About the Authors

Ingrid Sääv

Affiliation Department of Women's and Children's Health, Division of Obstetrics and Gynaecology, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden

Olof Stephansson

Affiliations Department of Women's and Children's Health, Division of Obstetrics and Gynaecology, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden, Department of Medicine, Solna, Clinical Epidemiology Unit, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden

Kristina Gemzell-Danielsson

kristina.gemzell@ki.se

Affiliation Department of Women's and Children's Health, Division of Obstetrics and Gynaecology, Karolinska Institutet/Karolinska University Hospital, Stockholm, Sweden

Competing Interests

Kristina Gemzell-Danielsson has received honoraria for serving on medical advisory boards of Bayer Pharma AG. Thirty LNG-IUS devises were received from Bayer Pharma AG. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: KGD IS. Performed the experiments: KGD IS. Analyzed the data: KGD IS OS. Contributed reagents/materials/analysis tools: KGd IS OS. Wrote the paper: KGD IS OS. Patient recruitment: KGD IS. IUC insertions: KGD IS.