Survival, cranial ultrasound and cerebral palsy in very low birthweight infants: 1980s versus 1990s

Objective: To determine the changes in the rates of survival, cranial ultra sound abnormalities and cerebral palsy in very low birthweight (VLBW) (birt hweight 500-1499 g) infants between the early 1980s and the early 1990s. Methodology: A cohort study of consecutive VLBW live births in one tertiary perinatal hospital during two distinct eras was pet-formed at The Royal Wo men's Hospital, Melbourne, a level-III perinatal centre. Consecutive VLBW i nfants born over the 18-month period from 1 October 1980 (n = 222), and ove r the 12-month period from 1 January 1992 (n = 202) were identified. The ma in outcome measures were the proportions of live births surviving to 5 year s of age, rates of cranial ultrasound abnormalities, and rates of cerebral palsy at 5 years of age. Results: Over the 18 months from 1 October 1980, 68% (150/222) VLBW live bi rths survived to 5 years of age. The survival rate rose substantially to 82 % (165/202) during 1992 (odds ratio 2.1, 95% confidence interval 1.4-3.2). The survival rate increased over time mon for those of 500-999 g birthweigh t than for those of 1000-1499 g birthweight. The rates of cerebroventricula r haemorrhage (CVH) were similar in live births and survivors from both era s, as were the rates of cerebral palsy (7.5% in 1980-82; 7.8% in 1992) in s urvivors seen at 5 years of age. The positive predictive value of CVH for c erebral palsy was low, but cystic periventricular leucomalacia was followed by cerebral palsy in seven of eight survivors from the 1992 cohort. Conclusions: Despite the increasing survival rate with improvements in peri natal care, including more antenatal steroid therapy and the introduction o f exogenous surfactant, the rates of CVH and of cerebral palsy in survivors have not diminished.