Respiratory symptoms in children of low birth weight.

We recorded the respiratory history by questionnaire in a 7 year old cohort of children whose birth weight was under 2000 g and an unselected reference group of local schoolchildren of the same age. Complete data were obtained in 121 low birthweight children (90% of those studied): 62 who had no neonatal respiratory illness, 25 who had oxygen treatment only, and 34 who received mechanical ventilation (of whom 10 had bronchopulmonary dysplasia). The low birthweight children were no more likely to wheeze than the reference group, but frequent and troublesome cough was significantly more common, especially among children of very low birth weight (under 1500 g) who had received neonatal respiratory treatment. Neonatal mechanical ventilation was not associated with increased symptoms when compared with neonatal oxygen treatment alone. The prevalence of cough at the age of 7 was independently associated with the level of neonatal intensive care as defined by oxygen score. Although there was no excess of wheeze in the cohort compared with the reference group, there was a weak correlation between wheeze and the neonatal oxygen score as well as with maternal smoking. Loss of schooling due to respiratory symptoms in the nine months before this study was no greater in children of low birth weight than in the reference group.