L19 Pregnancy and diabetes

Question 1

Why does diagnosing maternal hyperglycemia matter

Answer 1

It affords an opportunity to prevent:

• Morbidity in the offspring ‘from the uterus to the grave’
• An exacerbation of the obesity and type 2 diabetes epidemic
• Future type 2 diabetes in the mother

Question 2

The two types of groups at ANC booking - hyperglycaemia of pregnancy

Answer 2

• Women with normal glucose tolerance

- Women with abnormal glucose tolerance (known diabetes or IGT, unknown diabetes or IGT)

Question 3

Hyperglycaemia during pregnancy - possible scenarios - Pre-gestational hyperglycaemia

Answer 3

• Type 1 diabetes
• Type 2 diabetes(known or unknown)
• Monogenic diabetes
• Impaired glucose tolerance(IGT)

Question 4

Hyperglycaemia during pregnancy - posisble scenarios - ‘gestational diabetes’

Answer 4

• Any newly found abnormal GTT after the 1st trimester of pregnancy(ie diabetes or IGT)

Question 5

What is ‘gestational diabetes’ (GDM)

Answer 5

• WHO criteria (and NICE)
• Diabetes or impaired glucose tolerance (fasting glucose =/> 5.6 mmol/l)
• 2 hour GTT glucose
• International association of diabetes and pregnancy study group(outcome based HAPO study)

Question 6

Hyperglycaemia of pregnancy - IADPSG criteria

Answer 6

75g glucose tolerance test:

Fasting - 5.1 mmol/l
1 hour 10.0 mmol/l
2 hours 8.5 mmol/l

• Diagnose if 1 or more abnormal

Question 7

Hyperglycaemia in pregnancy - the problem

Answer 7

• Any degree of maternal hyperglycaemia during pregnancy can cause serious problems for the fetus

Question 8

What happens in the 1st trimester

Answer 8

Organogenesis:

• Carefully design the essential components
• Avoid mistakes (teratogenesis)
• Construct and programme the placenta

Question 9

What happens in the 2nd trimester

Answer 9

• Further complex development and linkage

Question 10

What happens in the 3rd trimester

Answer 10

• Accelerated growth

Question 11

Maternal metabolism changes - early pregnancy

Answer 11

Early pregnancy - facilitated anabolism

• Increased insulin sensitivity
• Glucose concentration slightly lower
• Increased maternal energy stores

Question 12

Maternal metabolism changes - later pregnancy

Answer 12

Later pregnancy - facilitated catabolism

• Increased insulin resistance
• Increased transplacental passage of nutrients
• Rapid fetal growth

Question 13

Effects of maternal hyperglycaemia - 1st trimester

Answer 13

Increased fetal abnormalities
- Fuel mediated teratogenesis

Abnormal placental programming

• Increased risk of pre-eclampsia
• Excessive glucose transport

Question 14

Effects of maternal hyperglycaemia - 3rd trimester

Answer 14

• Excessive fat deposition

- Adverse fetal programming(epigenetics)

Question 15

What can maternal hyperglycaemia leads to

Answer 15

• Fetal malformation
• Hydrocephalus
• Meningomyelocoele
• Central cyanosis in congenital heart disease
• Single ventricle and sacral dysgenesis
• Renal agenesis