PREVALENCE AND ETIOLOGY OF NEUROLOGICAL IMPAIRMENT IN EXTREMELY LOW-BIRTH-WEIGHT INFANTS

Objective: To determine the prevalence and perinatal predictors of cer ebral palsy, intellectual impairment, visual impairment and deafness i n a cohort of extremely low birthweight (ELBW) infants at two years of age. Methodology: The study population comprised 199 of the 224 (89%) ELBW infants managed at the Mater's Mothers Hospital, Brisbane, betwe en July 1977 and February 1990 and who survived to two years. The prev alence of cerebral palsy, intellectual impairment, blindness and deafn ess was measured by clinical, psychometric and audiological assessment and the association with 24 risk factors examined. Results: Cerebral palsy occurred in 20 children (10%). Risk of cerebral palsy was associ ated with ventricular dilatation, intraventricular haemorrhage, necrot izing enterocolitis and multiple birth, though only ventricular dilata tion (OR 4.41; 95% CI 1.32-14.8) remained significant in the adjusted analysis. Intellectual impairment occurred in 20 children (10%) and wa s independently associated with ventricular dilatation (OR 15.0; 95% C I 2.2-102.8), ventilation F(1)o(2)>80% (OR 3.4; 95% CI 1.01-11.5), vag inal delivery (OR 3.5; 95% CI 1.09-11.4) and male sex (OR 6.1; 95% CI 1.67-22.3). No perinatal predictor was statistically associated with r isk of deafness. Retinopathy of prematurity (OR 38.9; 95% Cf 2.8-495.5 ) was associated with risk of later visual impairment. Conclusions: In tellectual impairment was associated with a broad range of perinatal v ariables. Cerebral palsy was associated with fewer variables, all of w hich were also associated with intellectual impairment. Neurologic inj ury was associated with male sex and multiple birth, which are not bio logical insults themselves, but may be markers of susceptibility to in jury.