Effect of late preterm birth on longitudinal lung spirometry in school age children and adolescents
- Sarah J Kotecha1,
- W John Watkins2,
- Shantini Paranjothy2,
- Frank D Dunstan2,
- A John Henderson3,
- Sailesh Kotecha1
- 1Department of Child Health, School of Medicine, Cardiff University, Cardiff, UK
- 2Department of Primary Care and Public Health, School of Medicine, Cardiff University, Cardiff, UK
- 3School of Social and Community Medicine, University of Bristol, Bristol, UK
- Correspondence to Professor Sailesh Kotecha, Department of Child Health, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK;
Contributors All authors led by SK were involved in study design including hypothesis generation and execution. AJH is co-director of ALSPAC and was involved in collection of the data. FD and WJW were primarily responsible for statistical analyses. SJK and SK wrote the initial drafts of the paper which was contributed to by all authors. SK is the guarantor.
- Received 12 April 2011
- Accepted 29 July 2011
- Published Online First 27 September 2011
Background 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.
Methods 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.
Results 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 (FEV1) and forced vital capacity (FVC) were not significantly different from the term group but FEV1/FVC and forced expiratory flow at 25–75% FVC (FEF25–75%) 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 (FEV1 and FEF25–75) at both ages than those not ventilated in infancy.
Conclusions 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.
Funding The Avon Longitudinal Study of Parents and Children (ALSPAC) receives core funding from the UK Medical Research Council, the Wellcome Trust and the University of Bristol. The lung function measures were supported by a grant from the UK Medical Research Council (G0401540). SJK was partially supported by Nutricia Research Foundation.
Competing interests None.
Ethics approval This study was conducted with the approval of the ALSPAC Law and Ethics Committee and the local research ethics committees.
Provenance and peer review Not commissioned; externally peer reviewed.
Data Sharing Statement Data generated by the ALSPAC study are held as a national resource. Data are anonymised at entry and held separately from administrative data; therefore, identification of individual subjects' data is concealed from researchers. Access to data items is provided on application to the ALSPAC Executive Committee. The full ALSPAC collaboration policy, including details of data sharing arrangements, is published online at: http://www.bris.ac.uk/alspac/sci-com/collab-policy/.