Eligibility criteria
Cohort, cross-sectional, and retrospective studies investigating the causes of stillbirths in singleton pregnancies in various ethnic groups in high income countries were eligible for inclusion. Studies that only reported risk factors associated with stillbirth in various ethnic groups but did not investigate the actual cause of foetal death were excluded. Reports were also excluded if they did not provide data on causes in an extractable format. Given the considerable heterogeneity in the definition of stillbirth between studies, we did not specify a pre-determined definition to use as an eligibility criterion.