Respiratory function at age 8-9 years in extremely low birthweight/very preterm children born in Victoria in 1991-1992.

Our aim was to determine respiratory function at 8 years of age in extremely low birth weight (ELBW; birth weight, < 1,000 g)/very preterm (< 28 weeks of gestation) children born in the 1990s compared with normal birth weight (NBW; birth weight, >2,499 g) controls. The ELBW/very preterm subjects comprised 298 consecutive survivors with either birth weight < 1,000 g or gestational age < 28 weeks born in the state of Victoria during 1991-1992. Controls comprised 262 randomly selected NBW survivors. Respiratory function was measured on 81% (240/298) of the ELBW/very preterm children and 79% (208/262) of the NBW controls. Respiratory function variables reflecting airflow were substantially diminished in ELBW/very preterm children compared with NBW controls. Moreover, the proportions with clinically important reductions in airflow were higher in the ELBW/very preterm group (e.g., forced expired volume in 1 sec, < 75%; ELBW/very preterm, 19.7%; NBW, 2.4%; P < 0.0001). Within the ELBW/very preterm group, children who had bronchopulmonary dysplasia (BPD) in the newborn period and those who had later asthma had significantly reduced respiratory function in variables reflecting airflow. In conclusion, the abnormalities in respiratory function in ELBW/very preterm children compared with NBW subjects described in the presurfactant era persisted in the 1990s, especially in those who had BPD in the newborn period.