Associations between maternal size and health outcomes for women undergoing caesarean section: a multicentre prospective observational study (The MUM SIZE Study) by Dennis, AT, Lamb, KE, Story, D, Tew, M, Dalziel, K, Clarke, P, Lew, J, Parker, A, Hessian, E, Teale, G, Simmons, S, Casalaz, D, MUM SIZE Investigators