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).

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).

Inclusion Criteria:

• term infants;
• informed consent;
• history of perinatal COVID-19 (confirmed by nasopharyngeal swab tests, study group)

Exclusion Criteria:

• congenital malformations (particularly airway malformations);
• lack of informed consent

In this prospective, observational longitudinal study, infants with and without history of COVID-19 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. Pulmonary function tests will be performed during spontaneous, quiet sleep.