Diabetes in pregnancy

Question 1

What causes gestational diabetes

Answer 1

Increased energy requirements → mobilisation of glucose
Placenta releases human placental lactogen (HPL) and cortisol → physiological resistant state with relative glucose intolerance
Usually there is a compensatory double in insulin production, GDM = poor beta cell response

Question 2

What are the risk factors of GDM

Answer 2

Obesity (BMI >30kg/m2)
Age
Prior GDM
Previous macrosomic baby (>4.5kg)
Ethnicity with high risk (Afro-Caribbean, South-Asian)
Family history of T2DM
PCOS

Question 3

What is the prevalence of gestational diabetes

Answer 3

5% have pre-existing diabetes or gestational diabetes in pregnancy (4-5 in 100)

Question 4

What are the symptoms and signs of gestational diabetes

Answer 4

Polyuria
Polydipsia
Fatigue
Nocturia
Weight gain/loss

Calculate BMI
SFH and assessment for foetal size

Question 5

What investigations should be done for gestational diabetes

Answer 5

Bedside: Urine dipstick (glucose +) - glycosuria of 2+ on one occasion or 1+ on two or more

Bloods:
- Random blood glucose >11.1 (If >7.8 → OGTT at 16w)
- OGTT: Fasting >5.6, 2-hour >7.8
- HbA1c: >48 (T2)
- Renal screen

Other: ± CTG, US to assess size

Question 6

Describe the screening programme for GDM

Answer 6

1 or more risk factors -> will need screening for GDM:
- BMI > 30
- Previous Macrosomic Baby (Baby weight >4.5kg)
- GDM in previous pregnancy
- 1 of your parents of siblings has diabetes
- South Asian, Black, African-Carribbean or Middle Eastern origin

OGTT at 28 weeks
Anyone with previous GDM → asap after booking OGTT, then repeat 24-28w

Question 7

Describe the OGTT

Answer 7

1. Fast overnight (8-10 hours)
2. Blood test in clinic following fasting
3. Glucose drink
4. After 2 hours, repeat the blood test
   Body’s response to glucose analysed

Question 8

What is the overall management for Gestational diabetes

Answer 8

Seen in a joint diabetes and antenatal clinic within a week
Consultant-led care
MDT approach: diabetic specialist midwives/nurses/dietician/obs/physician
Antepartum/intrapartum/postpartum management

Question 9

What is the management of gestational diabetes antenatally

Answer 9

Increase folic acid to 5mg (until 12w)
Aspirin 75mg/day from 12 weeks → delivery
Self-monitor blood glucose 7x a day
Diet and exercise advice (low glycaemic index, Mediterranean diet, moderate intensity exercise)
Detailed anomaly USS scan with foetal cardiac examination- 20 weeks
Serial USS EVERY 4 weeks from 28-36 weeks- monitor foetal growth and amniotic fluid volume

Fasting glucose <7 → trial of exercise + diet
Targets not met in 1-2 weeks → metformin
Fasting glucose >7/FG 6-7 + complications:
- Insulin (basal bolus)
- Glibenclamide if metformin not tolerated and insulin declined

Question 10

Explain how self monitoring of glucose levels should be carried out in those with GDM and what are the targets

Answer 10

Monitor capillary blood glucose (7x a day):
- Fasting
- Before meals
- 1 hour post-meals
- Before bed time

Fasting: 5.3
1h: 7.8
2h: 6.4

Question 11

Describe the intrapartum care for gestational diabetes

Answer 11

Advise women to give birth no later than 40+6, offer IOL or ELCS if they have not given birth by this time
Large baby or maternal/foetal complications → consider LSCS
Monitor CBG every hour during labour and birth (GA used: every 30 minutes)
Glucose not maintained 4-7mmol/L → IV dextrose and insulin infusion
Steroids given → give insulin concurrently

Question 12

Describe the postpartum care for gestational diabetes

Answer 12

Immediately cease medical treatment for diabetes
Feed baby as soon as possible (within 30 minutes), then at frequent intervals (every 2-3 hours)
Blood glucose testing routinely 2-4 hours after birth
Follow up at a diabetic clinic
Offer Fasting plasma glucose test at 6-13 weeks post-delivery

Question 13

What are the complications of gestational diabetes

Answer 13

Maternal:
- Pre-eclampsia if have microvascular complications
- Renal impairment
- polyhydramnios
- Increased risk of PPH
- Increased risk of development T2DM later in life (if not pre-existing) - 50% of women with GDM develop T2DM
- Retinopathy

Foetal
- neonatal hypoglycaemia (hyperinsulinaemia)
- macrosomia or FGR
- Foetal injury at delivery e.g. shoulder dystocia
- Stillbirth
- HypoCa, HypoMg
- Congenital abnormalities e.g. tetFal, TGA, VSD, neural tube defects

Question 14

What is the prognosis for gestational diabetes

Answer 14

Very likely to have GDM is future pregnancies, can reduce risk with health weight, balanced diet and exercise before pregnancy
Majority will develop T2DM - test every year
Tight glycaemic control reduces complication rates

Question 15

What is the antenatal management for pre-existing diabetes in pregnancy

Answer 15

Pre-conception: advice, good diabetic control

joint diabetes and antenatal clinic every 1-2 weeks
Intense capillary blood glucose (CBG) monitoring - 4x a day fasting (aim <5.4) + 1 hour post meals BM (aim <7.8)
Retinal (digital imaging) and renal (albumin, Cr, GFR) screen at booking and repeated 2nd trimester
Regular growth scans every 4 weeks from 28 weeks
Aspirin 75mg from 12w
Folic acid 5mg
Detailed 20 week anomaly scan + doppler
T1DM: rtCGM, blood ketone testing strips, glucagon, keep fast-acting glucose available
T2DM: increase metformin dose, add insulin, STOP all other hypoglycaemics

Question 16

What is the intrapartum management for pre-existing diabetes in pregnancy

Answer 16

IOLD at 37-38w (prevent macrosomia and stillbirth)
Large baby → Consider LSCS
Monitor CBG every hour during labour and birth (GA used: every 30 minutes) - maintain 4-7

Question 17

What is the postpartum management for pre-existing diabetes in pregnancy

Answer 17

Revert back to pre-pregnancy dose of medications, immediately
Feed baby as soon as possible (within 30 minutes), then at frequent intervals (every 2-3 hours)
Blood glucose testing routinely 2-4 hours after birth
Follow up at a diabetic clinic
Can continue metformin and insulin during breastfeeding