Predicting neurosensory disabilities at two years of age in a national cohort of extremely premature infants

Abstract

Background: Extreme prematurity carries a high risk of neurosensory disability.

Aims: Examine which information obtained pre-, peri- and postnatally may be predictive of neurosensory disabilities at 2 years of age.

Study design: Prospective observational study of all infants born in Norway in 1999 and 2000 with gestational age (GA) 22-27 completed weeks or birth weight (BW) of 500-999 g.

Outcome measures: Incidence of neurosensory disabilities.

Results: Of 373 surviving children, 30 (8%) had major neurosensory disabilities (26 CP, 6 blind, 3 deaf), and a further 46 (12%) had minor visual or hearing disabilities. The rate of major neurosensory disabilities was 19 of 99 (19%) for children with GA 23-25 vs. 8 of 189 (4%) for GA 26-27 weeks (p<0.001). In a multivariable model, only morbidities detected in the neonatal intensive care unit (NICU) were associated with major neurosensory disabilities; adjusted odds ratios (95% confidence intervals) were 68.6 (18.7, 252.2) for major abnormalities on cerebral ultrasound, 6.8 (1.7, 27.4) for retinopathy of prematurity (ROP) grade>2, 3.2 (1.0, 9.7) for ROP grade 1-2, 6.5 (1.9, 22.3) for prolonged use (> or = 21 days) of steroid treatment for lung disease and 3.1 (1.0, 9.4) for clinical chorioamnionitis. The visual outcome was strongly related to the degree of ROP (p<0.001), and all who had a normal hearing screen in the NICU had normal hearing at 2 years.

Conclusion: NICU morbidities, rather than GA or intrauterine growth are the significant predictors of major neurosensory disabilities among extreme prematurity surviving to discharge from the NICU.