Effect of late preterm birth on longitudinal lung spirometry in school age children and adolescents

• Published in: Thorax Vol. 67; no. 1; p. 54
• Main Authors: Kotecha, Sarah J, Watkins, W John, Paranjothy, Shantini, Dunstan, Frank D, Henderson, A John, Kotecha, Sailesh
• Format: Journal Article
• Language: English
• Published: England 01-01-2012
• Subjects: Adolescent; Child; Female; Follow-Up Studies; Forced Expiratory Volume - physiology; Gestational Age; Humans; Incidence; Lung - physiopathology; Male; Premature Birth - epidemiology; Premature Birth - physiopathology; Risk Factors; Spirometry - methods; United Kingdom - epidemiology; Vital Capacity
• ISSN: 1468-3296
• DOI: 10.1136/thoraxjnl-2011-200329

Rates of preterm birth have increased in most industrialised countries but data on later lung function of late preterm births are limited. A study was undertaken to compare lung function at 8-9 and 14-17 years in children born late preterm (33-34 and 35-36 weeks gestation) with children of similar age born at term (≥37 weeks gestation). Children born at 25-32 weeks gestation were also compared with children born at term.
All births from the Avon Longitudinal Study of Parents and Children (n=14 049) who had lung spirometry at 8-9 years of age (n=6705) and/or 14-17 years of age (n=4508) were divided into four gestation groups.
At 8-9 years of age, all spirometry measures were lower in the 33-34-week gestation group than in controls born at term but were similar to the spirometry decrements observed in the 25-32-week gestation group. The 35-36-week gestation group and term group had similar values. In the late preterm group, at 14-17 years of age forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC) were not significantly different from the term group but FEV(1)/FVC and forced expiratory flow at 25-75% FVC (FEF(25-75%)) remained significantly lower than term controls. Children requiring mechanical ventilation in infancy at 25-32 and 33-34 weeks gestation had in general lower airway function (FEV(1) and FEF(25-75)) at both ages than those not ventilated in infancy.
Children born at 33-34 weeks gestation have significantly lower lung function values at 8-9 years of age, similar to decrements observed in the 25-32-week group, although some improvements were noted by 14-17 years of age.