Neurosensory outcome at 5 years and extremely low birthweight. The Victorian Infant Collaborative Study Group.

OBJECTIVE

To establish the stability of neurosensory outcome at 5 years of age compared with 2 years of age, and to determine whether the improving survival rate of extremely low birthweight (ELBW) (500-999 g) children has been accompanied by an increase in the number of severely impaired and disabled children in the community.

METHODS

A geographically determined cohort study was made of consecutive ELBW survivors born in the state of Victoria during 1985-7, and during 1979-80, inclusive. Rates of neurosensory impairments and disabilities at 2 and 5 or more years of age were measured.

RESULTS

Of 212 children surviving to 5 years of age born during 1985-7, 211 (99.5%) had been assessed at 2 years of age, and 209 (98.6%) were assessed at 5 or more years of age. Of the 208 children seen at both 2 and 5 years, 32 children had deteriorated, 23 children had improved, and 153 were unchanged, compared with their 2 year assessment. The major reason for a change in classification was an alteration in psychological test results. Compared with ELBW children born in 1979-80, those born in 1985-7 had significant reductions in hearing and intellectual impairment. The rate of severe neurosensory disability in the 1985-7 cohort was 5.7% compared with 12.4% in children born in 1979-80.

CONCLUSIONS

The age of 2 is too early to be sure of neurosensory outcome in ELBW infants. The additional survivors born in the mid 1980s, compared with the late 1970s, are free of severe neurosensory disability at 5 years of age, with no increase in the absolute number of ELBW children surviving with severe neurosensory disability.