Risk of stillbirth and preterm birth among undocumented pregnant migrant women in Denmark: A retrospective case-control study.

Aims: To examine the associations between undocumented pregnant migrant women and the risk of experiencing stillbirth or preterm birth.

Methods: A retrospective case-control study based on nationwide registers from Statistics Denmark and hospital journals from the seven largest hospital wards in Denmark from 1 January 2011 to 31 December 2018. A total of 882 undocumented pregnant migrant women and 3528 matched controls (both documented migrant and non-migrant women) were included.