1 Department of Obstetrics and Gynaecology, Diakonessenhuis, Bosboomstraat 1, 3508 TG, Utrecht, the Netherlands. Electronic address: lisatrommelen@live.nl.
2 Department of Obstetrics and Gynaecology, Amphia Breda, the Netherlands.
3 Department of Obstetrics and Gynaecology, Monash University, Clayton, Australia.
4 Department of Obstetrics and Gynaecology, Diakonessenhuis, Bosboomstraat 1, 3508 TG, Utrecht, the Netherlands.