Association Between COVID-19 Exposure Duration on Receptive and Expressive Language Development in Preschool Children

<b>Background/Objectives</b>: The COVID-19 pandemic substantially altered children's daily experiences, limiting social interactions, which are critical for language development. This study aims to explore how the pandemic influenced receptive and expressive language abilities in children under six years, focusing on the impact of exposure duration and differences with the pandemic period. <b>Methods</b>: This retrospective cross-sectional study reviewed 189 children assessed for language delay at our outpatient clinic between 2018 and 2021. Only children evaluated using the Sequenced Language Scale for Infants or the Preschool Receptive-Expressive Language Scale were included. Participants were categorized by assessment period: pre-COVID (2018-2019), acute-COVID (2020), and chronic-COVID (2021), and by age (toddlers vs. preschoolers). Linear regression assessed the relationship between pandemic exposure duration and language scores; non-parametric tests compared groups. <b>Results</b>: During the acute-COVID period, longer exposure was associated with lower receptive and expressive percentile scores. In preschoolers, receptive scores were significantly lower in the chronic-COVID group than in the pre-COVID group, while expressive scores were lower in the chronic-COVID group than in the acute-COVID group. <b>Conclusions</b>: Prolonged exposure to the pandemic environment was associated with measurable delays in both receptive and expressive language development, especially in preschoolers. The results suggest that pandemic restrictions can hinder children's language acquisition, indicating the need to strengthen early screening and provide timely interventions to support their developmental recovery.