Table 1

List of databases and resources searched

Electronic databases searchedDate of search
1. Ovid multifile search (MEDLINE, EMBASE, PsycINFO)10 March 2017
2. POPline (via http://www.popline.org/), 1970–present10 March 2017
3. ProQuest multifile search10 April 2017
4. Applied Social Sciences Index Abstracts on ProQuest, 1987–current26 May 2017
5. Ovid MEDLINE 1948– and MEDLINE In-Process & Other Non-Indexed Citations to daily update26 July 2017 with monthly alert thereafter (cut-off date for included results 31 December 2017)
6. Ovid EMBASE, 1980–2017 week 113 August 2017 with monthly alert thereafter (cut-off date for included results 31 December 2017)
7. CINAHL Plus with Full Text/EBSCOhost to 201711 August 2017 with monthly alert thereafter (cut-off date for included results 31 December 2017)
8. Ovid PsycINFO, 1972–March 2017 week 314 August 2017 with monthly alert thereafter (cut-off date for included results 31 December 2017)
9. MIDIRS on Ovid, 1971–April 201718 August 2017
10. HMIC on Ovid, 1979 to date18 August 2017
11. Thomson Reuters Web of Science, 1900–201718 August 2017
Grey literature sources
 1. British Library Ethos (ethos.bl.uk)
 2. Networked Digital Library of Theses and Dissertations (www.ndltd.org)
 3. National Institute for Health and Care Excellence (https://www.nice.org.uk)
 4. Trove - National Library of Australia (trove.nla.gov.au)
 5. OpenGrey (http://www.opengrey.eu/)
 6. Google
 7. Google Scholar
 8. Experts in the field
  • HMIC, Health Management Information Consortium; MIDIRS, Midwives Information & Resource Service.