Introduction

This guideline updates and replaces 'Diabetes in pregnancy' (NICE guideline CG63). The recommendations are labelled according to when they were originally published (see about this guideline for details).

Approximately 700,000 women give birth in England and Wales each year, and up to 5% of these women have either pre‑existing diabetes or gestational diabetes. Of women who have diabetes during pregnancy, it is estimated that approximately 87.5% have gestational diabetes (which may or may not resolve after pregnancy), 7.5% have type 1 diabetes and the remaining 5% have type 2 diabetes. The prevalence of type 1 diabetes, and especially type 2 diabetes, has increased in recent years. The incidence of gestational diabetes is also increasing as a result of higher rates of obesity in the general population and more pregnancies in older women.

Diabetes in pregnancy is associated with risks to the woman and to the developing fetus. Miscarriage, pre‑eclampsia and preterm labour are more common in women with pre‑existing diabetes. In addition, diabetic retinopathy can worsen rapidly during pregnancy. Stillbirth, congenital malformations, macrosomia, birth injury, perinatal mortality and postnatal adaptation problems (such as hypoglycaemia) are more common in babies born to women with pre‑existing diabetes.

This guideline contains recommendations for managing diabetes and its complications in women who are planning pregnancy and those who are already pregnant. The guideline focuses on areas where additional or different care should be offered to women with diabetes and their newborn babies. Where the evidence supports it, the guideline makes separate recommendations for women with pre‑existing diabetes and women with gestational diabetes. The term 'women' is used in the guideline to refer to all females of childbearing age, including young women who have not yet transferred from paediatric to adult services.

Reasons for this update

Several developments have occurred since publication of the original Diabetes in pregnancy guideline in 2008 that have prompted this update.

New studies on diagnosing and treating gestational diabetes have been published. The landmark HAPO (Hyperglycemia and Adverse Pregnancy Outcomes) study resulted in consensus guidance on the definition of gestational diabetes that has been adopted by the World Health Organization and which would result in many more women being diagnosed with gestational diabetes. This has been the subject of wide debate, and a cost–benefit analysis of the new guidance was a priority for this guideline update.

Other topics that have been reviewed include using newer technologies for monitoring blood glucose (for example, continuous glucose monitoring) and blood ketones, the role of HbA1c (glycated haemoglobin) levels in diagnosing diabetes in pregnant women and managing their diabetes, the role of specialist (multidisciplinary) teams, blood glucose targets before and during pregnancy, and the timing and best test for diagnosing continuing glucose intolerance in women after the birth.

Medicines

The guideline will assume that prescribers will use a medicine's summary of product characteristics to inform decisions made with individual patients.

This guideline recommends some medicines for indications for which they do not have a UK marketing authorisation at the date of publication, if there is good evidence to support that use. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. The patient (or those with authority to give consent on their behalf) should provide informed consent, which should be documented. See the General Medical Council's Good practice in prescribing and managing medicines and devices for further information. Where recommendations have been made for the use of medicines outside their licensed indications ('off‑label use'), these medicines are marked with a footnote in the recommendations.

  • National Institute for Health and Care Excellence (NICE)