The numbers of Children in Need particularly those who become Looked After in the Public Care system are increasing in the UK. Risk factors for childhood vulnerability are understood in a general sense but the magnitude of risk attributable to particular factors alongside their possible value as risk predictors is less well understood. Similarly whilst there is evidence (for example from evidence provided by local authority Children's Services that Looked After Children have adverse health and social outcomes evidence on the magnitude of increased risk of these from contemporary population based samples is limited. Also limited is evidence how this risk may be ameliorated by other factors, including health and social care interventions. This lack of evidence mainly reflects the difficulty of studying these questions in population based studies. ALSPAC represents an opportunity to overcome these difficulties. From a population based sample of nearly 14,000 children recruited before birth Children in Need up to age 6 were identified from study data and from linkage to Child Health Records. Children who subsequently became Looked After are identified in the National Pupil Database to which ALSPAC participants are linked. As well as including information on category of vulnerability (such as neglect, physical abuse, sexual abuse, emotional abuse) the NPD also contains information on different types of Public Care provision (such as Local Authority Foster Care, Special Guardianship Orders, Kinship Care, Private Foster Care). ALSPAC are also linked to primary and secondary medical care records, education records including results of national assessments at Key Stages 1-5 and Criminal Records held in the Police National Computer. ALSPAC thus represents a valuable resource to answer questions around why some children enter Public Care, what happens to them subsequently and what difference do alternative models of care, and other factors, make to these outcomes