About the Authors

Rie Adser Virkus

Affiliation Department of Obstetrics & Gynecology, Hillerød Hospital, University of Copenhagen, Hillerød, Denmark

Ellen Løkkegaard

ELOE0002@regionh.dk

Affiliation Department of Obstetrics & Gynecology, Hillerød Hospital, University of Copenhagen, Hillerød, Denmark

Øjvind Lidegaard

Affiliation Gynecological Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark

Jens Langhoff-Roos

Affiliation Obstetrical Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark

Anne Kristine Nielsen

Affiliation Gynecological Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark

Kenneth J. Rothman

Affiliation Research Triangle Institute, Research Triangle Park, North Carolina, United States of America

Thomas Bergholt

Affiliation Department of Obstetrics & Gynecology, Hillerød Hospital, University of Copenhagen, Hillerød, Denmark

Competing Interests

The authors hereby declare that ØL/TB have read the journal's policy and have the following conflicts: ØL has received honoraria for speeches in pharmacoepidemiological issues. TB been invited to symposia's by Leo Pharma Nordic A/S that might have an interest in the submitted work in the previous 3 years. RAV, EL, JLR, AN, KJR have declared no competing interest exist. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. However due to Danish legislation data from The National Registry of Medical Products Statistics with information on individuals redeemed prescriptions can only be accessed by researchers with a contract to protect individual rights.

Author Contributions

Conceived and designed the experiments: EL RAV TB ØL KJR JLR. Analyzed the data: AKN RAV KJR. Wrote the paper: RAV EL. Full access to all study data and takes responsibility for the integrity of the data and the accuracy of the data analyses: RAV EL. Acquisition of data: RAV EL ØL TB. Critical reversion of the manuscript for important intellectual content: RAV EL ØL JLR KJR TB. Obtaining funding: ØL TB.