Bilingual Exposure Does not Delay Language Development in Preterm Toddlers

Findings From 24 to 30 Months

Abstract: Objectives: The goal of this research was to compare language growth from 24 to 30 months of age among English monolingual toddlers, Spanish monolingual toddlers, and Spanish-English bilingual toddlers who were born preterm. Previous research has led to inconsistent findings about the relationship between bilingual exposure and language development for children born preterm. Based on research from other populations of children at-risk for language difficulties, we hypothesized that bilingual exposure would not worsen language difficulties among children born preterm.

Methods: Between August 2023 and March 2025, we collected measures of parent-reported vocabulary and experimenter-administered language assessments from 37 toddlers (54% female) across 3 language groups (n = 16 English monolingual toddlers; n = 16 Spanish-English bilingual toddlers; and n = 5 Spanish monolingual toddlers). We compared the 3 language groups using a Bayesian approach, which allowed us to quantify the strength of the evidence for and against our hypothesis.

Results: We found substantial evidence that Spanish-English bilingual children’s language skills were comparable with those of English monolingual toddlers at 24, 27, and 30 months of age.

Conclusions: This study adds to a growing body of evidence across multiple populations of children at-risk for language difficulties showing that when language skills are measured appropriately, there is no evidence that bilingual exposure worsens language outcomes relative to monolingual exposure. We strongly encourage clinicians to support families’ decisions about their child’s language exposure without fear that bilingual exposure will worsen language outcomes, even for children at-risk for language difficulties.

Published: September 9, 2026 (published ahead of print)

Funding: Research reported in this manuscript was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health under award number R21HD109725, which funded 100% ($443,100) of the total project costs.

Citation: Vaughn, K. A., Guttentag, C., Zucker, T., Vannucci, M., Berlanga, A., Tobon, D., Valles, G., Izaguirre, K., Herrera, E., & DeMaster, D. M. (2026). Bilingual Exposure Does not Delay Language Development in Preterm Toddlers: Findings From 24 to 30 Months. Journal of Developmental & Behavioral Pediatrics. https://doi.org/10.1097/DBP.0000000000001515