1. Department of Gynaecology and Obstetrics; Maasstad Hospital; Rotterdam the Netherlands
2. Department of Obstetrics; Erasmus Medical Centre; Rotterdam the Netherlands
3. Julius Centre for Health Sciences and Primary Care; University Medical Centre Utrecht; Utrecht the Netherlands
4. Department of Obstetrics and Gynaecology; Academic Medical Centre; Amsterdam the Netherlands
5. Stanford Prevention Research Center; Stanford University; Stanford CA USA
6. Centro Rosarino de Estudios Perinatales (CREP); Rosario Argentina
7. Sanquin Blood Supply Foundation; Rotterdam the Netherlands
8. School of Paediatrics and Reproductive Health; University of Adelaide; Adelaide SA Australia