Background: Recent research and policy recognize care alumni (i.e., adults formerly in out-ofhome care [OHC]) as a population with a high accumulation of disadvantages well into adulthood, often in combination with early parenthood compared to the general population. Objective: The aim of this systematic review is to provide an overview on the impact of parental OHC on outcomes for both parents (i.e. parental adjustment, parenting) and their children (i.e. prevalence rates of OHC or child welfare system (CWS) involvement, adjustment, development), as well as protective and risk factors associated with those outcomes. Methods: Relevant articles were searched in four electronic databases from conception to 16 February 2022 according to PRISMA guidelines for systematic reviews; supplemented with handsearched citations from relevant references. Evidence was synthesized via a qualitative summary. Results: A total of 38 studies were included (19 quantitative, 14 qualitative, and 5 mixed-methods studies). Studies confirm increased rates of early parenthood among care alumni and an elevated risk of OHC among their children. However, most children remain with their care alumni parents, and some parents were met with the needed support to cope with challenging circumstances. Qualitative studies point to a great need for specialized services, including parenting programs that address past trauma and attachment issues. They also highlight potential protective factors. Conclusions: Findings suggest that care alumni parents experience compounding disadvantage, which may increase their children's risk of OHC. More research is needed on child adjustment, and on protective factors that can be leveraged to design effective interventions that decrease transgenerational CWS involvement.