Gestational diabetes mellitus (GDM) is diabetes (high blood glucose) that develops during pregnancy. GDM is usually diagnosed from a blood test 24 to 28 weeks into pregnancy. Women with GDM don’t have diabetes before their pregnancy, and it usually goes
away after giving birth.
In the UK, roughly 16 out of every 100 women will develop GDM.
The most common problem associated with GDM is a large baby (macrosomia), which can make vaginal delivery more difficult and may mean caesarean section is required.