Purpose: Up to 40% of parents of children with cancer experience relationship distress; a significantly higher proportion compared to the general population. Despite this elevated risk, there are few in-depth qualitative studies investigating relationship distress in the paediatric oncology context. Therefore, this study aimed to explore how parents of children with cancer experience relationship distress to thereby generate an in-depth understanding of the phenomenon.

Method: A sample of 25 parents (17 mothers, 8 fathers) who had experienced relationship distress related to their child's cancer participated in semi-structured interviews exploring relationship dynamics, communication, conflict management, and relational changes following the child's diagnosis. The interviews were audio-recorded, transcribed verbatim, and analysed using inductive content analysis.

Results: Three categories and nine subcategories were identified. In addition to these, one overarching theme emerged. The first category 'Pressure on the relationship', illustrated factors that placed strain on the couple relationship. The second category 'When unity fails' included parents' experiences of challenges in dealing with the situation together as a couple. The third category 'Fractured togetherness' highlighted relationship deterioration as a result of the cancer experience. The theme 'Fighting together, yet drifting apart' linked the categories by illustrating the process of experiencing joint hardships, of trying to manage these together, but ending up with a wounded relationship.

Conclusion: This study contributes with an in-depth understanding of relationship distress in parents of children with cancer. Thereby, it can contribute to the development of currently limited interventions to support parents' couple relationships in paediatric oncology care.