Gestational diabetes

Question 1

What is gestational diabetes?

Answer 1

Insufficient insulin secretion to compensate for insulin resistance in pregnancy
Gestational diabetes is diabetes seen for the first time during pregnancy

Question 2

What are the risk factors for GDM?

Answer 2

Previous GDM
Previous macrosomic baby
BMI > 30
Ethnicity
Family history of diabetes
PCOS

Question 3

What are the physiological differences in insulin in pregnancy?

Answer 3

Increased insulin resistance (in the second and third trimester)

Question 4

What are the physiological differences in glucose in pregnancy?

Answer 4

Fasting and post meal levels of glucose are decreased

Question 5

What are the symptoms of gestational diabetes?

Answer 5

Most women are asymptomatic

Question 6

What is the main investigation for gestational diabetes?

Answer 6

Oral glucose tolerance test

Question 7

What OGTT results will be seen in a woman with gestational diabetes?

Answer 7

Fasting glucose > 5.6 mmol/L
At 2 hours > 7.8 mmol/L

Question 8

When should OGTT be performed to diagnose gestational diabetes?

Answer 8

Between 24-28 weeks

Question 9

Who is an OGTT performed on?

Answer 9

Any woman with risk factors for gestational diabetes, plus anyone with features that suggests gestational diabetes:
- Large for dates fetus
- Polyhydramnios
- Glucose on urine dipstick

Question 10

What are the fetal complications of gestational diabetes?

Answer 10

Macrosomia
Pre-term delivery
Neonatal hypoglycaemia
Increased risk of developing type 2 diabetes later in life
Congenital heart disease
Neonatal jaundice

Question 11

What are the maternal complications of gestational diabetes?

Answer 11

Increased risk of hypertension
Increased risk of pre-eclampsia
Increased risk of developing type 2 diabetes later in life
Increased risk of recurrent GDM with next pregnancy

Question 12

What is the first line management of gestational diabetes?

Answer 12

Fasting glucose < 7 mmol/L - trial of diet and exercise
Fasting glucose > 7 mmol/L - insulin + metformin
Fasting glucose 6-6.9 mmol/L with evidence of macrosomia - insulin + metformin

Question 13

What medication can be used as an alternative to metformin in gestational diabetes?

Answer 13

Glibenclamide (sulfonylurea)

Question 14

What are the target glucose levels for women with gestational diabetes?

Answer 14

Fasting - 5.3 mmol/L
1 hour post meal - 7.8 mmol/L
2 hours post meal - 6.4 mmol/L

Question 15

What type of screening should mothers with pre-existing diabetes be offered during pregnancy?

Answer 15

Retinopathy screening when the woman becomes pregnancy, and at 28 weeks

Question 16

When should women with pre-existing diabetes have given birth by?

Answer 16

Between 37 and 38+6 weeks

Question 17

How long should diet and exercise be trialled in women with gestational diabetes?

Answer 17

1-2 weeks - offer metformin if glucose levels have not improved
Offer insulin if glucose levels have still not improved

Question 18

What medication can be added to insulin in women with gestational diabetes?

Answer 18

Metformin

Question 19

When should pregnant people with previous gestational diabetes be screened during their next pregnancy?

Answer 19

At booking, and again at 24-28 weeks