COVID-19 Pandemic Exposure and Toddler Behavioral Health in the ECHO Program.

Importance: Studies suggest developmental concerns for infants born during the COVID-19 pandemic, but evidence on its impact on toddler behavioral and emotional well-being remains limited. Objective: To assess whether birth timing relative to the COVID-19 pandemic is associated with toddler internalizing and externalizing problems. Design, Setting, and Participants: This retrospective cohort study utilized Environmental Influences on Child Health Outcomes (ECHO) cohort data collected between September 27, 2009, and July 21, 2023. Children were divided into 3 groups: the prepandemic group, who were born and assessed before March 13, 2020; the pandemic-assessed group, who were born before March 13, 2020, but assessed after that date; and the pandemic-born group, who were born and assessed on or after March 13, 2020. Data were collected from 9 ECHO cohort sites across the United States and Puerto Rico. Exposure: The COVID-19 pandemic, designated as starting on March 13, 2020. Main Outcome and Measure: Parent-reported internalizing and externalizing symptoms on the Preschool Child Behavior Checklist (CBCL 1½-5) at age 18 to 39 months. Results: The 3438 children (mean [SD] age, 2.33 years [5.38 months]; 1770 [51.5%] male; 537 [16.2%] Black, 1722 [50.1%] Hispanic; and 1538 [44.7%] White) were divided into 3 groups: 1323 in the prepandemic group (mean [SD] age, 2.41 years [5.66 months]); 1690 in the pandemic-assessed group (mean [SD] age, 2.32 years [5.16 months]); and 425 in the pandemic-born group (mean [SD] age, 2.14 years [4.47 months]). Both the pandemic-assessed group (unadjusted β = -1.51; 95% CI, -2.27 to -0.75; adjusted β = -1.73; 95% CI, -2.48 to -0.99) and the pandemic-born group (unadjusted β = -2.03; 95% CI, -3.13 to -0.93; adjusted β = -1.90; 95% CI, -2.99 to -0.80) had lower levels of internalizing problems compared with the prepandemic (ie, historical) group. Similarly, both the pandemic-assessed (unadjusted β = -1.74; 95% CI, -2.46 to -1.02; adjusted β = -1.81; 95% CI, -2.53 to -1.09) and the pandemic-born group (unadjusted β = -3.16; 95% CI, -4.20 to -2.12; adjusted β = -3.17; 95% CI, -4.22 to -2.12) each had lower levels of externalizing problems compared with the prepandemic group. Conclusions and Relevance: In this study, toddlers with prenatal and postnatal as well as those with only postnatal COVID-19 pandemic exposure showed fewer internalizing and externalizing problems than those born and assessed prior to the onset of the pandemic. These findings underscore the need for further research to identify protective factors that may buffer the impact of the pandemic on child behavior.