Diabetes in pregnancy

Question 1

Risk factors for gestational diabetes

Answer 1

BMI > 30

Previous macrosomic baby >4.5kg

Previous gestational diabetes

First-degree relative with diabetes

Family origin with high prevalence diabetes (South Asian, Black Caribbean, Middle Eastern)

Question 2

Screening for gestational diabetes

Answer 2

OGTT test of choice

Women who previously had GD: OGTT as soon as possible after booking and at 24-28 weeks if first test normal

Women with any other risk factors: OGTT 24-48 weeks

Question 3

Diagnostic threshold for gestational diabetes

Answer 3

Fasting glucose >5.6

2 hour glucose >7.8

Question 4

Management of GD

Answer 4

Advice about diet and exercise

If fasting glucose <7 trial diet and exercise
- if targets not met 1-2 weeks start metformin
- if targets still not met add insulin (short acting)

If at time of diagnosis glucose >7 insulin should be started

Question 5

When to offer glibenclamide

Answer 5

Women who cannot tolerate metformin or those who fail to meet glucose targets with metformin but decline insulin treatment

Question 6

Management of pre-existing diabetes

Answer 6

Weight loss for women with BMI >27

Stop oral hypoglycaemic agents, apart from metformin, and start insulin

Folic acid 5mg/day from pre-conception to 12 weeks gestation

Detailed anomaly scan at 20 weeks

Treat retinopathy as can worsen during pregnancy

Question 7

Targets for self-monitoring

Answer 7

Fasting- 5.3mmol/L

1 hour postprandial- 7.8mmol/L

2 hour postprandial- 6.4mmol/L