Respiratory Health in Adolescents Born Moderately-Late Preterm in a Community-Based Cohort.

Objectives: To determine the long-term effects of moderately-late preterm (MLP) birth on respiratory and allergic symptoms, lung function, and exercise capacity in adolescence.

Study Design: Outcome variables in this prospective cohort were prevalence of symptoms determined by International Study of Asthma and Allergies in Childhood questionnaires, lung function, and exercise measures.

Results: Response rate was 47% and did not vary importantly by background characteristics. In total, 71 children (aged 13-14 years) participated in the measurements, 37 born MLP and 34 born full term. Both groups were comparable in height, weight, and exercise activities but differed in gestational age (MLP 34 ± 1 weeks, full term 39 ± 0.9 weeks) and birth weight (MLP 2442 ± 539 g, full term 3693 ± 393 g). Adolescents born MLP reported more (dry) cough (MLP 25% vs those born full term 3%, P = .016) and hay fever (MLP 34% vs those born full term 9%, P = .015). Adolescents born MLP did not report more wheeze, dyspnea, asthma, and eczema. Most lung function measurements were within the normal range for both groups, except peak expiratory flow (MLP 86% of predicted vs those born full term 93%, P = .05) and maximum expiratory flow when 75% of the forced vital capacity has been exhaled (MLP 86% predicted vs those born full term 96% predicted, P = .06), which were at the lower limit of normal. We observed no differences between the groups in exercise parameters.

Conclusion: Moderately late preterm birth has little effect on respiratory health in adolescence. Adolescents born MLP report few symptoms, have only slightly more lung function abnormalities than those born full term, and do not differ in the maximal exercise test and in physical activity level.

Trial Registration: ISRCTN 80622320.