Background: Women with perinatal substance problems experience a multitude of barriers to care. They have specific early intervention needs, they endure societal stigma, and both substances and mental health issues influence the way they navigate within support and treatment systems. Early interventions for women with perinatal substance problems are underresearched contexts. The aim of the study is to describe building relationships and engagement within an outreach and low threshold service encounter tailored for pregnant women with SUD (substance use disorder). Methods: The data consist of online written narratives from 11 workers involved in the program and feedback from 504 families in the recovery process comprising 228 open-ended answers. The data were analyzed with a thematic analysis. Results: The programs are characterized by flexibility and the implementation of inclusive ways to approach families. The themes for enhancing relationships and engagement within outreach and low threshold programs are Acceptance and attitude: a sensitive approach of approval; flexibility within strictness to allow for diversity and individuality; availability and space to ensure a trustful atmosphere; negotiating via doing to build connections; and everyday life changes: imagining recovery. The themes represent the need of being available, focusing on the worker’s attitudes and building connections by doing together, and visioning recovery together. Conclusions: The study results can add to the understanding of SUD outreach and low threshold work during pregnancy. The elements described in this study need further theoretical development, research and critical assessment. Building relationships during pregnancy were characterized by connecting within everyday life situations and supporting the development of an attachment relationship between the baby and the parents. To promote recovery, a comprehensive approach in which substance-related issues and mental health conditions are interconnected can be favored. Engaging early on during pregnancy might enhance success during future rehabilitation.