1. University Medical Centre; Department of Obstetrics and Gynaecology; Hanzeplein 1 Groningen Netherlands 9700 RB
2. St Jansdal Hospital; Obstetrics & Gynaecology; Wethouder Jansenlaan 90 Harderwijk Netherlands 3844 DG
3. Isala Clinics, Location Sophia; Department of Obstetrics & Gynaecology; Dr van Heesweg 2 P O Box 10400 Zwolle Netherlands 3515 BE
4. University Medical Centre Groningen; Hanzeplein 1 Groningen Netherlands 9700 RB