Infant-Directed Speech From a Multidimensional Perspective: The Interplay of Infant Birth Status, Maternal Parenting Stress, and Dyadic Co-regulation on Infant-Directed Speech Linguistic and Pragmatic Features

The Combined Contributions of Newborn Stress and Parenting Stress on Toddler Language Development

OBJECTIVE

To examine the longitudinal associations between newborn neurobehavioral stress signs, maternal parenting stress, and several indices of toddler language development.

STUDY DESIGN

Participants include 202 mother-infant dyads (104 girls). We measured stress signs in neonates in the hospital at least 24 hours after birth using the Neonatal Intensive Care Unit Network Neurobehavioral Scale. At 7 months, parenting stress (competence, attachment, and role restriction) was assessed using the Parenting Stress Index. At 18 months, mothers completed the Communicative Development Inventories, which measured toddler gesturing, expressive vocabulary, and receptive vocabulary. Longitudinal path modeling was used to estimate associations between neonatal stress signs, parenting stress, and toddler language, and a model was generated for each language outcome. Child sex, birth weight, and family income were included as covariates.

RESULTS

Infants who exhibited greater neurobehavioral stress signs at birth produced significantly fewer social-communicative gestures at 18 months of age. Among infants whose mothers reported low (but not high) levels of parenting stress during the first postnatal year, newborn stress signs were negatively associated with 18-month-olds' receptive vocabulary size. Neither newborn stress signs nor parenting stress were significantly related to toddler expressive vocabulary size.

CONCLUSIONS

Our findings uncover a negative association between newborn stress signs and toddler gesturing. Furthermore, our results suggest that caregiver stress and neonatal stress signs interact to predict toddler receptive vocabulary. Taken together, these results demonstrate that some neonates who exhibit increased neurobehavioral stress signs may be at heightened risk for experiencing language difficulties. These children may benefit from additional support in infancy.

The Synergistic Effects of Preterm Birth and Parent Gender on the Linguistic and Interactive Features of Parent-Infant Conversations

PURPOSE

To investigate the language environments experienced by preterm-born infants, this study compared the linguistic and interactive features of parent-infant conversations involving 2-year-old preterm- and term-born infants. The study also explored how mother-infant and father-infant conversations may be differentially affected by preterm/term birth status.

METHOD

Twenty-two preterm-born (< 37 weeks' gestation) and 25 term-born (≥ 37 weeks' gestation) 2-year-old infants engaged in dyadic mother/father-infant free-play interactions that were transcribed to quantify the linguistic (parental volubility, speech rate, lexical diversity, and morphosyntactic complexity) and interactive (infant/parent responsiveness, turn-taking, and conversational balance) features of parent-infant conversations. Language, cognitive, socioemotional, and executive function skills were assessed via standardized tools.

RESULTS

Compared to the term group, the preterm group was characterized by lower maternal speech rate, parental lexical diversity, and parent-infant turn-taking, as well as greater mother-infant conversational balance. The preterm group presented poorer language and executive function skills when compared to the term group.

CONCLUSIONS

Both similarities and differences exist between the language environments of preterm and term groups. Similarities may be due to the partial developmental catch-up of preterm-born infants (cognitive and socioemotional skills) and parental scaffolding. Differences may partly reflect a parental adaptation to the language and executive function difficulties of preterm-born infants. These findings suggest that researchers/clinicians should appraise the language environment with respect to the unique developmental needs of preterm/term-born infants. Future research directions are provided to advance a more holistic characterization of the language environment and a deeper understanding of the developmental significance of preterm-term differences in such environments.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25021931.

Parent-infant conversations are differentially associated with the development of preterm- and term-born infants

Preterm birth is a risk factor for language difficulties. To better understand the language development of preterm-born infants, the current study investigated the concurrent associations between parent-infant conversations and the development of 22 preterm-born and 25 term-born infants at 2 years of age. Conversations occurring during mother/father-infant free-play interactions were analyzed to characterize features of parental speech (volubility, speech rate, lexical diversity, and morphosyntactic complexity) and parent-infant exchanges (parent responsiveness, turn-taking, and conversational balance). The infants' language development (receptive communication and expressive communication) and non-language development (cognitive, social-emotional, and executive function) was assessed using standardized measures. Parent-infant conversations were associated with both language and non-language development. This suggests that parent-infant conversations may support language development directly and/or through advancing non-language skills that could promote language learning. The associations between parent-infant conversations and development varied as a function of birth status (preterm or term). This finding may signal the operation of different developmental processes within preterm- and term-born groups. Finally, infant development was differentially associated with mother-infant and father-infant conversations. This may point to the distinct contributions made by mothers and fathers to the development of both preterm- and term-born infants. To optimize language outcomes, these findings indicate that families should be guided to tailor parent-infant conversations to the unique developmental needs and processes of preterm-born infants. Families should also be supported to leverage the distinct developmental contributions of mothers and fathers. Future recommendations are made regarding how to investigate the proposed preterm-term differences in language development processes and the differential developmental contribution of mothers and fathers.

Infant-Directed Speech to Preterm Infants during the First Year Postpartum: The Influence of Preterm Birth Weight and Maternal Parenting Stress

Premature birth can increase the level of parenting stress (PS), especially in the case of parents of high-risk infants (extremely low birth weight (ELBW) and very low birth weight (VLBW)). Though published research has explored how maternal PS influences early dyadic interactions, limited research has focused on infant-directed speech (IDS), and no studies have investigated the link between prematurity severity based on birth weight and maternal IDS. This study, involving 100 mother-infant dyads, categorized into 30 ELBW premature infants, 30 VLBW premature infants, and 40 full-term (FT) ones, examined the impact of preterm birth weight and maternal parenting stress on IDS features during early interactions at 3 and 9 months postpartum. Maternal input was assessed using the CHILDES system, while parenting stress was evaluated using the Parenting Stress Index-Short Form. The results revealed that high-risk conditions (ELBW preterm birth and high parenting stress) at 3 months were associated with reduced affect-salient speech and increased questioning. IDS functional patterns, specifically the proportion of affect-salient speech and questions, were influenced by both birth weight groups and parenting stress levels at 3 months but not at 9 months. These findings highlight the need to assess, within the context of prematurity, both birth weight and parenting stress in clinical practice, offering insights for developing interventions supporting positive parent-infant interactions and facilitating infant development.

The nature and structure of maternal parenting practices and infant behaviors in U.S. national and international samples

Methods

Twenty maternal parenting practices and 15 behaviors of their 5½- month-old infants in a U.S. national sample (N = 360) and 9 international samples (N = 653) were microcoded from videorecords of naturalistic interactions at home and aggregated into domains. Altogether, the samples were recruited from Argentina, Belgium, Brazil, France, Israel, Italy, Japan, Kenya, as well as the United States.

Background and Rationale

A previous test of three competing models of the nature and structure of the maternal parenting practices supported a hybrid 2 factor/6 domain model as superior to a 1-factor dimensional model and a multi-factor style model: Maternal parenting practices are structured into nurture, physical, social, didactic, material, and language domains undergirded by dyadic and extradyadic factors. Infant behaviors were organized into physical, social, exploration, nondistress vocalization, and distress communication domains. The current study sought to examine links connecting these previously identified maternal domains and factors with infant behavior domains using structural equation models.

Results

Mothers' dyadic factor is associated with infant social behaviors with mother; and mothers' extradyadic factor and encouragement of infant physical development are associated with infant exploration of their immediate physical environment and physical development. Infant distress communication (and less nondistress vocalization) is associated with more maternal nurturing.

Discussion

Mothers' parenting practices in the middle of the first year of infant life are commonly structured and adapted to specific needs and developmental tasks of infants. Evaluations of mother-infant interactions with national and international samples permit a wide yet judicious analysis of common vs. specific models of mother-infant relationships.