Author's response to reviews Title:Increase in prevalence of birth defects in an Arctic Russian setting from 1973 to 2011: a register-based study Authors: Vitaly A Postoev ( vpo000@post.uit.no) Evert Nieboer ( nieboere@univmail.cis.mcmaster.ca) Andrej M Grjibovski ( andrej.grjibovski@gmail.com) Jon Øyvind Odland ( jon.oyvind.odland@uit.no) Version:2Date:21 September 2014 Author's response to reviews: see over