[1] Clinical Trials Unit,Department of Obstetrics & Gynaecology, National Institute of Maternal and Child Health, College of Medicine
[2] London School of Hygiene and Tropical Medicine,Department of Chemical Pathology, College of Medicine
[3] University of Ibadan,Department of Obstetrics & Gynaecology, College of Medicine
[4] University of Ibadan,Department of Haematology, College of Medicine
[5] University of Ibadan,undefined
[6] University of Ibadan,undefined
[7] Thrombosis & Haemophilia Centre,undefined
[8] Guy’s & St Thomas’ Trust,undefined
[9] St Thomas’ Hospital,undefined