Neurological development up to the age of four years of extremely low birthweight infants born in Southern Finland in 1991-94.

A total of 142 infants with birthweights of less than 1000 g were examined at the age of 4 y by a child neurologist, by a neuropsychologist and by an occupational therapist in order to establish the rate of neurological disorders. A total of 57 (40%) of the children had normal neurological development, 52 (37%) had minor neurological disorders, 27 (19%) were diagnosed with cerebral palsy, and 6 (4%) were mentally retarded (IQ <71) with no motor disability. The rate of cerebral palsy was identical with the figure at age 2 y, but the rate of minor neurological disorders increased from 25% to 37%. Compared with international rates, we found a higher rate of cerebral palsy, but the incidence of minor neurological disorders corresponded with figures published previously.