In this prospective, observational longitudinal study, infants will undergo clinical and growth assessment at 6 and 12 months' follow-up. Respiratory complications, such as wheezing, infections, chronic cough will be recorded along with hospital admissions and drug prescription or use.~Infants will undergo PFT with the infants in the supine position, during quiet, natural sleep, according to American Thoracic Society/European Respiratory Society recommendations with measurement of lung volumes, flow, functional residual capacity, time to peak tidal expiratory flow/expiratory time ratio (tPTEF/tE)10. Lung ultrasound will be performed to rule out lung abnormalities. After allowing adaptation to the mask, the investigators will record tidal breathing, flow volume loops for >2 minutes or >20 artifact-free breaths. Using commercially available software (Spiroware, Ecomedics), the investigators will extract tidal breathing parameters: ratio of time to reach peak tidal expiratory flow to expiratory time (tPTEF/tE), tidal volume (VT), and respiratory rate (RR). tPTEF/tE is a reproducible and reliable marker of airway obstruction, can detect severe expiratory airway obstruction in infants with respiratory complaints and is associated with subsequent wheezing in infancy.~Appropriate statistical methods will be used to describe clinical characteristics of patients and compare groups (T-test, Mann-Whitney test, chi-squared test, multivariate analysis, mixed models depending on data distribution - evaluated with Shapiro-Wilk test - and data characteristics).
Study outcomes and endpoints:~Primary outcome: to assess clinical characteristics of infants with confirmed COVID-19 infection at birth and to evaluate long-term respiratory consequences of neonatal COVID-19 infection.~Secondary outcome: to evaluate the prevalence and natural history of lung function impairment among infants with confirmed COVID-19 compared to infants with no history of COVID-19. To this end, infants will undergo pulmonary function testing (PFT) with the Exhalyzer D device (Eco Medics, Switzerland).