To determine whether motor development in premature infants varies according to sleep position, we evaluated 213 infants <1750 g birth weight enrolled in the Collaborative Home Infant Monitoring Evaluation (CHIME). At 56 weeks postconceptional age (PCA), sleep position was determined by maternal report, and the Bayley Scales of Infant Development 2nd Edition (BSID-II) were performed. Infants who slept supine were less likely than infants who slept prone to receive credit for maintaining the head elevated to 45° (p = .021), and infants who slept nonprone were less likely than prone sleepers to receive credit for maintaining the head elevated to 90° and lowering with control (p = .001). The Psychomotor and Mental Development Indices at 56 and 92 weeks PCA were not altered by usual sleep position at 56 weeks PCA. In summary, infants sleeping supine are less able to lift the head and lower with control at 56 weeks PCA, but global developmental status was unaffected. Supine sleeping has been associated with decreased risk for sudden infant death syndrome, but compensatory strategies while awake may be needed to avoid delayed acquisition of head control.
Address for reprints: Carl E. Hunt, M.D., Director, National Center on Sleep Disorders Research, National Heart, Lung, and Blood Institute, Two Rockledge Centre, Room 10038, 6701 Rockledge Drive, MSC 7920, Bethesda, MD 20892-7920; e-mail: firstname.lastname@example.org; fax: 301-480-3451.
*Presented in part at the Fifth International SIDS Conference, Rouen, France, April 1998; and at the Sixteenth Annual Meeting of the Society for Developmental and Behavioral Pediatrics, Cleveland, Ohio, September 24-28, 1998.
Acknowledgments. The Collaborative Home Infant Monitoring Evaluation (CHIME) study is supported by National Institute of Child Health and Human Development (NICHD): 29067, 29071, 28971, 29073, 29060, 29056, and 34625. The participants in the CHIME Study Group include the following: