Women with obesity, particularly BMI ≥35. This is best addressed pre-pregnancy.

Women taking medication known to be harmful or not recommended in pregnancy; some such as valproate should be avoided, and others such as angiotensin-modulating drugs should be substituted for safer options.

Women intending to become pregnant who have chronic or complex disease or disability. These include poorly controlled epilepsy, hypertension, diabetes, thyroid disease (including subclinical hypothyroidism), renal or heart disease, or inflammatory conditions such as rheumatoid arthritis and inflammatory bowel disease.

Women with depression should have their need for medication reviewed; those with severe mental health diagnoses, including alcohol and drug addiction (cocaine can be particularly harmful), should be referred.

Women with a history of venous thromboembolism and haemoglobinopathies.

Women with three or more consecutive miscarriages.

Women with previous complications of pregnancy, for example, pre-eclampsia, gestational diabetes, or obstetric cholestasis.

Women with a personal or family history of an inherited disorder, for example, polycsytic kidney disease.

Women in social circumstances where an additional child or the pregnancy may be at risk.