Background <p>Maternal mental health difficulties, associated with perinatal loss, a traumatic birth or fear of childbirth, are common and yet often left untreated. Maternal Mental Health Services were set up as part of the National Health Service (NHS) Long Term Plan to address this gap and provide psychological treatment and specialist midwifery care to women and birthing people experiencing maternal mental health difficulties using trauma-informed frameworks. This study aimed to evaluate the establishment and initial treatment outcomes of the Maternity Trauma &amp; Loss Care Service (MTLC), a Maternal Mental Health Service, for women and birthing people affected by perinatal trauma, loss, and tokophobia.</p> Method <p>The sample includes all women and birthing people (<i>N</i> = 254) referred to the Maternity Trauma &amp; Loss Care Service over the 12-month period from 1st April 2022 to 31st March 2023. Data were analysed using a mixed‐methods cross‐sectional design.</p> Results <p>Of the 72 clients with completed outcome measures, a reduction in the proportion of clients reporting clinically significant levels of psychological distress between the start and end of treatment from 77 to 29% was observed. The proportion of clients reporting clinically relevant symptoms of post-traumatic stress was reduced from 80% pre-treatment to 15% post-treatment. The 17 clients who provided feedback, overall reported that, as a result of accessing the service, they felt supported, listened to and advocated for whilst they received maternity care.</p> Conclusion <p>This study provides useful insights about Maternal Mental Health Services, that they fill a clear gap for women and birthing people with mental health difficulties related to pregnancy, birth and perinatal loss. It highlights areas for future research and barriers for implementing these services.</p>