Study shows no developmental delays in toddlers post-COVID-19 infection

While toddlers seem resilient to COVID-19, this new study highlights how socioeconomic factors, not the virus, may play a larger role in developmental outcomes.

Study: Association between SARS-CoV-2 infection before the age of two and child development. Image Credit: Nina Aleksandryuk / Shutterstock.com

A recent study published in the journal Pediatric Research evaluates the potential impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on cognitive development in children two years of age and younger.

How does COVID-19 affect children?

Initially, SARS-CoV-2 was highly virulent in adults, with children typically experiencing mild or no symptoms. However, the emergence of the SARS-CoV-2 Omicron variant has led more diverse populations to experience symptoms following infection, with respiratory symptoms and fever more frequently observed in younger populations.

Simultaneously, the incidence of coronavirus disease 2019 (COVID-19) and post-COVID-19 conditions has increased, particularly among adults and adolescents. Cognitive difficulties are widespread among individuals with long-COVID, even those who experienced mild symptoms during the infection.

Since children infected with newer SARS-CoV-2 variants are more likely to experience symptoms than children infected with previous viral strains, it is crucial to assess how cognitive function may be affected after recovery from COVID-19.

About the study

In the current study, researchers assess the impact of COVID-19 on development in children under two years of age. This study was conducted in an outpatient pediatric clinic in southern Thailand, with children between 18 and 24 months of age enrolled.

Children who were diagnosed with COVID-19 before February 2022, as well as those with epilepsy or documented developmental delays, were excluded from the analysis. The Thai version of the Ages and Stages Questionnaire (ASQ)-3 was administered during scheduled health checks.

The primary outcome was the ASQ-3 score, which assesses child development across five domains: problem-solving, personal-social, communication, fine motor, and gross motor. Caregivers evaluated items in each domain and reported the child’s ability to perform the task as “yes,” “sometimes,” or “no,” which were scored as 10, five, and zero, respectively.

Children with an ASQ-3 score of two or less and those who completed learning activities and monitored assessments close to this value were advised to undergo additional developmental assessments. COVID-19 status was confirmed if the study participant experienced symptoms or was in close contact with a COVID-19 case and tested positive for SARS-CoV-2 through the reverse-transcription polymerase chain reaction (RT-PCR) assay or antigen test.

Associations between variables were tested using Fisher’s exact or chi-squared test for categorical variables and the Mann-Whitney U test for continuous variables in the univariable analysis. Associations from categorical and continuous outcomes were further tested using logistic and quantile regression, respectively, in multivariable analyses adjusted for covariates.

Study findings

A total of 535 participants between 17 and 23 months of age were included in the current study, 45.8% of whom had a history of COVID-19. Questionnaire data were available for 336 participants, 53.6% of whom were diagnosed with COVID-19. The univariable analysis identified a significant association between COVID-19 status and socioeconomic status.

Income and education levels of primary caregivers were significantly higher in the COVID-19 group. In the COVID-19 group, approximately 97% of study participants experienced symptoms, with fever reported in over 94% of patients.

Over two-thirds of patients had upper respiratory tract infections. Only one COVID-19 patient had abnormal findings on chest radiography.

The average age at the time of SARS-CoV-2 infection was 1.3 years, whereas the median duration of infection before the assessment was 193.5 days. No significant associations were observed between COVID-19 status and ASQ-3 scores at the 18-month evaluation.

Comparatively, problem-solving scores were lower among those with a history of COVID-19 at the 24-month assessment. However, this association was not statistically significant.

Conclusions

The current study did not find evidence suggesting that SARS-CoV-2 infection in children under two years of age increases the risk of developmental delays at an average of six months post-infection.

Significant differences in socioeconomic status were observed between COVID-19 and non-COVID-19 groups. Furthermore, occupations involving co-working spaces were common among caregivers of children with COVID-19. Comparatively, caregivers of those without COVID-19 were more likely to be unemployed or business owners.

Notable limitations of the current study include the lack of data on in-utero COVID-19, probable misclassification of COVID-19, information bias since the ASQ-3 is parent-reported, and the lack of assessments for subtle neurodevelopmental changes like executive function.