[1] Kenyatta Natl Hosp, Lugina Afr Midw Res Network, Nairobi, Kenya
[2] Univ Liverpool Liverpool Sch Trop Med, Ctr Childbirth, Dept Int Publ Hlth, Womens & Newborn Hlth, Liverpool, England
[3] Univ Nairobi, Sch Nursing Sci, Nairobi, Kenya
[4] Kenyatta Natl Hosp, Reprod Hlth Dept, Nairobi, Kenya
[5] Univ Liverpool Liverpool Sch Trop Med, Res Midwife, Liverpool, England