Table 1.

Inclusion and exclusion criteria for peer-reviewed and grey literature.

Inclusion criteria	Exclusion criteria
Population
Care provided by midwives or nurse-midwives	Care provided by other health workers such as nurses without formal midwifery training, doctors, associate/auxiliary midwives, community health workers and traditional birth attendants
Care provided in low- and middle-income countries as defined by the World Bank	Care provided in high-income countries as defined by the World Bank
Intervention/comparison
Care where a midwife was the lead professional (whether a single midwife working alone, in a small team of midwives, a caseload model, or within an interdisciplinary team)	Care provided by midwives under the direction of a doctor or other health professional, or by midwives who are the lead professional only by default, i.e. the midwife is the only available professional but there is no obvious commitment to the philosophy of midwife-led care
Care provided in a dedicated (midwife-led) space either within or outside of a health facility*	Care provided in another type of space within a health facility (e.g. a maternity ward or obstetric unit) or outside of a health facility (e.g. at the client's home)
Care includes (but is not necessarily limited to) childbirth	Care does not include childbirth
Outcome
Existence of one or more spaces where midwife-led birthing care is provided	All other outcomes or none
Study design
Item is a research study, report of activities, opinion piece, or conference abstract	Item is a review of the literature
Year of publication was 2012 or later	Year of publication was before 2012
Published in English, French or Spanish	Published in other languages

^⁎We did not exclude facilities if they did not fully meet the ICM working definition of an MLBC, because one of our aims was to identify and describe their characteristics, rather than to assume that the working definition applies in all contexts.