METHOD Ninety-six infants (49 males, 47 females) born at less than 30 weeks' gestation admitted to two tertiary hospitals in Melbourne, Australia, were assessed with the Bayley-III Motor Scale at 2 years' corrected age and were classified as suspect or definite motor impairment if they scored less than À1 or À2 standard deviations respectively, relative to the test mean. At 4 years' corrected age, children completed Movement Assessment Battery for Children -Second Edition (MABC-2); for the total motor score, cut-offs of not more than the 15th were used to classify motor development and cut-offs of not more than the 15th centile were classified as having a significant movement difficulty.
RESULTSOf the 96 children assessed at both ages, at 2 years 9% had suspect and 4% had definite motor impairment; however, by 4 years, rates had increased to 22% and 19% respectively. The specificity of the Bayley-III for motor impairments for later motor outcome was excellent (ranging from 94 to 100% for cerebral palsy [CP] and 97 to 100% for motor impairment), although the sensitivity was low (ranging from 67 to 83% for CP and 18 to 37% for motor impairment); many children with later impairment were not identified by the Bayley-III.INTERPRETATION The Bayley-III Motor Scale at 2 years underestimates later rates of motor impairment, particularly in the absence of CP at 4 years on the MABC-2 total motor score in children born at less than 30 weeks' gestational age.Preterm infants are at risk of various motor, cognitive, and behavioural difficulties in early and later childhood.1 These children may present with a range of motor dysfunctions from clumsiness to cerebral palsy (CP), which can have significant functional implications.2 Movement and motor coordination are critical components of development, aiding functions such as learning to sit and eating in infancy, to playing with friends at kindergarten, and handwriting at school.
3Perinatal complications such as low birthweight, gestational age, brain injury, and postnatal corticosteroids have all been associated with poorer motor outcomes in very preterm infants. 4 However, these perinatal complications do not account for all of the variance in motor outcomes, and other methods for identifying those children most at risk are required. Early developmental intervention programmes have demonstrated that remediation and rehabilitation improve some developmental outcomes in preterm infants.5 Therefore, structured neuromotor assessments are recommended for very preterm children throughout early childhood so that timely referral to early intervention services can occur. 6 Motor assessments play an important role in clinical and research settings for identification, classification, and diagnosis of motor dysfunction, as well as in evaluating the effectiveness of interventions. 7 The first and second editions of the Bayley Scales of Infant Development (Bayley Scales; Bayley-II) 8,9 have been used extensively to document motor development in young children for several decades. These scal...