Evaluation of Long-term Respiratory Complications in Infants With Perinatal COVID-19: a Pilot Study.

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).