Transient Tachypnea of the Newborn May Be an Early Clinical Manifestation of Wheezing Symptoms

Liem JJ, Huq SI, Ekuma O, Becker AB, Kozyrskyj AL. J Pediatr. 2007;151(1):29–33 PURPOSE OF THE STUDY. To identify risk factors associated with transient tachypnea of the newborn (TTN) and its possible association with wheezing symptoms in early childhood. STUDY POPULATION. Data were collected from the Population Health Research Data Repository at the Manitoba Centre for Health Policy. This was a retrospective evaluation of 12 763 children who were born at term. In this cohort, children with physician-determined bronchiolitis, acute bronchitis, chronic bronchitis, asthma, or need for prescription asthma medications were identified as having wheezing syndromes. METHODS. Children diagnosed with TTN at birth were identified, and Cox proportional hazards regression analysis for time to first event of hospitalization, physician visit, or prescription for an asthma medication up to 7 years of age was performed. Hazard ratios were compared with those of healthy newborns. RESULTS. A total of 308 (2.4%) of the study children developed TTN. Risk factors for development of TTN included maternal asthma, birth weight of ≥4500 g, male gender, and urban location. Infants with TTN at birth had a significantly increased risk of having a wheezing disorder in early childhood (adjusted hazard ratio: 1.17 [95% confidence interval: 1.02–1.34]). CONCLUSIONS. TTN is associated with the development of wheezing syndromes in early childhood. REVIEWER COMMENTS. TTN is generally believed to resolve in 2 to 5 days with no increased risk of pulmonary complications. The findings in this study suggest otherwise, with maternal asthma a risk factor for development of TTN. Nevertheless, the spectrum of wheezing disorders is broad, especially in this study where they evaluated onset of symptoms before 7 years of age, and not every young child with wheezing eventually develops childhood asthma. Additional studies to examine the association between TTN and wheezing before the age of 3 years may help determine if TTN plays a critical role in early pulmonary development.