Diabetes in pregnancy

Question 1

Risk factors for GDM

Answer 1

Obesity
Past Hx GDM
FHx diabetes
PCOS
Ethnicity (Asian, Indian, ATSI)

Question 2

When is screening done for GDM?

Answer 2

If risk factors present –> early OGTT in 1st trimester (or HbA1c)

If risk factors absent –> OGTT at 24-28wks

NB: during covid they are now doing a fasting BSL instead of OGTT to prevent pregnant women from sitting in a pathology clinic for hours (exposure risk)

Question 3

Diagnostic values for GDM

Answer 3

Any of the values below is diagnostic:

FBG > 5.1
1hr post-prandial >10
2hr post-prandial >8.5

Question 4

Maternal risks of GDM

Answer 4

Short term:

• Induced birth
• Operative birth
• PET
• PPH
• Polyhydramnios
• Infection

Long term:

• Recurrent GDM
• T2DM
• CVD

Question 5

Foetal/newborn risks of GDM

Answer 5

Short term:
Big baby
- Macrosomia
- Shoulder dystocia
- Nerve palsy
- LSCS
- Prematurity
Other
- hypoglycemia
- ARDS
- jaundice
- hypercalcaemia
- polycythemia
- HIE
- death

Long term:

• T2DM
• obesity

Question 6

Antenatal surveillance in GDM patients

Answer 6

Growth scans 2-4 weekly
Urine - ketones, proteinuria, glucose
Monitor weight - no more than 7-9kg weight gain throughout pregnancy.
BSL 4x daily (fasting, 2hrs post-prandials)
Routine bloods - FBC, UEC, LFTs, HbA1c, BSL

Question 7

BSL targets in GDM patients

Answer 7

Fasting <5
1 hr post-prandial <7.4
2hr post-prandial <6.7

Question 8

Management of a GDM pregnancy

Answer 8

1. Nutrition
   Low GI
   Involve dietician
2. Physical activity
   30 mins a day
3. Pharmacology:
   1st line - metformin
   2nd line - insulin with metformin (required in 50% of patients)

Question 9

Main side effects of insulin and metformin

Answer 9

Metformin: N+V, diarrhoea
Insulin: hypoglycaemia, injection site pain

Question 10

Timing of birth in GDM women

Answer 10

If GDM is managed with diet and there is no macrosomia –> await spontaneous labour.

If suspected macrosomia –> IOL at 38wks
<4000g –> VB
>4500g –> CS recommend (at 38-39 wks)

Question 11

Intrapartum management of GDM

Answer 11

Monitor BSL
Check ketones in urine
Continuous CTG if on medication, macrosomia or suboptimal CTGs.

Question 12

Neonatal management of a baby born to a GDM mother

Answer 12

Inform paeds
Baby should be fed within 1 hour of birth
Check BSL 4 hourly
Monitor for jaundice

Question 13

Components of pre-conception counselling in a patient with pre-existing diabetes

Answer 13

Optimise HbA1c. Avoid pregnancy if >10%.
Weight optimisation. Target BMI <27
High dose folate (5mg/day)
Assess for HTN, IHD, retinopathy, nephropathy.

Question 14

Risks of T1DM and T2DM in pregnancy

Answer 14

Maternal:

• DKA
• hypoglycaemia
• infection
• deterioration of retinopathy, nephropathy, angiopathy.
• miscarriage
• polyhydramnios
• PET
• shoulder dystocia
• inc LSCS rate

Foetal:

• congenital abnormalities (neural tube defects, sacral agenesis, congenital heart disease)
• macrosomia
• stillbirth
• neonatal hypoglycaemia
• jaundice
• polycythemia

Question 15

Management of T1DM or T2DM in pregnancy

Answer 15

Diabetes educator
Podiatrist
Ophthalmologist
Endocrinologist
Diet - low GI, high fibre
Metformin +/- insulin

Question 16

Overview the antenatal care provided in each trimester for T1DM and T2DM patients

Answer 16

1st trimester:
FBC, UEC, LFTs, HbA1c, BSL
Urine dip for proteinuria
Dating USS
Aspirin for PET prevention

2nd trimester:
Morphology scan

3rd trimester:
US at 34 wks (HC to AC ratio)