NICE (NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE)
https://www.nice.org.uk/guidance/cg192/chapter/1-Recommendations#recognising-mental-health-problems-in-pregnancy-and-the-postnatal-period-and-referral-2 (Last updated: 11 February 2020 )

Recognising mental health problems in pregnancy and the postnatal period and referral
1.5.1 Recognise that women who have a mental health problem (or are worried that they might have) may be:

• unwilling to disclose or discuss their problem because of fear of stigma, negative perceptions of them as a mother or fear that their baby might be taken into care
• reluctant to engage, or have difficulty in engaging, in treatment because of avoidance associated with their mental health problem or dependence on alcohol or drugs. [new 2014]
• 1.5.2 All healthcare professionals referring a woman to a maternity service should ensure that communications with that service (including those relating to initial referral) share information on any past and present mental health problem. [2014]

Depression and anxiety disorders
1.5. Recognise that the range and prevalence of anxiety disorders (including generalised anxiety disorder, obsessive‑compulsive disorder, panic disorder, phobias, post‑traumatic stress disorder and social anxiety disorder) and depression are under‑recognised throughout pregnancy and the postnatal period. [new 2014]