Footnotes

• Collaborators Karine Lepigeon, RN Materno-fetal and Obstetrics Research Unit, Department of Obstetrics and Gynaecology University Hospital, Lausanne Switzerland.

• Contributors FD and DB conceived and designed the study, built the questionnaire and analysed the data. MdR and DB wrote the paper.

• Funding This work was supported by the Department of Obstetrics and Gynecology, Maternity, Lausanne, Switzerland. DB is also supported by the ‘Fondation Leenaards’ through the ‘Bourse pour la relève académique’, by the SNSF grant number 310030_156169/1, by the ‘Fondation Divesa’ and by the ‘Loterie Romande’.

• Competing interests None declared.

• Patient consent Obtained.

• Ethics approval The study was approved by the Ethical Committee of the University and Hospital, Lausanne, Switzerland (Protocol 04/34, date of approval 8th of January 2013).

• Provenance and peer review Not commissioned; externally peer reviewed.