Lucchini-Raies, CamilaMarquez-Doren, FranciscaBeca, PaulinaPérez Ewert, J. CarolaCampos, SolangeLopez-Dicastillo, Olga2021-08-042021-08-042020-07Journal of Advanced Nursing, 2020, vol.76:3641–3653https://doi.org/10.1111/jan.14534http://hdl.handle.net/11447/4223Aim: To report a pilot study protocol to assess the feasibility of a complex intervention, in the primary healthcare context, to support women and their families in breastfeeding. Design: A pilot/feasibility trial with control and intervention groups. Methods: The study will be conducted in two primary healthcare centres with 40 childbearing women (20 control group; 20 intervention group), with their partner/ meaningful person and their respective healthcare professionals. Intervention group participants will receive the intervention: (a) in a breastfeeding workshop during their third trimester of pregnancy; and (b) via virtual breastfeeding support for six months postpartum. Health professionals will be trained to deliver the intervention. The control group will receive standard care in the outpatient clinic. The pilot will help determine the intervention's feasibility. Data collected pre-intervention, 10-days postpartum and two-, four-, and six-months postpartum will provide estimates of the intervention's preliminary effects on self-efficacy and main outcomes. Research Ethics Committee approval was obtained in April 2019. Discussion: Breastfeeding support is a complex reality influenced by multiple factors. Therefore, approaches to breastfeeding are also, requiring interventions that address its multidimensional nature, including all actors involved. The proposed intervention will be applied by an interdisciplinary professional health team, allowing for its incorporation into standard practice and its perpetual maintenance. Impact: The study will produce an original, comprehensive, complex intervention addressing contextual, and organizational factors to promote breastfeeding support using an interdisciplinary and family-based approach; breastfeeding self-efficacy is the core concept. The program evaluation and feasibility study will permit exploration of the integration of the intervention's novel aspects into the daily work of professionals and reveal how to better use existing resources in a full-scale clinical trial. Trial registration: ClinicalTrials.gov ID: NCT03944642.enBreastfeeding self-efficacyBreastfeeding supportComplex interventionMidwivesNursingPilot studyPrimary health careArticle