Development of airway function in infancy after preterm delivery

doi:10.1067/mpd.2002.128114

The Journal of Pediatrics

Volume 141, Issue 5, November 2002, Pages 652-658

Presented in part at the European Respiratory Society Conference, Berlin, Germany, September 22-26, 2001.

https://doi.org/10.1067/mpd.2002.128114 Get rights and content

Abstract

Objective: To assess airway function at 1 year and compare this with similar measurements made shortly after birth in preterm infants without clinical neonatal respiratory disease. Study design: Infants born at ≤36 weeks' gestational age were eligible if they required no neonatal ventilatory support and were otherwise healthy. Paired measurements of maximal expiratory flow at functional residual capacity (V′_maxFRC) were obtained ~3 weeks after birth in 24 preterm infants (gestational age [mean ± SD], 33.2 ± 2.2 weeks) and repeated at a corrected postnatal age (mean ± SD) of 57.0 ± 12.2 weeks. V′_maxFRC values were expressed as Z scores by means of sex-specific prediction equations. Results: V′_maxFRC was within normal range for all infants shortly after birth (mean ± SD Z score: −0.06 ± 0.92). By 1 year, Z scores had reduced significantly [mean (95% CI) 2nd-1st test: −1.94 (−2.27, −1.60)]. V′_maxFRC Z scores at 3 weeks were highly correlated with those at 1 year of age (Spearman correlation coefficient 0.64). Conclusions: Airway function during the first year shows considerable tracking. Even in the absence of neonatal respiratory disease, preterm delivery is associated with altered airway development during early infancy. (J Pediatr 2002;141:652-8)

Section snippets

Study population

Preterm infants were eligible for recruitment from the Neonatal Unit at the Homerton Hospital, London, if they were born at ≤36 completed weeks' gestation and required minimal ventilatory assistance (defined as intubation for <6 hours after delivery and/or supplemental oxygen for <24 hours). Infants were ineligible for recruitment if they had had any respiratory problems, including upper or lower respiratory illnesses before the first respiratory test or had coexistent congenital abnormalities.

Results

Forty infants born in the final year of the original study were recontacted, and 26 (65%) of these infants returned for respiratory function tests at approximately 1 year. Failure to follow up was primarily the result of the family moving from the district or parental concern regarding the need for sedation for tests. V′_maxFRC measurements at follow-up were unsuccessful in 2 infants because of technically unacceptable partial flow-volume curves or the child waking before data collection was

Discussion

Despite apparently normal values during the neonatal period, V′_maxFRC is significantly diminished at 1 year of age in preterm infants who have not had any neonatal respiratory problems. In addition, among this group of infants, V′_maxFRC values at 1 year are highly correlated with values obtained at 3 weeks of age, suggesting considerable tracking of airway function during the first year of life.

Although small, our study sample is representative of the original cohort. Subjects were selected on

Acknowledgements

We thank the parents who allowed their infants to take part in this study and staff of the Special Care Baby Unit, Homerton Hospital, for their support. We are grateful to Professor Tim Cole, Centre for Paediatric Epidemiology and Biostatistics, for statistical advice, and Dr Colin Feyerabend at ABS Laboratories, Medical Toxicology Unit, London, for cotinine analyses.

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Long-term expiratory airflow of infants born moderate-late preterm: A systematic review and meta-analysis
2022, eClinicalMedicine
Moderate-late preterm (MLP; 32 to <37 weeks’ gestation) birth is associated with reduced expiratory airflow during child, adolescent and adult years. However, some studies have reported only minimal airflow limitation and hence it is unclear if clinical assessment in later life is warranted. Our aim was to compare maximal expiratory airflow in children and adults born MLP with term-born controls, and with expected norms.
We systematically reviewed studies reporting z-scores for spirometric indices (forced expired volume in 1 second [FEV₁], forced vital capacity [FVC], FEV₁/FVC ratio and forced expiratory flow at 25-75% of FVC [FEF_25-75%]) from participants born MLP aged five years or older, with or without a term-born control group from 4 databases (MEDLINE, CINAHL, Embase, Emcare). Publications were searched for between the 22^nd of September 2021 to the 29^th of September 2021. A meta-analysis of eligible studies was conducted using a random effects model. The study protocol was published in PROSPERO (CRD #42021281518).
We screened 4970 articles and identified 18 relevant studies, 15 of which were eligible for meta-analysis (8 with term-born controls and 7 without). Compared with controls, MLP participants had lower z-scores (mean difference [95% confidence interval] I²) for FEV₁: -0.22 [-0.35, -0.09] 49.3%, FVC: -0.23 [-0.4, -0.06] 71.8%, FEV₁/FVC: -0.11 [-0.20 to -0.03] 9.3% and FEF_25-75%: -0.27 [-0.41 to -0.12] 21.9%. Participants born MLP also had lower z-scores, on average, when compared with a z-score of 0 (mean [95% CI] I²) for FEV₁: -0.26 [-0.40 to -0.11] 85.2%, FVC: -0.18 [-0.34 to -0.02] 88.3%, FEV₁/FVC: -0.24 [-0.43 to -0.05] 90.5% and FEF_25-75%: -0.33 [-0.54 to -0.20] 94.7%.
Those born MLP had worse expiratory airflows than those born at term, and compared with norms, although reductions were modest. Clinicians should be aware that children and adults born MLP may be at higher risk of obstructive lung disease compared with term-born peers.
This work is supported by grants from the National Health and Medical Research Council (Centre of Research Excellence #1153176, Project grant #1161304); Medical Research Future Fund (Career Development Fellowship to J.L.Y Cheong #1141354) and from the Victorian Government's Operational Infrastructure Support Programme. C. Du Berry's PhD candidature is supported by the Melbourne Research Scholarship and the Centre of Research Excellence in Newborn Medicine.
Development of Lung Function in Preterm Infants During the First Two Years of Life
2022, Archivos de Bronconeumologia
Citation Excerpt :
Previous results have showed a decrease in forced expiratory flows (FEF) in the first two years of life,4,5 which is related to a decrease in forced expiratory volume in the first second (FEV1) and in FEF between 25 and 75% of the forced vital capacity (FEF25–75%) in later years.6,7 Hoo et al.8 reported normal values of maximal expiratory flow at functional residual capacity (V’maxFRC) during tidal breathing in the neonatal period in preterm infants ≤36 weeks’ gestational age (GA), with a significant decrease in V’maxFRC at one year old. Fakhoury et al.9 published that during the first 3 years of life, children with BPD continue to show airflow limitation (low V’maxFRC), while FRC measurements increased over time.
It remains unclear if prematurity itself can influence post delivery lung development and particularly, the bronchial size.
To assess lung function during the first two years of life in healthy preterm infants and compare the measurements to those obtained in healthy term infants during the same time period.
This observational longitudinal study assessed lung function in 74 preterm (30 + 0 to 35 + 6 weeks’ gestational age) and 76 healthy term control infants who were recruited between 2011 and 2013. Measurements of tidal breathing, passive respiratory mechanics, tidal and raised volume forced expirations (V’maxFRC and FEF_25–75, respectively) were undertaken following administration of oral chloral hydrate sedation according to ATS/ERS recommendations at 6- and 18-months corrected age.
Lung function measurements were obtained from the preterm infants and full term controls initially at 6 months of age. Preterm infants had lower absolute and adjusted values (for gestational age, postnatal age, sex, body size, and confounding factors) for respiratory compliance and V’maxFRC. At 18 months corrected postnatal age, similar measurements were repeated in 57 preterm infants and 61 term controls. A catch-up in tidal volume, respiratory mechanics parameters, FEV_0.5 and forced expiratory flows was seen in preterm infants.
When compared with term controls, the lower forced expiratory flows observed in the healthy preterm group at 6 months was no longer evident at 18 months corrected age, suggesting a catch-up growth of airway function.
Todavía no está claro si la prematuridad por sí sola puede tener influencia en el desarrollo pulmonar tras el parto y, en particular, en el tamaño bronquial.
Valorar la función pulmonar durante los 2 primeros años de vida en lactantes pretérmino sanos y comparar las medidas con las obtenidas en lactantes nacidos a término sanos durante el mismo periodo de tiempo.
Este ensayo longitudinal observacional valoró la función pulmonar en 74 lactantes pretérmino (30 + 0 a 35 + 6 semanas de edad gestacional) y 76 lactantes nacidos a término sanos como controles, que se seleccionaron entre 2011 y 2013. Se llevaron a cabo las mediciones de la respiración corriente, la mecánica respiratoria pasiva, los flujos espiratorios forzados a volumen corriente y con insuflación previa (V’maxFRC y FEF_25-75, respectivamente) tras la sedación con hidrato de cloral siguiendo las recomendaciones de las ATS/ERS a la edad corregida de 6 y 18 meses.
Inicialmente se obtuvieron las medidas de función pulmonar de los lactantes pretérmino y los controles a término a los 6 meses de edad. Los lactantes pretérmino presentaron unos valores absolutos y ajustados (a la edad gestacional, la edad posnatal, el sexo, el tamaño corporal y los factores de confusión) menores para la distensibilidad pulmonar y la V’maxFRC. A los 18 meses de edad posnatal corregida, se repitieron las mismas mediciones en 57 lactantes pretérmino y 61 controles a término. Se observó una recuperación del volumen corriente, los parámetros de mecánica respiratoria, el FEV_0,5 y los flujos espiratorios forzados en los lactantes pretérmino.
En comparación con los controles a término, los flujos espiratorios forzados más bajos observados en el grupo de pretérminos sanos a los 6 meses no se observaron a los 18 meses de edad corregida, lo que evidencia un crecimiento de recuperación de la función de la vía respiratoria.
Exposure to moderate air pollution and associations with lung function at school-age: A birth cohort study
2019, Environment International
Adverse effects of higher air pollution levels before and after birth on subsequent lung function are often reported in the literature. We assessed whether low-to-moderate levels of air pollution during preschool-age impact upon lung function at school-age.
In a prospective birth cohort of 304 healthy term-born infants, 232 (79%) completed lung function at follow-up at six years. Using spatial-temporal models, levels of individual air pollution (nitrogen dioxide (NO₂) and ozone (O₃), particulate matter with a diameter <10 μm (PM₁₀)) were estimated for the time windows pregnancy, first up to the sixth year of life separately, and birth until follow-up at six years. Time window means were compared to World Health Organization (WHO) guideline limits. Associations of exposure windows with spirometry and body plethysmography indices were analyzed using regression models, adjusting for potential confounders. For subgroup analysis, air pollution exposure was categorized into quartiles (four groups of 52 children).
Mean NO₂ level from birth until follow-up was [mean (range)] [11.8 (4.9 to 35.9 μg/m³)], which is almost 4-times lower than the WHO suggested limit of 40 μg/m³. In the whole population, increased air pollution levels from birth until follow-up were associated with reduced lung function at six years. In the subgroup analysis, the 52 children exposed to NO₂ levels from the highest quartile during pregnancy, the first and second years of life and from birth until follow-up, had a significant decrease in forced expiratory volume in 1 s (FEV₁). Per interquartile range increase of NO₂, FEV₁ decreased by [z-score change (95% confidence interval)] [−1.07 (−1.67 to −0.47)], [−1.02 (−1.66 to −0.39)], [−0.51 (−0.86 to −0.17)] and [−0.80 (−1.33 to −0.27)], respectively. Air pollution exposure during pregnancy and childhood resulted in a non-significant decrease in lung volume at six years, as assessed by functional residual capacity measured by body plethysmography (FRC_pleth).
Our results suggest that exposure to higher NO₂ levels, which are still much lower than WHO guideline limits, especially during the sensitive period of early lung development, may be associated with reduced lung function at school-age. These findings support the concept of age and dose-dependent pollution effects on lung function in healthy school-aged children and underline the importance of pollution reduction measures.
Late Preterm Infants
2018, Avery's Diseases of the Newborn: Tenth Edition
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  Late preterm infants (34 to 37 weeks' gestation) are at risk of complications associated with prematurity. Because of their more mature appearance, there has historically been a lapse in early recognition and management of these issues.
- •
  Mortality rises with the loss of each gestational birth week before 39 weeks.
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  Late preterm infants have higher respiratory morbidity and mortality compared with full-term infants.
- •
  Late preterm infants require close monitoring for feeding issues, hypoglycemia, hyperbilirubinemia, infection, and thermoregulation in the postnatal period and until discharge.
- •
  Birth at earlier gestational ages has an impact on health and mortality beyond the neonatal period.
Late Preterm Infants
2017, Avery's Diseases of the Newborn, Tenth Edition
- •
  Late preterm infants (34 to 37 weeks' gestation) are at risk of complications associated with prematurity. Because of their more mature appearance, there has historically been a lapse in early recognition and management of these issues.
- •
  Mortality rises with the loss of each gestational birth week before 39 weeks.
- •
  Late preterm infants have higher respiratory morbidity and mortality compared with full-term infants.
- •
  Late preterm infants require close monitoring for feeding issues, hypoglycemia, hyperbilirubinemia, infection, and thermoregulation in the postnatal period and until discharge.
- •
  Birth at earlier gestational ages has an impact on health and mortality beyond the neonatal period.
Impact of premature birth on cardiopulmonary function in later life
2023, European Journal of Pediatrics

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^☆: Supported by the Foundation for the Study of Infant Death, the Dunhill Medical Trust, the Deutsche Forschungsgemeinschaft, and Portex Plc. Research at the Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust benefits from R & D funding received from the NHS Executive.

^☆☆: Reprint requests: Ah-Fong Hoo, MPhil, Portex Anaesthesia, Intensive Therapy and Respiratory Medicine Unit, Institute of Child Health and Great Ormond Street Hospital NHS Trust, 30 Guilford St, London WC1N 1EH, United Kingdom.

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Original ArticlesDevelopment of airway function in infancy after preterm delivery☆,☆☆

Abstract

Section snippets

Study population

Results

Discussion

Acknowledgements

J Pediatr

J Pediatr

Am J Obstet Gynecol

Am J Obstet Gynecol

Early Hum Dev

J Pediatr

Pulmonary function until two years of life in infants with bronchopulmonary dysplasia

Am J Respir Crit Care Med

Lung function in children of low birth weight

Arch Dis Child

Bronchopulmonary dysplasia and very low birthweight: lung function at 11 years of age

J Paediatr Child Health

Airway size and structure in the normal fetal and infant lung and the effect of premature delivery and artificial ventilation

Am Rev Resp Dis

Prematurity is associated with abnormal airway function in childhood

Pediatr Pulmonol

Effects of prematurity and intrauterine growth on respiratory health and lung function in childhood

BMJ

Pulmonary function during the first year of life in healthy infants born prematurely

Eur Respir J

Cross sectional stature and weight reference curves for the UK, 1990

Arch Dis Child

Respiratory function among preterm infants whose mothers smoked during pregnancy

Am J Respir Crit Care Med

The influence of ethnicity and gender on airway function in preterm infants

Am J Respir Crit Care Med

Measurement conditions

Forced expiratory maneuvers

Original Articles
Development of airway function in infancy after preterm delivery☆,☆☆