulin resistance during pregnancy

Answer 5

Progressive insulin resistance - higher volume of insulin is needed in response to a normal level of blood glucose
Insulin requirements increase by 30% during pregnancy

Question 6

List the risk factors for poor pancreatic reserve

Answer 6

BMI>30 
Asian ethnicity 
Previous gestational diabetes
1st degree relative with diabetes
Polycystic ovarian syndrome
Previous macrocosmic baby >4.5kg

Question 7

List the clinical symptoms of gestational diabetes

Answer 7

Asymptomatic
Polyuria
Polydipsia
Fatigue

Question 8

List the foetal complications of gestational diabetes

Answer 8

Macrosomia - shoulder dystocia, obstructed/delayed labour, higher rates of instrumental delivery 
Organomegaly - cardiomegaly 
Erythropoiesis - polycythaemia
Polyhydramnios
Increased rates of pre-term delivery

Question 9

What is insulin

Answer 9

A hormone that has similar structure to growth promotors

Question 10

How does gestational diabetes cause foetal hyperinsulinemia

Answer 10

Glucose is transported across the placenta but insulin is not
Causes foetal hyperglycaemia and to compensate the foetus increases its own insulin levels to compensate

Question 11

What is the foetus at risk of after delivery and why?

Answer 11

Hypoglycaemia - high insulin levels but no more glucose from the mother

Transient tachypnoea of the newborn - high insulin causes a reduction in pulmonary phospholipids which in turn decreases foetal surfactant production. Reduces the surface tension in alveoli

Question 12

What is important to prevent/help with hypoglycaemia after birth in the baby?

Answer 12

Regular feeding

Question 13

What investigations are there for gestational diabetes

Answer 13

Oral glucose tolerance test

Question 14

Describe the oral glucose tolerance test

Answer 14

Fasting pladma glucose is measured, then a 75g glucose drink is given with a repeat plasma glucose measurement after 2hrs

Question 15

How is GDM diagnosed?

Answer 15

If fasting glucose >5.6mmol/L or 2hr post prandial glucose >7.8mmol/L

Question 16

When is OGTT offered in the UK?

Answer 16

Booking - if previous gestational diabetes
24-28 weeks - if risk factors present
At any point during pregnancy - if +2 glycosuria on one occasion or ?1 on 2 occasions

Question 17

Describe the management of gestational diabetes

Answer 17

Lifestyle - diet and exercise
4x daily cap glucose measurements
Medical - metformin, glibenclamide (if metformin not tolerated)
Insulin - if fasting glucose >7

Consultant led care

Growth scans

Aim to deliver 37-38 weeks

Question 18

What is the main side effect of metformin?

Answer 18

GI disturbance

Question 19

Describe the post-natal care of gestational diabetes

Answer 19

Anti-diabetic medication stopped immediately after delivery

Check blood glucose before discharge
6-13 weeks post partum - fasting blood glucose test - increased risk of developing diabetes in the future

In subsequent pregnancies, OGTT offered at booking and 24-28 weeks gestation

Question 20

What is diabetes?

Answer 20

Metabolic disorder characterised by raised plasma concentrations of glucose, amino acids and fats

Question 21

Name and describe the two types of diabetes

Answer 21

T1DM - reduction in production and release of insulin from the pancreas
T2DM -reduction in the sensitivity to insulin in the body’s organs and tissues

Question 22

For women who already have pre-existing diabetes what should the sugar and HBA1c levels be before pregnancy?

Answer 22

Aim for HBA1C <48mmol/mol
Fasting <5mmol/l
1 hour post-prandial <7.0mmol/L

Question 23

What percentage risk of congenital abnormality does a HBA1C >86mmol/mol indicate?

Answer 23

25%

Question 24

What measures should be taken before pregnancy in a patient with pre-exisiting diabetes?

Answer 24

Ready, set, go

• Review medication - stop statins/ACEi
• renal and retinal assessment every trimester
• Folate prescription 3months in advance - 5mg OD - pre and for 1st trimester
• HBA1C aim <48mmol/mol - optimise glucose control
• Aspirin 150mg - decrease risk of PET
• Serial growth scans
• Foetal echo at 18weeks
• IOL 37-38+6 weeks

Question 25

What are the maternal risks from pre-existing diabetes?

Answer 25

Hypos
Deterioration of retinal/renal health 
Infection
Pre-eclampsia 
Birth trauma
Induction of labour
C-section

Question 26

What are the foetal risks from pre-existing diabetes?

Answer 26

Miscarriage
Congenital malformation
Stillbirth 
Prematurity
Macrosomia 
Neonatal hypoglycaemia 
Neonatal death 
Obesity and/or diabetes in later life

Question 27

What treatment is given intrapartum for pre-existing diabetes

Answer 27

Variable rate IV insulin infusion - VRIII (sliding scale) <7mmol/L

Question 28

Describe the post natal care for women with pre-existing diabetes

Answer 28

T2DM resume taking metformin and glibenclamide while breast feeding
Look out for neonatal hypoglycaemia
Contraception