Listening to Mom in the NICU: effects of increased maternal speech exposure on language outcomes and white matter development in infants born very preterm

Abstract

Background Infants born very preterm (< 32 weeks gestational age (GA)) are at risk for developmental language delays. Poor language outcomes in children born preterm have been linked to neurobiological factors, including impaired development of the brain’s structural connectivity (white matter), and environmental factors, including decreased exposure to maternal speech in the neonatal intensive care unit (NICU). Interventions that enhance preterm infants’ exposure to maternal speech show promise as potential strategies for improving short-term health outcomes. Intervention studies have yet to establish whether increased exposure to maternal speech in the NICU offers benefits beyond the newborn period for brain and language outcomes. Methods This randomized controlled trial assesses the long-term effects of increased maternal speech exposure on structural connectivity at 12 months of age (age adjusted for prematurity (AA)) and language outcomes between 12 and 18 months of age AA. Study participants (N = 42) will include infants born very preterm (24–31 weeks 6/7 days GA). Newborns are randomly assigned to the treatment (n = 21) or standard medical care (n = 21) group. Treatment consists of increased maternal speech exposure, accomplished by playing audio recordings of each baby’s own mother reading a children’s book via an iPod placed in their crib/incubator. Infants in the control group have the identical iPod setup but are not played recordings. The primary outcome will be measures of expressive and receptive language skills, obtained from a parent questionnaire collected at 12–18 months AA. The secondary outcome will be measures of white matter development, including the mean diffusivity and fractional anisotropy derived from diffusion magnetic resonance imaging scans performed at around 36 weeks postmenstrual age during the infants’ routine brain imaging session before hospital discharge and 12 months AA. Discussion The proposed study is expected to establish the potential impact of increased maternal speech exposure on long-term language outcomes and white matter development in infants born very preterm. If successful, the findings of this study may help to guide NICU clinical practice for promoting language and brain development. This clinical trial has the potential to advance theoretical understanding of how early language exposure directly changes brain structure for later language learning. Trial registration NIH Clinical Trials (ClinicalTrials.gov) NCT04193579. Retrospectively registered on 10 December 2019.

Monitoring of Communication Precursors in Extremely Low Birth Weight (ELBW) Newborns by Video Analysis Method: Preliminary Results

“…A few clinical interventions for promoting healthy language development exist currently [28]. Interventions that enhance preterm infants' exposure to maternal speech are suggested as potential strategies for improving short-term health outcomes and also to reduce the risk of future delays in language development [28,29]. The results of this study suggest that the video recording technique is sensitive to change and could be used to assess the outcomes of early intervention.…”

“…Assessment of development of the communication skills precursors across a preterm infant in the first two years of life is important as it allows to provide useful reference values for prediction of developmental delay. A few clinical interventions for promoting healthy language development exist currently [28]. Interventions that enhance preterm infants' exposure to maternal speech are suggested as potential strategies for improving short-term health outcomes and also to reduce the risk of future delays in language development [28,29].…”

Investigating Relations between the NICU Speech Environment and Weight Gain in Infants Born Very Preterm

“…Studies that directly manipulate the amount of speech input using a randomized control design will be critical for determining whether care practices should be modified to enhance speech exposure during NICU hospitalization 25 .…”

Investigating relations between the NICU speech environment and weight gain in infants born very preterm

“…It may have been that infants in our study who gained more weight may have been more active or had more engaging behaviors than infants of lower weights, thus triggering more speech directed to them at bedside. Studies that directly manipulate the amount of speech input provided to preterm infants are likely to be critical for determining whether and how care practices should be modified to enhance speech exposure during NICU hospitalization 23 .…”