title: Reducing repeat pregnancies in adolescence: applying realist principles as part of a mixed-methods systematic review to explore what works, for whom, how and under what circumstances.
abstract: Previous research has demonstrated emotional, psychological and educational harm to young mothers following unintended conceptions. The UK has one of the highest rates of pregnancies in adolescence in Western Europe with a high proportion of these being repeat pregnancies, making it a topic of interest for public health policy makers, and health and social care practitioners. As part of a wider mixed-methods systematic review, realist principles were applied to synthesise evidence about interventions aiming to reduce repeat pregnancies in adolescence.
  
  
  
  A multi-streamed, mixed-methods systematic review was conducted searching 11 major electronic databases and 9 additional databases from 1995 onwards, using key terms such as pregnancy, teen or adolescent. The principles of realist synthesis were applied to all included literature to uncover theories about what works, for whom, how and in what context. Initial theory areas were developed through evidence scoping, group discussion by the authors and stakeholder engagement to uncover context + mechanism = outcome (CMO) configurations and related narratives.
  
  
  
  The searches identified 8,664 documents initially, and 403 in repeat searches, filtering to 81 included studies, including qualitative studies, randomised controlled trials, quantitative studies and grey literature. Three CMO configurations were developed. The individual experiences of young mothers' triggered self-efficacy, notions of perceived risks, susceptibility and benefits of pregnancy, resulting in the adolescent taking control of their fertility and sexual encounters. The choice between motherhood and other goals triggered notions of motivations, resulting in the adolescent managing their expectations of motherhood and controlling their fertility and sexual encounters. Barriers and facilitators to accessing services triggered notions of connectedness and self-determination; resulting in interventions that are tailored so they are relevant to young persons, and improve access to services and engagement with the issue of pregnancy in adolescence.
  
  
  
  Pregnancy in adolescence is a complex issue with many factors to consider. The conceptual platform described here could help guide policy makers and professionals towards a number of areas that need to be attended to in order to increase the likelihood of an intervention working to prevent rapid repeat pregnancy in adolescence.
  
  
  
  PROSPERO CRD42012003168.
authors.affiliation: Centre for Health Economics & Medicines Evaluation, Ardudwy, Normal Site, Bangor University, Bangor, Gwynedd, LL57 2PZ, UK. j.charles@bangor.ac.uk.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Charles
authors.affiliation: School of Healthcare Sciences, Fron Heulog, Bangor University, Bangor, Gwynedd, LL57 2EF, UK.
authors.forename: Jo
authors.initials: J
authors.lastname: Rycroft-Malone
authors.affiliation: Liverpool Review and Implementation Group, University of Liverpool, Whelan Building, Brownlow Hill, Liverpool, L69 3GB, UK.
authors.forename: Rabeea'h
authors.initials: R
authors.lastname: Aslam
authors.affiliation: North Wales Centre for Primary Care Research, Gwenfro Units 4-8, Wrexham Technology Park, Wrexham, UK.
authors.forename: Maggie
authors.initials: M
authors.lastname: Hendry
authors.affiliation: North Wales Centre for Primary Care Research, Gwenfro Units 4-8, Wrexham Technology Park, Wrexham, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Pasterfield
authors.affiliation: Whitaker Research Ltd. Cae Ffos, Treborth Road, Bangor, Gwynedd, LL57 2RJ, UK.
authors.forename: Rhiannon
authors.initials: R
authors.lastname: Whitaker
mesh_terms: D000293:Adolescent; D001721:Birth Intervals / Q000523:psychology*; D005260:Female; D006801:Humans; D009035:Mothers / Q000523:psychology*; D009042:Motivation; D011247:Pregnancy; D011253:Pregnancy in Adolescence / Q000517:prevention & control / Q000523:psychology*; D049168:Pregnancy, Unplanned / Q000523:psychology; D036301:Qualitative Research; D016032:Randomized Controlled Trials as Topic; D012725:Sexual Behavior / Q000523:psychology
keywords: Adolescent; Mixed-methods systematic review; Pregnancy; Realist synthesis; Teen