Birthweight and Preterm Birth in Relation to Indicators of Childhood Asthma

Abstract

BACKGROUND: Early life events may have long term consequences on respiratory health including the risk of developing asthma. OBJECTIVE: To examine the independent roles of birthweight and preterm birth on childhood asthma after accounting for socioeconomic status. METHODS: A total of 989 elementary school children performed spirometry before and after a free-running exercise challenge. A subsample of 327 children underwent methacholine bronchoprovocation and allergy skin prick tests to common inhaled aeroallergens. Information on birthweight and preterm birth was obtained by parental interview. Socioeconomic status was established using parental occupation. RESULTS: After adjusting for the effects of important confounding variables, birthweight was positively associated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1); FVC increased 4.5% per kg (95% CI 1.7 to 7.4) and FEV1 4.4% per kg (95% CI 1.8 to 7.2). Birthweight was not related to exercise-induced bronchospasm or an asthma diagnosis, but airway responsiveness to methacholine increased as birthweight decreased (P=0.01). Preterm birth independent of birthweight was associated with a lower FEV 1 /FVC (-1.7%; 95% CI -2.8 to -0.5).CONCLUSIONS: Birthweight appears to be related to lung size and methacholine responsiveness while preterm birth appears to diminish airway size.

Birth size effect on pulmonary functions and atopic sensitization in preadolescence

“…There is currently interest in the role of fetal growth patterns in the inception of asthma 1 . A few studies have found a relationship between lower birthweight and asthma in children, 2,3 but most have not 4–6 . There are few data on the relationship between lower birthweight and asthma beyond late adolescence because of paucity of reliable data for individuals followed prospectively from birth to adulthood.…”

Transient early wheeze is not associated with impaired lung function in 7‐yr-old children

“…There are reports that low birthweight and maternal smoking during pregnancy may influence lung growth and therefore be associated with lower forced vital capacity (FVC) [3][4][5] and later asthma or respiratory disease [6][7][8]. Conversely, increased foetal growth was reported to be related to increased risk of asthma and atopy in childhood [9].…”

Wheezing and eczema in relation to infant anthropometry: evidence of developmental programming of disease in childhood

“…Whilst Shaheen et al . (1999) reported that among adults of the 1970 British birth cohort low birthweight was associated with diagnosed asthma and with wheezing, most other studies find no association with wheeze, atopy and weight at birth (Demissie et al ., 1997; Gregory et al ., 1999; Bolte et al ., 2004). Indeed Bolte et al .…”