The number of children in the U.S. who are exposed to both English and Spanish is on the rise. Bilingual expo- sure can provide sociocultural, economic, and/or cognitive benefits, and a growing body of research suggests that bilingual exposure does not negatively impact language skills, even for children at-risk for language difficul- ties. Previous research on a population of at-risk children, children born very preterm (VPT), has either excluded bilingual participants or has inadequately assessed their language skills. This has led to concerns among par- ents, clinicians, and researchers about the language development of bilingual VPT toddlers. In order to ade- quately assess the language skills of bilingual VPT toddlers, the proposed research will use language measures that assess total vocabulary across the two languages, focus on general language abilities, and were developed for bilingual children. Language skills will be considered in the context of other environmental and neurological factors, such as the quality and quantity of language exposure and neuroplasticity. The central hypothesis of the current study is that neuroplasticity allows the brain to adapt to a bilingual environment, and when controlling for quality and quantity of language exposure, bilingual exposure does not negatively impact language development following preterm birth. Data for this project will be collected from Spanish-English bilingual toddlers (n = 60) and monolingual (n = 60) toddlers born VPT (<32wks gestation) and their primary caregivers when the toddlers are 24-months-old (adjusted for prematurity) and again three and six months later. Families will be recruited from local pediatric clinics in the Texas Medical Center. Participation will take place in the toddler’s home at each timepoint and will include parent questionnaires, a video recording of a parent-child interaction, and a researcher- led standardized language assessment. We will compare bilingual and monolingual VPT toddlers on child lan- guage outcomes (Aim 1) and the relationship between child language outcomes and cumulative risk factors (i.e., quality and quantity of language exposure and neurodevelopmental factors; Aim 2). We hypothesize that when language abilities of bilingual and monolingual VPT children are measured appropriately, bilingual VPT children will be comparable to monolingual VPT children in their language abilities. We also hypothesize that risk factors for language difficulties will be similar for bilinguals and monolinguals. If our results support these hypotheses, parents and clinicians can rest assured that bilingual exposure is not detrimental to language development fol- lowing VPT birth. If our results do not support these hypotheses, we will identify specific differences in language development and risk factors for bilingual compared to monolingual VPT toddlers. The proposed research is innovative because it considers the unique development of bilingual VPT children and because it uses a Bayes- ian analysis approach to consider the strength of evidence that bilingual and monolingual language development is similar. This research will have a positive impact by providing the knowledge parents and clinicians require to evaluate the risks and benefits of bilingual exposure for VPT toddlers.

The proposed research is relevant to public health because approximately 10% of infants are born very preterm (VPT), which puts them at risk for lifelong health and neuropsychological problems, including language difficulties. Existing research on language development following VPT birth has left out or inadequately assessed the increasing number of children in the U.S. who are being raised in Spanish-English bilingual environments. Completion of this project will provide parents, clinicians, and researchers with the basic knowledge they need to make informed decisions about bilingual language development following VPT birth, which is relevant to NICHD’s mission to enhance the lives of children and adolescents and optimize abilities for all.