The management of pre-existing (type 1 and type 2) diabetes mellitus in pregnancy

Diabetes mellitus is common and complicates 2–5% of pregnancies in the UK, with an increasing prevalence of pre-existing diabetes mellitus in pregnancy. Hyperglycaemia directly correlates with adverse maternal and fetal outcomes, including congenital anomaly, miscarriage, pre-eclampsia, pre-term delivery, macrosomia, stillbirth and neonatal hypoglycaemia. Optimal glycaemic control before conception and during the antenatal period is paramount to reduce these risks. Pre-pregnancy preparation should focus on glycaemic control, medication review and end-organ disease assessment.