[1] UCL, Inst Womens Hlth, London WC1E 6HX, England
[2] UCL, Uganda Womens Hlth Initiat, London WC1E 6HX, England
[3] Univ London Imperial Coll Sci Technol & Med, Dept Pediat & Imaging Sci, Comprehens Biomed Res Ctr, London, England
[4] London Sch Hyg & Trop Med, Med Stat Unit, London WC1, England
[5] Makerere Univ, Special Care Baby Unit, Mulago Hosp, Kampala, Uganda
[6] Inst Child Hlth, Int Perinatal Care Unit, London, England