Improving outcomes in diabetes in pregnancy

One in 250 pregnancies in the UK involves diabetes. The majority of cases (87.5%) are gestational diabetes, 7.5% are type 1 and 5% are type 2 diabetes. Diabetes in pregnancy is associated with a five fold increase in risk of stillbirth and a two-fold increased risk of congenital defects compared with the general maternity population. Fasting blood glucose levels above 5.3 mmol/L can directly affect organogenesis, particularly of the fetal heart and spine. Hyperglycaemia can cause placental failure and stillbirth and for this reason early delivery is recommended. For women with pre-existing diabetes good blood glucose control prior to conception can minimise pregnancy risks towards levels approaching that of women without diabetes. The recommended glycated haemoglobin (HbA(1c)) target in preparation for pregnancy is 48 mmol/mol (6.5%) if this can be safely achieved. Women with an HbA(1c) 86 mmol/mol should be strongly advised against pregnancy. In normal pregnancy, the increased insulin resistance mediated by placental hormone secretion is compensated by increased maternal insulin secretion to maintain euglycaemia. Gestational diabetes arises from an inability to meet these increased insulin requirements adequately. Lifestyle modification with input from a specialist diabetes dietician is key to the management of gestational diabetes. Women with gestational diabetes have a significant lifetime risk of developing type 2 diabetes, hence diabetes screening must be undertaken on an annual basis in primary care.