Province-Based Study of Neurologic Disability Among Survivors Weighing 500 Through 1249 Grams at Birth

Abstract

Background. As the mortality of children weighing 500 through 1249 g at birth decreases, the published rates of neurologic disability among survivors have caused concern. Outcome information from a province-based study in which perinatal/neonatal regional care is well developed and includes high-risk identification, early referral, organized transport, and outreach education, provides data from a Canadian source for comparison with epidemiologic reports.

Methods. Neurologic disability rates among 2- to 3-year-old survivors weighing 500 through 1249 g at birth is provided based on all live births/neonatal survivors/1-year survivors born in Alberta, Canada to Alberta residents in 1990.

Results. Corrected survival to 1-year was 163 of 229 or 71% of live births of the total group weighing 500 through 1249 g. Of 168 live births, 143 or 85% weighing 750 through 1249 g, free from lethal anomalies, survived. Based on 1-year survival, disability rates were: cerebral palsy, 67/1000; vision loss (acuity in the best seeing eye after correction, <20/60), 12/1000; neurosensory hearing loss (loss of ≥30 dB binaurally), 12/1000; and trainable/profound mental retardation, 18/1000. No survivor had a convulsive disorder. No vision loss or mental retardation as defined by this study occurred in survivors of ≥750 g. All children with cerebral palsy were or were projected to become ambulatory.

Conclusions. Neurologic disability among small preterm surviving infants can occur less frequently than suggested by published reports. We believe this provincial study supports the value of well developed regional perinatal programs.