GDM/ Obesity in pregnancy

Question 1

When do you screen for GDM?

Answer 1

At 28 weeks’ via OGTT, or earlier (16 weeks’) if high risk (ethnicity, FHx, high BMI, GDM in previous pregnancy, macrosomia, PCOS) but they must still repeat at 28 weeks’

Question 2

What are the dx values for GDM on OGTT?

Answer 2

Fasting >5.1 (7 or above = pre-existing DM)
1hr ≥ 10.0
2hr >8.5 (11 or above = pre-existing DM)

Question 3

What are the BMI classes?

Answer 3

<18.5 = underweight
18.5-24.9 = normal
25.0-30.0 = overweight
>30 = obese

Question 4

What is the normal amount of weight gain in pregnancy for women with a normal BMI?

Answer 4

Should put on 11.5-16kg if normal weight (but not before 20 weeks’)

Question 5

How do you calculate BMI?

Answer 5

Weight (kg)/ Height ^2 (m)

Question 6

What is the normal amount of weight gain in pregnancy for women with a high BMI (of all obese classes)?

Answer 6

5-9kg

Question 7

What are the target BSLs in pregnancy?

Answer 7

Fasting = <5.5 mmol/L
Postprandial = <6.5 mmol/L

Question 8

What diabetic medications should you avoid in pregnancy and which are safe?

Answer 8

Metformin and insulin are safe - women should ideally convert to insulin prior to conception
Other oral hypoglycaemic agents are contraindicated - avoid sulphonylureas and glitazones

Question 9

What other cardiometabolic medications should be avoided in pregnancy?

Answer 9

ACE/ ARBs and statins are contraindicated due to effects on the fetus

Question 10

What should you do for the neonate after birth if the mother has GDM?

Answer 10

Check BSLs straight after birth
If they are hypoglycaemic, encourage breastfeeding early
If this doesn’t work then formula feeding, then IV dextrose, then gel dextrose

Question 11

What are some complications of GDM?

Answer 11

Mother - increased risk of pregnancy induced HTN, preeclampsia, premature delivery, infection e.g. UTI, C/S
Fetal - macrosomia, stillbirth
Neonatal - hypoglycaemia, shoulder dystocia

Question 12

Who does a MDT involve for GDM?

Answer 12

Obstetrician
Diabetic educator
Dietitian
Neonatal paediatrician

Question 13

What is the follow up for a woman with GDM?

Answer 13

Need to be screened 6 weeks postpartum for diabetes as there is a 50% risk of developing T2DM in the next 20 years after having GDM

Question 14

What are some complications of obesity in pregnancy?

Answer 14

Mother - increased risk of GDM, preeclampsia, reduced lactation, prolonged labour and C/S, difficult epidural/ intubation
Fetal - macrosomia, congenital abnormalities, stillbirth
Neonatal - shoulder dystocia, obesity later in life