Fetal and Infant Growth and Childhood Lung Function

Background: Low birth weight is associated with an increased risk of childhood asthma. Underlying mechanisms might include developmental adaptations of the lungs and airways, and subsequently altered lung function. Aim and Objectives: We examined the associations of longitudinally measured fetal and infant growth with childhood lung function. Methods: This study among 2,911 children was embedded in a population-based prospective cohort study. Second and third trimester fetal weight growth was estimated from head and abdominal circumference, and femur length, measured by repeated ultrasounds. Infant weight was measured at birth and at ages 3, 6 and 12 months. Restricted and accelerated weight gain were defined as a negative or positive change of >0.67 standard deviation score, respectively. FEV1, FVC, and FEF75 were measured by spirometry at age 10 years. Results: Fetal weight gain was not associated with lung function. Greater infant weight gain between birth and age 3 months was associated with lower FEV1/FVC and FEF75 (Z-scores (95%CI): -0.08 (-0.13, -0.03) and -0.08 (-0.13, -0.04) per SDS increase infant weight). Fetal restricted weight gain followed by accelerated infant weight gain was associated with lower FEV1/FVC and FEF75, compared with normal fetal and infant weight gain (Z-scores: -0.25 (-0.46, -0.04) and -0.20 (-0.40, -0.00)). Combined accelerated fetal and infant weight gain was associated with lower FVC and FEV1/FVC (-0.19 (-0.36, -0.02) and -0.20 (-0.35, -0.02)). Conclusion: Accelerated weight gain in early infancy is associated with lower lung function in childhood, and this association may depend on fetal growth patterns. Early life might be a critical period for lung development and risk for asthma.