Gestational Diabetes
Gestational diabetes = T2DM which initially presents during pregnancy and is usually asymptomatic
Epidemiology
Occurs in 3.5% of pregnancies
50% will continue to have T2DM afer giving birth
AetiologyRFss:
OverweightRObese before pregnancy
Age >35
Non-Caucasian
Previous episode of GDM
FHx of T2DM
Smoking
Underlying disease: HIV, PCOS, Acanthosis nigracans
Pathophysiology
1) Placenta releases hormones with anti-insulin activity - GH, ACTH, Cortisol, Progesterone, and hPLRHuman
placental lactogen (somatomammotropin)
2) This leads to a “diabetogenic state” so that the foetus has a constant supply of glucose. However it leads
to
- Increased insulin resistance
- Reduced peripheral uptake of glucose
3) Glucose remains high in the blood, more than is required for the foetus, resulting in maternal
hyperglycaemia
Presentation
Usually asymptomatic (incidental fnding)
If symptomatic, similar to T2DM – polydipsia, polyuria, lethargy, blurred vision (worst in 3rd trimester)
Diagnosis
High-risk women should be screened at week 24-28 (or week 16 if they’ve had it in previous pregnancy).
Screen at week 24-28 is any of the following:
- BMI >30
- Previous macrosomic baby
- Previous gestational diabetes
- FHx of diabetes (frst degree relative)
- Ethnicity is South Asian, black Caribbean, Middle East
- Glucosuria (2+ on 1 occasion, or 1+ on 2 or more occasions)
Positive results are:
- sasting glucose >5.6 mmolRL (in non-gestatonal diabetes this is usually >7.0mmol/L)
- OGTT (at 2hrs) >7.8 mmolRL (in non-gestatonal diabetes this is usually >11.1mmol/L)
Management
Fefer them all to a dietician
Fegular exercise – to improve blood glucose control. This is usually enough.
- if target glucose levels are not met within 1-2weeks of diet/exercise, ofer metformin
- an alternative is Glibenclamide, for those who cannot tolerate metormin or if metormin is not
working but they decline insulin.
Insulin – ofer long-acting insulin if
- fasting glucose is >7.0mmol/ at diagnosis
- fasting glucose 7.0mmol/ AND there are complications e.g. macrosomia or hydramnios
- fasting glucose is 7.0mmol/ BUT diet, exercise and metormin have not helped.
Note: Stop immediately afee giiing bieth.
Teach them self-monitoring of blood glucose. Targets are:
- fasting: <5.3 mmolRL
- 1hr-post meal: <7.8 mmolRL
Gestational diabetes = T2DM which initially presents during pregnancy and is usually asymptomatic
Epidemiology
Occurs in 3.5% of pregnancies
50% will continue to have T2DM afer giving birth
AetiologyRFss:
OverweightRObese before pregnancy
Age >35
Non-Caucasian
Previous episode of GDM
FHx of T2DM
Smoking
Underlying disease: HIV, PCOS, Acanthosis nigracans
Pathophysiology
1) Placenta releases hormones with anti-insulin activity - GH, ACTH, Cortisol, Progesterone, and hPLRHuman
placental lactogen (somatomammotropin)
2) This leads to a “diabetogenic state” so that the foetus has a constant supply of glucose. However it leads
to
- Increased insulin resistance
- Reduced peripheral uptake of glucose
3) Glucose remains high in the blood, more than is required for the foetus, resulting in maternal
hyperglycaemia
Presentation
Usually asymptomatic (incidental fnding)
If symptomatic, similar to T2DM – polydipsia, polyuria, lethargy, blurred vision (worst in 3rd trimester)
Diagnosis
High-risk women should be screened at week 24-28 (or week 16 if they’ve had it in previous pregnancy).
Screen at week 24-28 is any of the following:
- BMI >30
- Previous macrosomic baby
- Previous gestational diabetes
- FHx of diabetes (frst degree relative)
- Ethnicity is South Asian, black Caribbean, Middle East
- Glucosuria (2+ on 1 occasion, or 1+ on 2 or more occasions)
Positive results are:
- sasting glucose >5.6 mmolRL (in non-gestatonal diabetes this is usually >7.0mmol/L)
- OGTT (at 2hrs) >7.8 mmolRL (in non-gestatonal diabetes this is usually >11.1mmol/L)
Management
Fefer them all to a dietician
Fegular exercise – to improve blood glucose control. This is usually enough.
- if target glucose levels are not met within 1-2weeks of diet/exercise, ofer metformin
- an alternative is Glibenclamide, for those who cannot tolerate metormin or if metormin is not
working but they decline insulin.
Insulin – ofer long-acting insulin if
- fasting glucose is >7.0mmol/ at diagnosis
- fasting glucose 7.0mmol/ AND there are complications e.g. macrosomia or hydramnios
- fasting glucose is 7.0mmol/ BUT diet, exercise and metormin have not helped.
Note: Stop immediately afee giiing bieth.
Teach them self-monitoring of blood glucose. Targets are:
- fasting: <5.3 mmolRL
- 1hr-post meal: <7.8 mmolRL
