Footnotes

• Contributors MM and COD participated in study design, protocol development, submission to research ethics committee, data collection and entry, data analysis and interpretation and drafting the manuscript. LD and EF contributed to data collection. LMC contributed to study design, supervision and review prior to submission.

• Competing interests None declared.

• Ethics approval Research Ethics Committee, National Maternity Hospital, Dublin, Ireland.

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