Changes in lung function between age 8 and 14 years in children with birthweight of less than 1,501 g

We set out to determine whether lung function of children with a birth weig ht of <1,501 g changed relative to expectations between the ages of 8 and 1 4 years. We hypothesized that changes in lung function may differ between t hose of birth weight above and below 1,000 g. The subjects of this study we re born in the Royal Women's Hospital, Melbourne. There were 86 consecutive survivors with birth weights <1,000 g born between January 1, 1977 and Mar ch 31, 1982, and 124 consecutive survivors with birth weights 1,000-1,500 g born between October 1, 1980 and March 31, 1982. Lung function was measure d at both age 8 and 14 years, corrected for prematurity in 78% (67/86) of t hose with birth weight <1,000 g, and in 69% (86/124) of those with birth we ight 1,000-1,500 g. Overall, lung function was similar to predicted values at both 8 and 14 yea rs of age [e.g., (forced expired volume in 1 s, FEV1% predicted) at age 8 y ears mean 88.5% (SD 14.7) and at age 14 years, mean 94.9% (SD 13.8)]. There were significant changes, mostly improvements, in lung function between ag e 8-14 years relative to predicted values: FEV1 (% predicted) increased bet ween 8-14 years of age by a mean of 6.4 (95% confidence interval, 4.4-8.3). The improvements in some lung function variables were significantly greate r in those of birth weight <1,000 g compared with those of birth weight 1,0 00-1,500 g: improvement in FEV1 (% predicted) between age 8-14 years in inf ants with birth weight <1,000 g had a mean of 10.3 (SD 13.1), and in those with birthweight 1,000-1,500 g a mean of 3.3 (SD 10.1). We conclude that lu ng function improved significantly relative to predicted values in children of birth weight <1,501 g between age 8-14 years. The improvements were gre atest in those of birth weight <1,000 g. (C) 1999 Wiley-Liss, Inc.