Pregnancy: Diabetes Mellitus/ Gestational Diabetes

Question 1

1 in how many pregnancies will be complicated by T2DM?

(Either pre-existing or developing during pregnancy)

Answer 1

1 in 40 pregnancies

Question 2

What are the risk factors for developing Gestational Diabetes?

Answer 2

• BMI of > 30 kg/m²
• Previous macrosomic baby weighing 4.5 kg or above
• Previous gestational diabetes
• First-degree relative with diabetes
• Family origin with a high prevalence of diabetes (South Asian, black Caribbean and Middle Eastern)

Question 3

WHO should you screen for gestational diabetes and HOW?

Answer 3

• Women who’ve previously had gestational diabetes:
  
  • OGTT at booking and, if the booking test is normal, at 24-28 weeks.
  • Regular self monitoring is an acceptable alternative.
• Women with any of the other risk factors should be offered an OGTT at 24-28 weeks

Question 4

What are the diagnostic thresholds for gestational diabetes?

Answer 4

• Fasting glucose is >= 5.6 mmol/l
• 2-hour glucose is >= 7.8 mmol/l

(Similar to the ADA criteria)

Question 5

How is gestational diabetes managed?

Answer 5

• Newly diagnosed women should be seen in a joint diabetes and antenatal clinic within a week
• Women should be taught about self monitoring of blood glucose
• Advice about diet (including eating foods with a low glycaemic index) and exercise should be given
• Pharmacoloical Treatment
  
  • If the fasting plasma glucose level is < 7 mmol//l a trial of diet and exercise should be offered
  • If glucose targets are not met within 1-2 weeks of altering diet/exercise metformin should be started
  • If glucose targets are still not met insulin should be added to diet/exercise/metformin (CONTINUE METFORMIN)
  • If at the time of diagnosis the fasting glucose level is >= 7 mmol/l insulin should be started
• If the plasma glucose level is between 6-6.9 mmol/l, and there is evidence of complications such as macrosomia or hydramnios, insulin should be offered
• Glibenclamide should only be offered for women who cannot tolerate metformin or those who fail to meet the glucose targets with metformin but decline insulin treatment

Question 6

How is pre-existing diabetes managed in pregnancy?

Answer 6

• Weight loss for women with BMI of > 27 kg/m^2
• Stop oral hypoglycaemic agents, apart from metformin, and commence insulin
• Folic acid 5 mg/day from pre-conception to 12 weeks gestation
• Detailed anomaly scan at 20 weeks including four-chamber view of the heart and outflow tracts
• Tight glycaemic control reduces complication rates
• Treat retinopathy as can worsen during pregnancy

Question 7

What are the targets for self monitoring of pregnant women? (pre-existing and gestational diabetes)

Answer 7

• Fasting - 5.3 mmol/l
• 1 hour after meals - 7.8 mmol/l
• 2 hour after meals - 6.4 mmol/l

Question 8

IF someone has gestational diabetes, what should they have for the rest of their lives?

Answer 8

Annual fasting plasma glucose

Question 9

What sort of post partum follow up is required for someone with gestational diabetes?

Answer 9

Fasting plasma glucose test at 6-13 weeks.