Statistics published in the New England Journal of Medicine in 2005 reveal the risk associated with being born very prematurely (i.e., before 25 weeks of gestation). Fifty percent of these children, when evaluated at the age of two and a half, had disabilities, and a quarter of them had severe disabilities. At age six and a half, 22 percent had a severe disability, such as an inability to walk caused by cerebral palsy, very low cognitive ability, blindness or deafness. Another 24 percent had moderate disabilities, including IQs in the special needs range, a more moderate form of cerebral palsy, and problems with hearing or vision. Thirty-four percent had mild disabilities, such as wearing glasses or low/normal cognitive scores, while 20 percent had no problems.