Diabetes in pregnancy

Question 1

What are physiological changes in pregnancy which cause diabetes?

Answer 1

Placental hormones cause increased insulin resistance

This sometimes exceeds insulin reserves and develop raised glucose or GDM (gestational diabetes)

Treatment required later in pregnancy

Question 2

What is the effect of increased glucose levels in early pregnancy?

Answer 2

Increased risk of neural tube and cardiac abnormalities - teratogenic effect

Excessive fetal growth

Fetal hyper insulinamemia (maintains normal fetal glucose)

Question 3

What are neonatal problems relating to excess growth and glucose control?

Answer 3

Hypoglycaemia
Hyperbilirubinaemia
Poor adaptation to birth
Metabolic changes

Question 4

What is the pathophysiology of gestational diabetes?

Answer 4

Insulin resistance

Some endogenous insulin

Question 4

What does higher maternal glucose lead to?

Answer 4

Excess glucose across the placents

Question 5

How is gestational diabetes/T2 diabetes managed in pregnancy?

Answer 5

Diet and exercise
Metformin, sometimes insulin

Good control = better growth, easier birth

Birth 38-40 weeks (GDM)
Birth 37-40 weeks (T2)

Question 6

What is the pathophysiology of T1 diabetes in pregnancy?

Answer 6

Autoimmune beta islet cell destruction

No endogenous insulin

Insulin resistance later in pregnancy

Diagnosis usually before pregnancy (some DKA risk)

Question 7

How is T1 diabetes managed in pregnancy?

Answer 7

Always use insulin

Good control = less congenital defects

Birth 37-40 weeks

Question 8

What is the difference between onset in pregnancy of T2 diabetes and gestational diabetes?

Answer 8

T2 diabetes - raised glucose before pregnancy

GDM - raised glucose later in pregnancy

Question 9

What are maternal effects of diabetes?

Answer 9

Increase in:
- Miscarriage
- Pre-eclampsia
- Infection
- PTB - early induction of labour
- Caesarean section
- Induction labour
- Macrosomia
- Poor progress in labour

Question 10

What are fetal and neonatal effects of diabetes?

Answer 10

Increase in:
- Congenital malformation e.g. neural tube
- Macrosomia
- Birth risks e.g. shoulder dystocia
- Risk of stillbirth/neonatal death
- Polycythaemia
- Jaundice
- Fetal hypoglycaemia

Question 11

What are challenges to glycaemic control in pregnancy?

Answer 11

Hyperemesis
Early pregnancy insulin sensitivity
Later pregnancy insulin sensitivity

Question 12

What are the effects of diabetes on the kidneys in pregnancy?

Answer 12

Deterioration in diabetic nephropathy re increased GFR

Question 13

What are the effects of diabetes on the eyes in pregnancy?

Answer 13

Progression of diabetic retinopathy

Question 14

What are the effects of diabetes on birth in pregnancy?

Answer 14

Glucose control during birth complicated - may need variable rate insulin infusion which requires intense monitoring

Question 15

What is pre-pregnancy management of diabetes?

Answer 15

Optimise glycaemic control - aim HbA1c < 48mmol/mol if safe (hypoglycaemic risk

Advise against pregnancy if HbA1c >86mmol/mol

Pre-conception folic acid 5mg OD

Medications - Review (avoid ACE inhibitors, statins)

Eyes - Retinal screen (pre and during pregnancy)

Kidneys - Renal screen (BP, proteinuria, creatinine)

Question 16

What is antenatal management of diabetes?

Answer 16

Tight glycaemic control (fasting <5.3, 1hour <7.8)

Aspirin 150mgs from 12 weeks

Dating scan and anomaly scan (NTD and cardiac)

Growth scans (28,32,36 weeks)

Question 17

What is T2DM antenatal management?

Answer 17

continue metformin, STOP other DM treatments

often need insulin

Question 18

What is diabetic management during birth?

Answer 18

Timely birth - 37-40 weeks

Good glycaemic control before and during birth

Intrapartum glucose control - variable rate insulin

Antepartum corticosteroids PRN if birth before 36 weeks - risk of hyperglycaemia
(may need VRIII or insulin increase)

Question 19

What is post partum management of diabetes in the mother?

Answer 19

Insulin requirements reduce rapidly (placenta delivered)

Reduce treatment to pre-pregnancy levels

Further reduction especially if breast feeding

Question 20

What is post partum management of diabetes in neonates?

Answer 20

Test for hypoglycaemia

Early regular feeding -breastfeeding recommended

Breast feeding safe with insulin / metformin

Question 21

What are the GDM risk factors which are assessed?

Answer 21

• BMI >30kg/m2
• Previous macrosomic baby (>4.5kg)
• Previous GDM
• Family history diabetes in 1st degree
• Ethnic origin (asian, middle eastern, south european, afro-caribbean)
• PCOS
• Medications e.g. steroids, antiretrovirals, antipsychotics
• Glycosuria ++

Question 22

What is the diagnostic test for GDM?

Answer 22

Glucose tolerance test: 2 hour 75g oral glucose test

GDM if fasting ≥ 5.6 mmol/l or 2-hour ≥ 7.8 mmol/l

Question 23

What is antenatal GDM management?

Answer 23

Teach self monitoring of blood glucose: fasting and 1 hour post-prandial +/- bedtime

Diet and exercise

Metformin and/or insulin if CBGs not controlled

Glucose targets as per pre-existing diabetes

Assess fetal growth (growth scans from 28 weeks)

Delivery by 40+6 weeks

Question 24

What is GDM management at birth?

Answer 24

Good glucose control (insulin infusion)

Question 25

What is postpartum GDM managment?

Answer 25

STOP DM treatments - diabetes goes away as placenta is removed

Future tests for glycaemia

Diet and exercise

Annual fasting blood glucose or HbA1c

Question 26

What is the management of the baby after birth?

Answer 26

Early feeding and hypoglycaemia monitoring

Question 27

When does hyperglycaemia as a result of GDM resolve?

Answer 27

After delivery of the placenta

Question 28

What are risks of GDM to the mother?

Answer 28

PET, trauma due to larger baby

Question 29

What are risks of GDM to the fetus?

Answer 29

Macrosomia
Birth trauma
Shoulder dystocia
LSCS
Prematurity

Question 30

What are risks of GDM to the neonate?

Answer 30

Hypoglycaemia
Polycythaemia
Increased perinatal mortality rate