1. Department of Obstetrics, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
2. Department of Medicine, University of Oxford, Oxford, UK
3. Nuffield Department of Anaesthesia, John Radcliffe Hospital, Oxford, UK
4. Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
5. Intensive Care Unit, Royal Berkshire Hospital, NHS Foundation Trust, Reading, UK
6. Fetal Maternal Medicine Unit, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
7. Queen Charlotte’s and Chelsea Hospital, Imperial College Healthcare NHS Trust, London, UK