| Affiliation: | 1. Department of Paediatric Epidemiology, Institute of Child Health, University of London, London WC1N 1EH, UK;2. Health Department, AIDS Programme, Generalitat de Catalunya, 0828 Barcelona, Spain;1. Department of Paediatric Epidemiology, Institute of Child Health, London WC1N 1EH, United Kingdon;2. School of Midwifery, St Mary''s Hospital, London W2 1NY, United Kingdon;1. Department of Paediatrics, University of Padova, 35128 Padova, Italy;2. Institute of Oncology, University of Padova, United Kingdom;1. MRC Clinical Trials Unit, London NW1 2DA, UK;2. Department of Pediatrics, University of Padova, Italy |
