Gestational diabetes

Question 1

What does gestational diabetes refer to?

Answer 1

-refers to diabetes triggered by pregnancy. It is caused by reduced insulin sensitivity during pregnancy, and resolves after birth

Question 2

What are the complications for gestational diabetes?

Answer 2

• most significant immediate complication of gestational diabetes is a large for dates fetus and macrosomia
• This has implications for birth, mainly posing a risk of shoulder dystocia
• Longer-term, women are at higher risk of developing type 2 diabetes after pregnancy

Question 3

What are the risk factors for gestational diabetes?

Answer 3

• Previous gestational diabetes
• Previous macrosomic baby (≥ 4.5kg)
• BMI > 30
• Ethnic origin (black Caribbean, Middle Eastern and South Asian)
• Family history of diabetes (first-degree relative)

Question 4

What should be done for pts that have risk factors for gestational diabetes?

Answer 4

• should be screened with an oral glucose tolerance test at 24 – 28 weeks gestation
• Women with previous gestational diabetes also have an OGTT soon after the booking clinic

Question 5

What other features woyld suggest gestational diabetes and so would warrant an OGTT?

Answer 5

• Large for dates fetus
• Polyhydramnios (increased amniotic fluid)
• Glucose on urine dipstick

Question 6

Describe how an OGTT should be done

Answer 6

• An OGTT should be performed in the morning after a fast (they can drink plain water
• patient drinks a 75g glucose drink at the start of the test
• blood sugar level is measured before the sugar drink (fasting) and then at 2 hours

Question 7

What are normal OGTT results?

Answer 7

Normal results are:

• Fasting: < 5.6 mmol/l
• At 2 hours: < 7.8 mmol/l

Results higher than these values are used to diagnose gestational diabetes

Question 8

How are patients with gestational diabetes managed?

Answer 8

• managed in joint diabetes and antenatal clinics, with input from a dietician
• Women need careful explanation about the condition, and to learn how to monitor and track their blood sugar levels
• need four weekly ultrasound scans to monitor the fetal growth and amniotic fluid volume from 28 to 36 weeks gestation

Question 9

What is the initial management of gestational diabtetes?

Answer 9

• Fasting glucose <7 mmol/l–> trial of diet and exercise for 1-2 weeks, followed by metformin, then insulin
• Fasting glucose>7 mmol/l–>start insulin ± metformin
• Fasting glucose > 6 mmol/l plus macrosomia (or other complications)–>start insulin ± metformin

-Glibenclamide (a sulfonylurea) is suggested as an option for women who decline insulin or cannot tolerate metformin

Question 10

What are the target blood sugar levels for women with gestational diabetes?

Answer 10

• Fasting: 5.3 mmol/l
• 1 hour post-meal: 7.8 mmol/l
• 2 hours post-meal: 6.4 mmol/l
• Avoiding levels of 4 mmol/l or below