COVID-19 & Infant Neurodevelopment: Risks, Language Delays & Maternal Inflammation

The COVID-19 pandemic brought unprecedented disruption to daily life, and growing evidence suggests its impact extended to infant neurodevelopment. While the neuropsychiatric effects on school-aged children and adolescents—including increased rates of depression, anxiety, and post-traumatic stress—have been well-documented, the consequences for infants, whose early development relies heavily on non-verbal interaction, are only now coming into focus.

Recent research indicates a potential link between the pandemic and language development disorders in infants. A retrospective study conducted in Kobe, Japan, by Kyono et al. (2026) compared 63,703 children born between 2014-2018 and those born between April and October 2020. The study revealed a significantly higher proportion of neurodevelopmental disorders in the pandemic-born cohort (12.8% vs. 10.2%; OR 1.30 [1.16–1.46]; p < 0.001). Specifically, a greater percentage of infants born during the pandemic were not producing understandable words at 18 months. No significant differences were observed in hyperactivity, social interaction, or autonomous behaviors, suggesting language development was particularly affected.

This finding aligns with the understanding that early social interactions are crucial for attachment, cognitive development, communication, and emotional regulation. Factors such as mask-wearing, which obscures lip movements and facial expressions vital for language acquisition, and social isolation measures likely contributed to these delays.

Emerging research points to maternal inflammation during pregnancy as a potential mechanism linking COVID-19 exposure to altered fetal brain development. This process, known as maternal immune activation (MAI), can disrupt brain development and potentially contribute to disorders like autism, cognitive deficits, and schizophrenia.

Studies have shown that high concentrations of pro-inflammatory cytokines, such as interleukin-6 (IL-6), in maternal serum are associated with structural and functional changes in the newborn brain, including alterations in brain volume, connectivity of the amygdala, and the salience network. Research suggests these changes can impact cognitive abilities, impulse control, and working memory.

A recent study by Croen et al. (2026) assessed the impact of COVID-19 during pregnancy on neurodevelopmental outcomes in a Californian population. The study followed nearly 70,000 mother-child pairs, with 3.97% of mothers experiencing confirmed SARS-CoV-2 infection during pregnancy.

the study did not find a significant association between maternal COVID-19 infection and an increased risk of neurodevelopmental disorders, language delay, or motor delay. Yet, a borderline significant association was observed for autism spectrum disorders (adjusted OR 1.15 [0.96–1.39]), particularly in girls (OR 1.44 [1.05–1.97]). A trend towards higher risk of ASD was also noted when infection occurred during the first or second trimester.

These findings should be interpreted cautiously, considering the methodological limitations of the studies and the presence of confounding factors. The impact of socioeconomic factors, pandemic-related stress, and varying SARS-CoV-2 variants were not fully accounted for.

While the data remains limited and sometimes discordant, the emerging evidence suggests that a combination of environmental and social changes linked to the pandemic, alongside biological mechanisms involving maternal inflammation, may contribute to neurodevelopmental alterations in infants.

Further prospective studies with prolonged follow-up are crucial to clarify these associations and understand the long-term implications of prenatal COVID-19 exposure on child development.

1. Kyono Y, Nishiyama M, Yamaguchi H, Kawamura A, Oikawa S, Tokumoto S, Imai T, Murakami S, Nozu K, Mishina H, Nagase H. Impact of the COVID-19 pandemic on infant neurodevelopmental outcomes. BMJ Paediatr Open. 2026 Feb 3;10(1):e003832. Doi: 10.1136/bmjpo-2025-003832. PMID: 41633761; PMCID: PMC12878251.
2. Croen LA, Qian Y, Grosvenor L, Alexeeff S, Yolken R, Ames JL, Ashwood P, Kim DH, Van de Water J. SARS-CoV-2 infection during pregnancy and neurodevelopmental outcomes in early childhood. Transl Psychiatry. 2026 Feb 4;16(1):68. Doi: 10.1038/s41398-026-03818-9. PMID: 41639085; PMCID: PMC12886865.
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