Funding for this research was provided by:
Vetenskapsrådet (project 2014-3561)
Stockholms Läns Landsting (ALF project grant 20150118)
Received: 2 November 2018
Accepted: 25 April 2019
First Online: 28 May 2019
Ethics approval and consent to participate
: The Regional Ethical Board in Stockholm approved the study. Permission was obtained to access clinical data from all pregnancies resulting in a birth of an infant at 22 gestational weeks or later in Stockholm and Gotland from 2008 to 2014, and to study pregnancy and delivery complications using this database.Reference numbers 2009/275–31, 2012/365–32 and 2014/962–32
: The authors declare that they have no competing interests.
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