Screening for cerebral palsy in preterm infants: delay criteria for motor milestone attainment.

We evaluated the efficacy of various delay criteria (12.5%, 25%, 37.5%, 5%, 50% delay) for motor milestone attainment to screen a sample of 173 high-risk preterm infants with gestational age < 32 weeks who had been sequentially followed for 18 to 24 months. Sensitivities were best with 12.5% and 25% delays, but specificities and positive predictive values were relatively lower. Since societal resources for evaluation and treatment of cerebral palsy are limited, the excellent specificities (81% to 95%) and positive predictive values (48% to 85%) with 50% delay are more important than the somewhat lower sensitivities, especially since milestones involve a multistep screening process. Screening preterm infants by obtaining a history of motor milestone attainment with each child care visit, correcting for degree of prematurity, and using a 50% delay criteria is a practical, inexpensive method of identifying infants at highest risk of cerebral palsy.