Recent developments in cattle breeding technology have made the mass production of in vitro fertilised (IVF) embryos a realistic possibility. One use of this technology will be the production of “designer calves” for beef, from dairy and suckler cows. The IVF embryos used for this purpose are likely to have the genetic potential for high growth rates which may result in higher birth weights. If used incorrectly, this development in embryo transfer (ET) technology may increase the incidence of dystocia and therefore reduce the welfare of both cows and calves. A better understanding of the factors involved in dystocia would enable management action to be taken before ET and during pregnancy which would minimise dystocia and maximise welfare of both cow and calf.