Big may be better when it comes to babies The study, published in the Federation of American Societies for Experimental Biology journal, set out to determine whether conditions in the womb that lead to a high or low birth weight, could affect a baby's genes and impact on the likelihood of disease. Dr Claire Quilter, of the University's Department of Pathology said: "These findings support the hypothesis that common long-term variation in the activity of genes established in the womb may underpin links between size at birth and risk for adult disease. If confirmed these could be important markers of optimal foetal growth and may be the first step along a path to very early disease prevention in the womb. Experts have warned that increasing numbers of very heavy newborns - dubbed "sumo babies" are being born because of rising obesity rates among mothers-to-be. One in four maternity units delivered babies weighing at least 12 lbs last year. Such large babies mean a greater risk of complications.