BackgroundThis protocol is for a feasibility study of a mindfulness-based stress reduction (MBSR) program adapted for pregnant women with psychosocial vulnerabilities. The rationale for the study is the need for a wider array of evidence-based options to address prenatal mental health care needs in pregnant women. MBSR is a promising mental health intervention but has not yet been adapted for pregnant women with the aim of addressing prenatal mental health. The purpose is thus to evaluate the feasibility, acceptability, and clinical outcomes of an adapted MBSR program, prenatal MBSR, compared to usual care to inform a randomized controlled trial.Methods/designPregnant women (n = 60) referred to an outpatient clinic at Copenhagen University Hospital, Amager and Hvidovre, Denmark, will be recruited for the study. The design is a single-center feasibility trial, with prenatal MBSR, as an add-on to usual care. The primary outcome is to assess the feasibility of a full-scale randomized controlled trial. The secondary feasibility outcome includes possible effects of the adapted MBSR program estimated by self-report questionnaires measuring stress, anxiety, depression, well-being, decentering, reflective functioning, mindfulness, and compassion. Participants will be randomized in a 1:1 ratio to prenatal MBSR or usual care.DiscussionThe study is part of the Good Start to Family Life study anchored at Copenhagen University Hospital, Amager and Hvidovre, Denmark. Teaching the skills of mindfulness meditation to a psychosocially vulnerable group of pregnant women could prove a viable and non-pharmacological approach to reduce stress, improve mental health, and provide support in the transition to parenthood. The outcomes of the feasibility study will inform the design of a fully powered randomized controlled trial.Trial registrationClinicalTrials.gov, NCT04571190. Registered on September 30, 2020