title: The authors respond.
authors.affiliation: Department of Obstetrics and Gynaecology.
authors.forename: Sarka
authors.initials: S
authors.lastname: Lisonkova
authors.affiliation: Department of Obstetrics and Gynaecology.
authors.forename: Kenneth I
authors.initials: KI
authors.lastname: Lim
authors.affiliation: Department of Pediatrics University of British Columbia, Vancouver, BC.
authors.forename: Anne R
authors.initials: AR
authors.lastname: Synnes