Epidemiological studies which attempt to quantitatively assess any association between pregnancy loss and COVID-19. (Study designs may include prospective and retrospective cohort studies, case–control studies and cross-sectional studies.)

Non-English language publications including those where the summary is in English but not the full text.

Narrative review articles, guidelines, editorials or comments.

Studies without a control or comparison group, for example, case reports.

Conference presentations.