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 leucomalacia 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.