[1] Univ Huddersfield, Sch Nursing & Midwifery, Sch Human & Hlth Sci, Huddersfield, W Yorkshire, England
[2] Univ Liverpool Liverpool Sch Trop Med, Ctr Maternal & Newborn Hlth, Liverpool, Merseyside, England
[3] Univ Manchester, Sch Nursing & Midwifery, Manchester, Lancs, England