1. Department of Obstetrics and Gynecology, University of Copenhagen, Holbaek Hospital, Holbaek, Denmark;
2. Department of Obstetrics and Gynecology, University of Copenhagen, Slagelse Hospital, Slagelse, Denmark;
3. Department of Women and Child Health, Karolinska Institute, Stockholm, Sweden;
4. PFI (Production, Research and Innovation), Region Zealand, Denmark