https://www.nice.org.uk/guidance/cg192

Antenatal and postnatal mental health: clinical management and service guidance.
2.1 “Preventing postpartum psychosis: What methods can improve the identification of women at high risk of postpartum psychosis and reduce this risk? Why this is important
Postpartum psychosis is a severe mental illness with a rapid onset and a major impact on the woman and her ability to care for her baby. It is associated with an increased risk of mortality in both the woman and her baby. Prophylactic treatment can be effective for women who are known to be at high risk, but for some women postpartum psychosis may be their first episode of severe mental illness. Better identification of women at high risk and a greater understanding of prophylactic and acute treatment would have a significant impact on maternal and child welfare, and on service costs.”