The contributions of fertility during adolescence to disability across the life-course: hypothesized causal pathways, research gaps, and future directions.

Context: Robust associations have been identified between fertility during adolescence and the disablement process, including pathologies, impairments, functional limitations and disability. Limited theoretical or empirical research considers how and why such relationships exist generally or with the individual associated components of disablement.

Objective: To consolidate and critically evaluate literature to describe testable, theory-based hypotheses to guide future research on the mechanisms by which fertility during adolescence contributes to disablement.

Methods: Targeted literature review of research from diverse global settings contextualised in two well-accepted theoretical frameworks in life-course epidemiology: the cumulative risk model and the critical period approach.

Results: Five hypothesised causal pathways linking adolescent fertility to disablement in later life are described: 1) Causal relationship initiated by fertility during adolescence; 2) Common cause(s) for both, such as adverse childhood experiences; 3) Contributing cause(s) to adolescent fertility; 4) Interaction between adolescent fertility and other risk factors; and 5) Critical period effects unique to adolescence. Most research on the topic is on pathologies versus functional limitations and disability.

Conclusion: We highlight promising research avenues to inform future research and interventions on adolescent fertility and the disablement process. This work provides theoretical clarity, identifies research gaps, and offers hypotheses-testing opportunities for future research.