Recurrent wheezing during the first 3 years of life in a birth cohort of moderate-to-late preterm infants.

BACKGROUND: Data addressing short- and long-term respiratory morbidity in moderate-late preterm infants are limited. We aim to determine the incidence of recurrent wheezing and associated risk and protective factors in these infants during the first 3 years of life. METHODS: Prospective, multicenter birth cohort study of infants born at 32+0 to 35+0  weeks' gestation and followed for 3 years to assess the incidence of physician-diagnosed recurrent wheezing. Allergen sensitization and pulmonary function were also studied. We used multivariate mixed-effects models to identify risk factors associated with recurrent wheezing. RESULTS: A total of 977 preterm infants were enrolled. Rates of recurrent wheezing during year (Y)1 and Y2 were similar (19%) but decreased to 13.3% in Y3. Related hospitalizations significantly declined from 6.3% in Y1 to 0.75% in Y3. Independent risk factors for recurrent wheezing during Y2 and Y3 included the following: day care attendance, acetaminophen use during pregnancy, and need for mechanical ventilation. Atopic dermatitis on Y2 and male sex on Y3 were also independently associated with recurrent wheezing. Palivizumab prophylaxis for RSV during the first year of life decreased the risk or recurrent wheezing on Y3. While there were no differences in rates of allergen sensitization, pulmonary function tests (FEV0.5 ) were significantly lower in children who developed recurrent wheezing. CONCLUSIONS: In moderate-to-late premature infants, respiratory symptoms were associated with lung morbidity persisted during the first 3 years of life and were associated with abnormal pulmonary function tests. Only anti-RSV prophylaxis exerted a protective effect in the development of recurrent wheezing.

Risk factors for bronchiolitis, recurrent wheezing, and related hospitalization in preterm infants during the first year of life.

BACKGROUND: Airway diseases are highly prevalent in infants and cause significant morbidity. We aimed to determine the incidence and risk factors for respiratory morbidity in a Spanish cohort of moderate-to-late preterm (MLP) infants prospectively followed during their first year of life. METHODS: SAREPREM is a multicenter, prospective, longitudinal study. Preterm infants born at 32-35 weeks of gestation with no comorbidities were enrolled within 2 weeks of life and followed at 2-4 weeks, 6, and 12 months of age. Multivariate mixed-models were performed to identify independent risk factors associated with (i) development of bronchiolitis, (ii) recurrent wheezing, or (iii) related hospital admissions. RESULTS: Overall, 977 preterm infants were included, and 766 (78.4%) completed follow-up. Of those, 365 (47.7%) developed bronchiolitis during the first year, 144 (18.8%) recurrent wheezing, and 48 (6.3%) were hospitalized. While low birthweight, day care attendance (DCA) and school-age siblings were significantly and independently associated with both the development of bronchiolitis and recurrent wheezing, lower maternal age increased the risk for bronchiolitis and respiratory-related hospitalizations. Lastly, mechanical ventilation was associated with a higher risk of bronchiolitis and history of asthma in any parent increased the likelihood of developing recurrent wheezing. CONCLUSIONS: In this study, several non-modifiable parameters (family history of asthma, low birthweight, need for mechanical ventilation) and modifiable parameters (young maternal age, DCA, or exposure to school-age siblings) were identified as significant risk factors for the development of bronchiolitis and recurrent wheezing during the first year of life in MLP infants.