Funding for this research was provided by:
Sundhed og Sygdom, Det Frie Forskningsråd (DFF-4183-00353)
Text and Data Mining valid from 2018-10-05
Received: 28 April 2018
Accepted: 28 August 2018
First Online: 5 October 2018
Ethics approval and consent to participate
: The study was entirely based on data from an existing cohort and Danish national health registers and was approved by the Danish Data Inspection Agency, which by Danish law serves as ethical approval of register-based research. No contact has been made with participating women, their relatives, or their practicing doctors, and no consent to participate was needed, according to Danish law. The study was approved in accordance with the Danish Data Protection Agency (ExternalRef removed/).
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.