The population of adults with single-ventricle congenital heart disease (CHD) is growing. This study explores their lived experiences through an adult developmental psychology framework.

Individuals aged 18 and older with single-ventricle CHD participated in Experience Group sessions and 1:1 interviews. Sessions were transcribed and analysed thematically. Themes were categorized by developmental domains and age group.

Of the 29 participants, 18 (62%) were female, 10 (35%) were emerging (18–29 years), 13 (45%) were established (30–45 years), and 6 (21%) were midlife adults (46–60 years). Emerging adults expressed reluctance to initiate romantic relationships and fear of burdening partners, while established adults reported strong relationships with partners deeply involved in caregiving. Emerging adults struggled with finding fulfilling work that meets their health needs, whereas established and midlife adults faced unemployment or early retirement due to health limits. Family dynamics shifted, with established and midlife adults educating their children to become caregivers. Physical limitations and low self-rated health were consistent across life stages, and midlife adults did not worry about traditional chronic conditions. Mental health concerns, including anxiety and depression, persisted across all life stages, but resiliency and positive affect were also evident.

Adults with single-ventricle CHD experience developmental milestones differently, indicating the need for early anticipatory guidance in these domains to achieve optimal outcomes in adulthood.