[1] Neonatal Unit,
[2] City Hospital,undefined
[3] Nottingham NG5 1PB,undefined
[4] UK,undefined
[5] Manchester Children's Hospitals' NHS Trust,undefined
[6] Royal Manchester Children's Hospital,undefined
[7] Hospital Road,undefined
[8] Pendlebury,undefined
[9] Manchester M27 4HA,undefined
[10] UK,undefined
[11] Academic Division of Child Health,undefined
[12] School of Human Development,undefined
[13] University Hospital,undefined
[14] Queen's Medical Centre,undefined
[15] Nottingham NG7 2UH,undefined
[16] UK,undefined
[17] e-mail: Terence.Stephenson@nottingham.ac.uk,undefined
[18] Tel.: +44-115-9709255,undefined
[19] Fax: +44-115-9709382,undefined