This paper describes the development of systemic therapies in a Specialist Perinatal Mental Health Service (SPMHS) that developed Attachment Narrative Therapy (ANT) specifically for families in the perinatal stage of the family life cycle. ANT offers a good fit in the perinatal period, integrating systemic family therapy, narrative therapy, and attachment theory. From pregnancy to the child being two is a family life cycle stage of great change and reorganisation. This involves opportunities and challenges for attachments and relationships between parents, the baby and wider family/carers. Attending to cross-generational narratives and attachments are important in ensuring the perinatal stage is navigated successfully. Peri-ANT, a semi-structured version of ANT, was developed as a manualised approach. It can be flexibly adapted to the unique circumstances of each family. The paper describes the perinatal context, service needs and priorities, and the development of Peri-ANT including construction of the manual and how it was delivered.