Birth injury as the cause of mental retardation.
Mental retardation, on initial impression, may appear to be caused by the birth process, but may be disproved by later clinical or autopsy examination. However, information often is lacking as to the basic pathology that may have been responsible for attributing the cause of the mental retardation to traumatic birth. From a 39-year period (1944 to 1983) 1146 records were evaluated at a state hospital for mentally retarded persons to determine how the intake impression compared with the final clinical and autopsy diagnoses of perinatal damage. Clinical evaluations provided some corrections of the intake diagnoses; autopsies provided more, but a combination provided the most reliable final diagnoses. Of 258 patients diagnosed as birth injury on intake, only 49.2% were confirmed by the best clinical and/or autopsy diagnoses. Although the cause of mental retardation was not ascertainable by either clinical or autopsy studies in 14.8% of cases, 31.4% were corrected to prenatal influences, and 4.6% to postnatal brain damage. Patients with perinatal cause of mental retardation usually were institutionalized at a young age and died young. If they do not require institutionalization until they are older, their life expectancy is longer, although still much less than that of normal persons.