Trends in incidence of cranial ultrasound lesions and cerebral palsy in very low birthweight infants 1982-93

Abstract

Aim - To evaluate the effects of changing perinatal practice on outcome in terms of cranial ultrasound appearances and subsequent cerebral palsy rates in survivors. Methods - A tertiary neonatal centre based prospective cohort study was undertaken of very low birthweight infants, in three 4 year periods: 1982-5, 1986-9, 1990-3. Rates of survival, parenchymal cerebral haemorrhage (PH), and leuco-malacia on cerebral ultrasound scans, and cerebral palsy (CP) at the age of 3 years were compared. Antenatal steroid prophylaxis and postnatal surfactant use were also compared. Results - VLBW infants (1722) were admitted over the 12 years, of whom 1268 (73.6%) were discharged home. Neonatal survival increased significantly over the three periods (69.2%, 72.9%, 79.7%; p<0.0001). PH declined from 14.9% to 10.5% (p=0.032) after 1990 as did CP rate (10.9% to 7.3%; p=0.046). The use of antenatal steroids and postnatal surfactant greatly increased during this period. Steroid use was significantly associated with increased survival (OR 3.34, 2.31-4.79), decreased PH (OR 0.44, 0.28-0.71), and decreased risk of CP in survivors (OR 0.47, 0.27-0.81) after standardising for gestation, birthweight, sex, place and mode of delivery. Similar effects for surfactant did not remain significant after steroid use had been accounted for. Conclusion - Improved survival in VLBW infants since 1990 has been accompanied by a fall in PH and subsequent CP rates in survivors. This change is most likely to be due to the greater use of antenatal steroid prophylaxis.