Gestational diabetes is defined by the WHO as 'carbohydrate intolerance resulting in hyperglycaemia of variable severity with onset or first recognition during pregnancy'.1
NICE guidelines state that high- risk women should be screened for gestational diabetes. This includes those with:
- BMI >30kg/m².
- Previous macrosomia - baby's birth weight ≥4.5kg.
- Previous gestational diabetes.
- First-degree relative with diabetes.
- Ethnic origin with high prevalence of diabetes (eg South Asian, black Caribbean or Middle Eastern).
The most cost-effective screening method is the two hour 75g oral glucose tolerance test.1,2
The WHO states that gestational diabetes occurs in two to nine per cent of all pregnancies globally, but varies in proportion with the prevalence of type 2 diabetes in a given population or ethnic group.1 In the UK, the prevalence of gestational diabetes is estimated to be two to 12 per cent.3 It usually presents after the 28th week of pregnancy and is rarely noted before 20 weeks; hyperglycaemia before this time usually indicates undiagnosed type 2 diabetes.