GDM

Question 1

What percentage of total pregnancies develop diabetes?

Answer 1

2.9%

Question 2

What percentage of diabetic obstetric patients have gestational diabetes?

Answer 2

90%

Question 3

What is the main risk for women who have pre-gestational diabetes?

Answer 3

High levels of glucose during organogenesis can cause miscarriage or foetal abnormalities

Question 4

What can happen to the foetus when women have GDM?

Answer 4

The increased maternal glucose leads to increased foetal glucose. This increase in glucose means that foetal insulin is also raised and this can increase fat storage and act as a growth hormone. This can result in a macrosomic baby.

Question 5

What is macrosomia?

Answer 5

Foetal birth weight of 4kg< (8lb13oz

Question 6

Which pregnancy hormones are responsible for GDM?

Answer 6

• Human Placental Lactogen (HPL)
• Cortisol
• Growth Hormone (GH)
• Progesterone

Question 7

What occurs with hormones in pregnancy to induce GDM?

Answer 7

HPL, cortisol, GH and progesterone all increase maternal glucose levels and increased insulin cellular resistance - this mechanism is to reduced maternal glucose utilisation to enhance the glucose availability to the foetus.

Question 8

When do we routinely screen for GDM?

Answer 8

26-28/40

Question 9

Which women do we screen for GDM?

Answer 9

1. BMI 30<
2. Previous macrosomic baby
3. Previous GDM
4. FHx of a first degree relative with diabetes
5. Ethnic origin (South Asian, Black Carribbean, Middle Eastern)

Question 10

What advice should be offered to patients with existing T1 or T2DM?

Answer 10

1. Weight loss (if appropriate)
2. Folic acid supplements (5mg OD)
3. Vitamin D supplementation (10mg OD)
4. End-organ dysfunction screening
5. Contraception until the pregnancy is wanted
6. Medication counselling - disease control is very important!

Question 11

What is the fasting and 1-hour post meal glucose targets in patients with GDM?

Answer 11

Fasting: <5.6mmol/l
Post-meal: <7.8mmol/l

THINK 5,6,7,8

Question 12

What 3 features may be suggestive that a woman has GDM?

Answer 12

1. Large for date foetus
2. Polyhydramnios
3. Glucose on urine dipstick

Question 13

Which medications can be used to treat GDM?

Answer 13

• Metformin

- Insulin

Question 14

How would you manage a patient who has a fasting glucose; Below 7mmol/l?

Answer 14

Trial diet and exercise

Move to metformin and insulin

Question 15

How would you manage a patient who has a fasting glucose; >7mmol/l?

Answer 15

Start insulin +/- metformin

Question 16

How would you manage a patient who has a fasting glucose; <6mmol/l + complications (e.g. macrosomia)?

Answer 16

Start insulin+/- metformin