1. Nuffield Department of Primary Care Health Sciences; University of Oxford; Oxford UK
2. Balliol College; University of Oxford; Oxford UK
3. Women's Health Research Unit; Queen Mary University of London; London UK
4. Royal Free London NHS Trust; London UK
5. Neonatal Medicine; Faculty of Medicine; Imperial College London; London UK
6. Cochrane Gynaecology and Fertility Group; University of Auckland; Auckland New Zealand
7. MRC North West Hub for Trials Methodology Research; Institute of Translational Medicine; University of Liverpool; Liverpool UK