Abstract
Objective
To assess the association between gestational age at birth and the risk of growth failure and respiratory symptoms at 3 years of age.
Design
Cohort study using the Japan Environment and Children’s Study database.
Patients
A total of 86 158 singleton infants born without physical abnormalities at 32–41 weeks of gestation were enrolled between January 2011 and March 2014.
Main outcome measures
Growth failure (weight <10th percentile and height <10th percentile) and respiratory symptoms (asthma and wheezing) at 3 years of age.
Methods
Logistic regression analysis was used to evaluate the risk of growth failure and respiratory symptoms in the moderately preterm, late preterm and early term groups compared with the full-term group after adjusting for socioeconomic and perinatal factors. Multiple imputation was used to reduce the attrition bias related to missing data.
Results
The respective adjusted ORs (95% CI) of growth failure and respiratory symptoms for the moderate preterm, late preterm and early term groups compared with the full-term group were as follows: weight <10th percentile, 2.29 (1.48–3.54), 1.43 (1.24–1.71) and 1.20 (1.12–1.28); height <10th percentile, 2.34 (1.59–3.45), 1.42 (1.25–1.60) and 1.15 (1.09–1.22); asthma, 1.63 (1.06–2.50), 1.21 (1.04–1.41) and 1.16 (1.09–1.23); and wheezing, 1.39 (1.02–1.90), 1.37 (1.25–1.51) and 1.11 (1.06–1.17).
Conclusion
Moderate preterm, late preterm and early term births were associated with a higher risk of growth failure and respiratory symptoms at 3 years of age than full-term births, with an inverse dose-response pattern.
Funder
the Ministry of the Environment, Japan