Table 1. PICAR statement.

PICAR framework	Eligibility criteria
Population, clinical indication(s), and condition(s)	Study population    •  Women/couples experiencing recurrent miscarriage (RM)    •  Humans only Clinical indication    •  Investigation, management and/or follow-up of women/couples with RM – specifically first trimester RM Clinical condition    •  RM; defined by the review team as the loss of two or more consecutive pregnancies 1, with a specific focus on first trimester RM. For the purposes of this review, all CPGs that focus on RM – regardless of the definition used – will be included. The definition applied by each included CPG will be extracted and considered when synthesising and interpreting the review findings
Interventions	•  Any intervention focusing on the investigation, management and/or follow-up of RM
Comparator(s), Comparison(s), and (key) Content	•  Any comparator or comparison    •  No ‘key’ CPG content is of interest – unless CPGs are broader in scope; in such instances, content specific to RM is only of interest
Attributes of eligible CPGs	Language    •  Available in English    •  CPGs where summaries are available in English, but full text is not, will be excluded Year of publication    •  2000 onwards    •  In Ireland, the National Clinical Effectiveness Committee (NCEC), requires a full guideline update within three years 24; while The Scottish Intercollegiate Guidelines Network (SIGN) also specifies three years, it also includes those over three years old and revalidated 26. The World Health Organisation does not have a defined period for guideline updates 27. To be comprehensive, CPGs published within the last twenty years (January 2000 to date) will be eligible for inclusion given that international CPGs concerning RM can fall well outside the three-year period 17, 28. A good quality older guideline could be a good base on which to develop a new guideline 29 Developing/publishing organisation    •  Only CPGs issued or endorsed by national or international scientific societies, professional colleges, charitable organisations, and government organisations will be included Country of publication    •  High-income countries, as defined by the World Bank 30; given the large discrepancies in pregnancy outcomes and care structures between high, and low and middle-income countries 31, 32 Version    •  Latest version only Development process    •  Evidence and/or consensus-based System of rating evidence    •  Use of a system to rate the level of evidence within CPGs is not an eligibility criterion; however, such data will be extracted to inform synthesis and interpretation of findings Quality of evidence    •  The eligibility of CPGs will not be based on a specific minimum quality cut-off score based on the AGREE II criteria.    •  We are interested in all guidance generated regardless of quality (e.g. because CPGs determined to be of ‘‘high quality’’ may not necessarily report recommendations that are highly valid and implementable 23); this will however be taken into consideration when synthesising and interpreting the review findings Scope    •  Must have a primary/secondary focus on the investigation and treatment of RM    •  Must be national/international in scope    •  Covers any aspect of RM care and its organisation; including the provision of dedicated pregnancy loss clinics, treatment and management of RM, investigations performed following RM in order to inform prognosis of future pregnancy outcomes, and counselling of parents following RM    •  Must be clearly identified as a CPG    •  Must be published. Unpublished CPGs, conference papers, discussion papers, drafts and opinions will be excluded Recommendations    •  Must have ‘recommendations’ concerning the identification, management and/or follow-up RM (either explicitly highlighted as such within the document, or noted within the body of the document, but not explicitly identified as a recommendation)    •  To be eligible, recommendations need not be accompanied by an explicit level of confidence (and quality assessment criteria system used specified); however, this data will be extracted (where available) and considered during the synthesis and interpretation of findings