History of airway disease
Children born very preterm had significantly more respiratory symptoms
than term controls (Table 1). Caregivers reported that 59/136 (43%)
children born very preterm had experienced at least one out of four
symptoms related to airflow obstruction (any history of wheezing,
exercise-induced wheezing, nocturnal cough without infection, sleep
disturbed by wheezing) compared to 12/56 (21%) children born at term
(p=0.004). Wheezing was the most common symptom, reported in 52/136
(38%) children born very preterm compared to 8/56 (14%) children born
at term (p=0.001). There were no differences in symptoms within the
preterm group between children with or without a diagnosis of BPD.
There were no associations between antenatal exposures and later airway
symptoms except that children born preterm after maternal infection or
after clinical chorioamnionitis had twice as often experienced nocturnal
wheezing (34% versus 16% for maternal infection, p=0.042, and 50.0%
versus 23.5% for chorioamnionitis, p=0.052) than children without these
exposures. There were no associations between respiratory support (CPAP
or ventilator days) in the neonatal period and airway symptoms at school
age.
A diagnosis of asthma was more common in children born very preterm than
in the term-born controls (36% versus 11%, p<0.001), but
equally common in very preterm children with or without BPD. None of the
children had any mechanical respiratory support or supplemental oxygen
at the time of the lung function study.