The impact of the COVID-19 pandemic on respiratory morbidity during infancy: A birth-cohort study.

Objective: To evaluate the incidence of wheezing and overall respiratory morbidity in healthy infants born during the first peak of the coronavirus disease-2019 (COVID-19) pandemic, compared with infants born during the preceding year.

Methods: This was a single-center retrospective birth cohort study to compare a cohort of children born between February and March 2020 (COVID-19 group) to a control group of children born between February and March 2019 (pre-COVID-19 group). At 1 year of age, we collected respiratory data using parental and telephone questionnaires.