Up to one third of women perceive their delivery as traumatic, but between three to four per cent of women after childbirth in community samples and around 16–19 per cent of women in high-risk groups develop post-traumatic stress disorder (PTSD). Furthermore, a substantial number of women suffer from clinically significant PTSD symptoms, even though their symptoms remain below the diagnostic threshold level. Recent evidence on the intergenerational transmission of trauma underlines the relevance and far-reaching consequences not only for the mother but also for her offspring, as maternal PTSD is associated with mother-infant relationship problems, as well as negative developmental outcomes of the infant. PTSD following childbirth thus represents a major public health issue and early interventions to target this are called for. This chapter provides an overview of the current evidence and understanding of PTSD following childbirth by describing scientific evidence and theoretical models regarding protective and risk factors of PTSD after childbirth, its impact on maternal, child, and couple outcomes, its economic costs, as well as evidence-based preventative measures and interventions.