Authors' reply re: The epidemiology and outcomes of women with postpartum haemorrhage requiring massive transfusion with eight or more units of red cells: a national cross‐sectional study. (January 2017) - Knight, Marian; Seeney, Frances M.; Hopkinson, Cathy; Collins, Peter W.; Collis, Rachel E.; Simpson, Nigel A. B.; Weeks, Andrew; Stanworth, Simon S.; Green, Laura