Increased wheezing in children born at early term

Published Online: June 24, 2015

Early term births, which are defined as 37-38 weeks of gestation, have been shown to increase the risk of infants being admitted to neonatal intensive care units. Furthermore, studies of children born preterm, which is defined as less than 37 weeks of gestation, have shown increased risk of respiratory illness throughout childhood. However, there is limited data on the respiratory outcomes of children born early term. Early term birth accounts for nearly 19% of all deliveries in the UK.

In a recently published article in The Journal of Allergy and Clinical Immunology (JACI), Edwards and colleagues examine the combined effect of early term birth, mode of delivery, and family history of atopy on respiratory outcomes in children aged 1 to 10 years old. The investigators conducted a cross-sectional, population-based study of 2,845 term born children in Wales (UK), who responded to a health questionnaire. Primary outcomes were wheezing symptoms, hospital admissions, and inhaler medication use. The study demonstrated that being born early term (only 2-3 weeks before their due delivery date) has an increased risk of admission on the neonatal unit and to hospital in the first year of life. Pre-school children (<5 years of age) born early term reported more wheezing than term-born children and this was also true for school age (5–10 years of age) children.

The authors show that children born 37-38 weeks of gestation have greater respiratory symptoms, and that these symptoms are independent of mode of delivery and family history of atopy. This important data supports the recent change in the definition of term delivery to 39–41 weeks and early-term to 37–38 weeks of gestation by the American College of Obstetricians and Gynecologists. The underlying mechanisms for the increased risk of respiratory disease need to be clarified so that targeted therapy can be identified.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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