Objectives: Fetal growth and rapid postnatal weight gain are associated with adverse respiratory outcomes in childhood. However, the preterm-born population is less well studied. We assessed if the increased respiratory symptoms associated with altered fetal growth and infant weight gain were mediated by early factors.
Study design: We used data from our cohort of preterm- and term-born (n = 4284 and 2865) children, aged 1-10 years. Respiratory outcomes obtained from a respiratory questionnaire were regressed on measures of fetal growth and infant weight gain, defined as >0.67 SD change in fetal measurement or weight between birth and nine months of age, then adjusted for covariates. We used mediation analysis to investigate which variables were effect modifiers.
Results: Accelerated fetal growth between the 1st trimester and birth (OR 2.01; 95%CI 1.25, 2.32), and between the 2nd trimester and birth (1.60; 1.15, 2.22) was associated with increased wheeze-ever in preterm-born children. Rapid infant weight gain was associated with increased wheeze-ever (1.22; 1.02, 1.45); children born ≤32 weeks' gestation exhibiting rapid weight gain had fivefold higher risk of wheeze-ever compared to term-born without weight gain. Current maternal smoking and gestational age were identified as candidate mediating effects.
Conclusions: Our study suggested that antenatal and postnatal growth rates are important for future respiratory health in preterm-born children, and that their effects may be mediated by modifiable factors. Minimizing exposure to environmental pollutants, especially maternal tobacco smoking, may improve outcomes.
Keywords: dysanapsis; lung; prematurity.
© 2017 Wiley Periodicals, Inc.