Footnotes

• Contributors AH analysed the data and wrote the letter. NE reviewed the data, helped with interpretation and edited the final draft. CM helped collate the data, provide advice on interpretation and reviewed the final draft. MB is a statistician who commented on mathematical and statistical aspects of the letter and reviewed and edited the final draft. PDG had the idea for the study, collated the data, reviewed the analysis and provided advice and edited the final copy of the letter.

• Competing interests None declared.

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

• Data sharing statement There is no additional data to report with relation to the questions that were asked of obstetricians in fetal maternal units.

• Patient consent for publication Not required.