Stimulation of premature infants: The boundary between believing and knowing

Over the past two decades, technological and medical advances have resulted in increasing survival and decreasing morbidity for infants who are termed high risk due to prematurity and associated factors. As professionals began to turn their attention toward optimizing the long-term outcome for these infants, a number of pro̧grams collectively known as “infant stimulation” programs were developed. The design and implementation of these programs initially were based on findings from the basic sciences that indicated that environmental enrichment positively affected the immature nervous system, whereas environmental deprivation had adverse effects. Subsequent clinical research that analyzed the effects of stimulation programs for infants in high-risk nurseries has shown beneficial effects of varying types of stimulation on numerous dependent measures. Recently, however, some practitioners have cautioned against viewing these results as conclusive. This article is a review of multi-disciplinary research relevant to infant stimulation programs and includes a critical analysis of research findings and future needs. This analysis leads to the conclusion that many infant stimulation programs have been designed and implemented based on potentially invalid assumptions. Further research is needed prior to establishing what constitutes an optimal infant stimulation program.     

Face-to-face interaction in term and preterm infants

Previous research has found that mothers of preterm infants work harder in a face-to-face situation with their infants than mothers of term infants. Data have also revealed that preterm infants are less responsive than term infants in a social interaction. To date, there have been few studies that have attempted to determine the range of facial expressive cues that preterms may be emitting or the possible physiological basis for this behavior. In an attempt to investigate these questions, preterm and term infants were observed in a face-to-face situation. Prior to the session, three minutes of resting EKG was recorded. The infant's facial behavior was coded with a discrete facial action coding system. Maternal behavior was also coded. Measures of heart rate as well as short and long term variability were computed. Results revealed no differences in facial lability or in facial expressiveness between term and preterm infant. In addition, there were no differences in maternal behavior to either term or preterm. There were, however, reliable contingent relationships between facial expression of the infant and maternal behavior. In addition, there was a significant association between short term variability (vagal tone) and infant facial behavior.     

Early receptive and productive language skills in preterm and full-term 8-month-old infants

Early receptive and productive language skills were examined for preterm low birthweight infants and full-term normal birthweight infants from middle-class homes. Nineteen preterm infants and 19 full-term infants were observed in a laboratory setting at the gestationally corrected age of 8 months. To avoid the frequent confound between prematurity and low socioeconomic status, mothers of the two groups of infants were matched on educational levels. Regression analyses were used to assess the relative influence of infant cognitive skills, infant sociability, infant birth status, and the mothers' language input as possible predictors of infant receptive language and vocal behavior. Receptive language skills were associated with higher cognitive performance, greater sociability, and preterm birth. Productive language skills were associated with higher cognitive performance. On the basis of this research, the prognosis for language development in preterm infants raised in middle-class homes appears to be excellent.This research was aided by Social and Behavioral Sciences Research grant No. 12-11 from the March of Dimes Birth Defects Foundation and supported by DHHS Grant HD03352. Computing was provided by the Waisman Center Computing Facility at the University of Wisconsin-Madison. Donna Boylan, Sue DaPra, Maria Kleczewski, Michal Rubin, Susan Silverber, and Paula VanLaanan assisted with data collection.     

The influence of prematurity,maternal anxiety,and infants' neurobiological risk on mother–infant interactions

In this study, we investigated how the birth of a very low birth weight preterm (VLBW) infant influences the mother–infant interaction at 3 months. We also focused on the impact of the infant's neurobiological risk and maternal anxiety, and their interaction. The comparison of the VLBW preterm sample (n = 79) with an external full‐term sample (n = 35) showed mother–infant interactions of the families with the preterm infant to be more vocally responsive during the interaction, but less facially responsive during the interaction. Additionally, higher levels of maternal anxiety were associated with preterm infants being less facially responsive in interaction with their mother. While neurobiological risk of the infant played a part in this association, with higher risk infants also being less facially responsive, the relationship with maternal anxiety and the mother–child interaction was stronger. How these findings may influence therapeutic interventions is discussed.     

Consistency of maternal cognitions and principles across the first five months following preterm and term deliveries

The aims of this study were to examine and compare the development of parenting cognitions and principles in mothers following preterm and term deliveries. Parenting cognitions about child development, including thinking that is restricted to single causes and single outcomes (categorical thinking) and thinking that takes into account multiple perspectives (perspectivist thinking), have been shown to relate to child outcomes. Parenting principles about using routines (structure) or infant cues (attunement) to guide daily caregiving have been shown to relate to caregiving practices. We investigated the continuity and stability of parenting cognitions and principles in the days following birth to 5 months postpartum for mothers of infants born term and preterm. All parenting cognitions were stable across time. Categorical thinking increased at a group level across time in mothers of preterm, but not term, infants. Perspectivist thinking increased at a group level for first-time mothers (regardless of birth status) and tended to be lower in mothers of preterm infants. Structure at birth did not predict later structure (and so was unstable) in mothers of preterm, but not term, infants and neither group changed in mean level across time. Attunement was consistent across time in both groups of mothers. These results indicate that prematurity has multiple, diverse effects on parenting beliefs, which may in turn influence maternal behavior and child outcomes.     

“Hey mom, look at me!”

The degree to which infant and maternal characteristics were related to maternal psychological distress and play competence was examined in 40 mother preterm and full-term dyads. Measures of maternal psychological distress, self-efficacy, infant temperament, and mother-infant interaction in a play situation, were obtained at 4 months corrected for prematurity. Results revealed that maternal self-efficacy was the strongest correlate of maternal psychological distress but was not related to maternal play competence. Interaction effects for unadaptable temperament and infant behavioral involvement were found in the regressions predicting both maternal psychological distress and maternal play competence. Mothers of more adaptable and less behaviorally involved infants reported greater psychological distress and exhibited greater play competence than mothers of more adaptable and involved infants. The results suggest that a lack of concordance between mothers' perceptions of their infants' behavior and actual behavioral experiences adversely affects mothers' affect and the quality of their play interactions.     

Do early parental postnatal depression,attachment style and perceived social support affect neurodevelopmental outcomes of premature infants?

BackgroundThe birth of a premature infant is both a stressful event for both parents and associated with an increased rate of postnatal depression (PND). Additionally some mothers may have delayed feelings of attachment to their babies because of the medical procedures or possible medical complications. Social support is known as an important factor for well-being in the postnatal period. However there is scarce data about these factors for fathers. We aimed to identify the impact of parental PND, attachment style and social support on premature infant development considering the prematurity degree and risk groups.MethodsThis prospective study was conducted by including 96 infants who were born preterm. Mothers and fathers were given Edinburgh Postnatal Depression Scale (EPDS), Adult Attachment Style Scale (AASS), and Multidimensional Scale of Perceived Social Support (MSPSS) to fill out when their infants’ corrected age was 3 months. The developmental evaluation was conducted with Bayley III at the corrected 6 months and 18 months of age.ResultsPostnatal depression scores were more in mothers than fathers, the rates of secure attachment and social support were similar between mothers and fathers. Factors associated with the neurodevelopmental outcomes including prematurity degree and risk groups, EPDS, AASS and MSPSS scores were analyzed for both parents. In multivariate analysis, fathers’ depression scores were inversely associated with cognitive development (p = 0.030, R² = 0.080, B=-0.283) and mothers’ anxious/ambivalent attachment style was inversely associated with language development (p = 0.011, R² = 0.108, B=-0.329) at the age of corrected 6 months old.ConclusionsOur findings underscore that the efforts to improve developmental outcomes of premature infants should include parental well-being taking into account new fathers’ depressive symptomatology and maternal anxious/ambivalent attachment.     

Two-month-olds' attention and affective response to maternal still face: a comparison between term and preterm infants in Taiwan

Maternal still face is a robust experimental procedure designed to examine infants’ sensitivity to social contingency and reactivity to its violation. To extend earlier research on the still-face effect on term infants in Western cultures, the present study compared Taiwanese term and preterm infants’ attention and affective response to and recovery from a modified maternal still-face procedure that used an additional still-face reengagement sequence at 2 months of age (corrected age for preterm infants). Infants’ gaze and facial affect were coded from videos. Results showed that preterm infants were as sensitive as term infants to the interruption to social contingency. Both groups of infants reacted with decreased gaze and positive affect across episodes, together with a decreased latency to gaze aversion and an increased latency to positive affect. Both term and preterm infants also demonstrated a W-shaped pattern of decline-followed-by-recovery in their latency to negative affect. However, compared to term infants, preterm infants became distressed faster and stayed in a negative affective state longer after the first exposure to maternal still face. Effects of prematurity on infant attention and affect regulation were discussed. Implications of preterm infants’ heightened affective negativity to mild stress for intervention studies were also addressed.     

Cortisol reactivity and negative affect among preterm infants at 12 months during a mother-infant interaction task

The purpose of this study was to investigate correlates of preterm (PT) infant’s cortisol reactivity and the association to infant negative affect, during a mother-infant interaction procedure. Participants included 48 infants born prematurely (gestational age < 37 weeks) and their mothers, assessed when infants were 12 months old corrected for prematurity. The examined variables comprised both neonatal and environmental dimensions including maternal interactive behavior. Infant negative affect and maternal interactive behavior were assessed with a standardized mother-infant interaction task. A baseline infant saliva sample was collected before the interaction began, and a second sample after the interaction episodes ended. Results revealed that decrease of infant’s cortisol concentration was significantly associated with the exposure to more sensitive, and less intrusive maternal behaviors. However, once controlled for neonatal risk, family SES and maternal psychological distress, the associations were rendered non-significant. Although the association between cortisol reactivity and negative affect trended toward significance, maternal intrusiveness was the only significant predictor of observed infant negative affect. Findings suggest the importance of primary relational experiences on PT infants' early regulatory competencies.     

Early maternal stimulation and the development of cognitive competence and attention of preterm infants

The aim of the study was to investigate the relationship between several dimensions of maternal interactive behaviours, and cognitive development and attention in preterm infants. Of special interest was the question of whether high levels of maternal stimulation and activity may have negative consequences for the development of preterm infants. Sixty-six preterm infants and their mothers were followed longitudinally and videotaped in interaction situations at home, at the infant age of 6, 9 and 12 months. Mothers behaviours were scored on involvement, sensitive responsiveness, non-intrusiveness and level of activity. Moreover, infant cognitive status was assessed at 6, 12 and 24 months of age, using the Bayley Scales of Infant Development. Infant ability in problem solving and attention were assessed in two problem solving tasks at 18 and 24 months of age. The results showed that infant cognitive status at 12 and 24 months was best predicted by maternal involvement and infant responsiveness. No significant relationships were found between maternal interactive behaviours and infant ability in problem solving and attention. More importantly, there was no indication that high levels of maternal stimulation or intrusiveness may have a negative impact on later cognitive development and attention in preterm infants. © 1998 John Wiley & Sons, Ltd.     

Mutual touch during mother–infant face-to-face still-face interactions: Influences of interaction period and infant birth status

Contact behaviours such as touch, have been shown to be influential channels of nonverbal communication between mothers and infants. While existing research has examined the communicative roles of maternal or infant touch in isolation, mutual touch, whereby touching behaviours occur simultaneously between mothers and their infants, has yet to be examined. The present study was designed to investigate mutual touch during face-to-face interactions between mothers and their 5½-month-old fullterm (n = 40), very low birth weight/preterm (VLBW/preterm; n = 40) infants, and infants at psychosocial risk (n = 41). Objectives were to examine: (1) how the quantitative and qualitative aspects of touch employed by mothers and their infants varied across the normal periods of the still-face (SF) procedure, and (2) how these were associated with risk status. Mutual touch was systematically coded using the mother–infant touch scale. Interactions were found to largely consist of mutual touch and one-sided touch plus movement, highlighting that active touching is pervasive during mother–infant interactions. Consistent with the literature, while the SF period did not negatively affect the amount of mutual touch engaged in for mothers and their fullterm infants and mothers and their infants at psychosocial risk, it did for mothers and their VLBW/preterm infants. Together, results illuminate how both mothers and infants participate in shaping and co-regulating their interactions through the use of touch and underscore the contribution of examining the influence of birth status on mutual touch.     

Dyadic co-regulation,affective intensity and infant's development at 12 months: A comparison among extremely preterm and full-term dyads

Extremely low gestational age children (ELGA, born below 28 weeks of GA) represent the most at-risk preterm group in terms of survival, developmental sequelae and rates of impairment and cognitive delays. However, the impact of an extremely preterm birth on mother–infant co-regulation and affective intensity which may affect early infant's development has not been investigated. Based on a relational dynamic system approach, our study aimed to investigate the quality of co-regulation and affective intensity during spontaneous play interaction in 20 mother–infant ELGA dyads compared to 20 full-term (FT) dyads at 12 months (corrected age for ELGA infants). Relationships between the quality of dyadic co-regulation and the infant's level of cognitive, motor and language development were also investigated. The quality of dyadic co-regulation was assessed using the Revised Relational Coding System (R-RCS) by Fogel et al. (2003), the mothers’ and infants’ affective intensity was coded using a coding system by Lunkenheimer, Olson, Hollenstein, Sameroff, and Winter (2011). Infants’ development was assessed using the Bayley Scales (BSID-III, 2006). With respect to FT dyads, ELGA dyads were characterised by less frequent symmetric and more frequent unilateral co-regulation patterns and by less positive and more neutral affective intensity of both infants and mothers. Cognitive, motor and language scores were lower in ELGA infants than in FT infants. Symmetrical co-regulation was related to motor scores in ELGA infants, and to cognitive scores in FT infants. Our findings contribute to the literature by demonstrating the difficulties of ELGA mother–infant dyads at 12 months in sharing the symmetric co-regulation and positive affective intensity and how symmetric co-regulation is strictly related to motor development in ELGA infants. Based on these findings, intervention programmes to foster joint attention, active involvement and positive affective intensity in ELGA dyads and infants’ development in the first year of life should be designed.     

Sleep and Attachment in Preterm Infants

Infants born preterm are at elevated risk for socioemotional difficulties; however, factors contributing to this risk are largely understudied. Within the present study, we explored infant sleep as a biosocial factor that may play a role in infant socioemotional development. Within a prospective longitudinal design, we examined parent‐reported sleep patterns and observed parenting quality as predictors of infant–mother attachment in 171 infants born preterm. Using structural equation modeling, we examined main effect and moderator models linking infant sleep patterns and parenting with attachment security. Sleep patterns characterized by more daytime sleep and positive/responsive parenting predicted infant attachment security. Parent‐reported nighttime sleep patterns were unrelated to attachment in this sample of infants born preterm. These results indicate that daytime sleep and parenting quality may be important for emerging attachment relationships in infants born preterm.     

Is level of prematurity a risk/plasticity factor at three years of age?

Children born preterm have poorer outcomes than children born full-term, but the caregiving environment can ameliorate some of these differences. Recent research has proposed that preterm birth may be a plasticity factor, leading to better outcomes for preterm than full-term infants in higher quality environments. This analysis uses data from two waves of an Irish study of children (at 9 months and 3 years of age, n = 11,134 children) and their caregivers (n = 11,132 mothers, n = 9998 fathers) to investigate differences in how caregiving affects social, cognitive, and motor skills between full-term, late preterm, and very preterm children. Results indicate that parental emotional distress and quality of attachment are important for child outcomes. Both being born very preterm and late preterm continue to be risk factors for poorer outcomes at 3 years of age. Only fathers’ emotional distress significantly moderated the effect of prematurity on infants’ cognitive and social outcomes—no other interactions between prematurity and environment were significant. These interactions were somewhat in line with diathesis stress, but the effect sizes were too small to provide strong support for this model. There is no evidence that preterm birth is a plasticity factor.     

Attention development in infants and preschool children born preterm: a review

A potential mechanism that can explain preterm children's heightened risk for the development of later cognitive and behavioral problems is attention. Attention is the ability of an infant or child to orient to, to shift between and to maintain focus on events, objects, tasks, and problems in the external world, processes which are all dependent on the functioning of attentional networks in the brain. The aim of this paper is to provide a review of the literature on attention development in children born preterm during the first 4 years of life. First, research examining the differences between preterm and full-term children indicates that early attention development in infants born preterm is less optimal and that these differences increase when infants grow into toddlers. Second, studies investigating individual differences within preterm populations reveal the influence of both biological factors and environmental factors. Third, individual differences in early orienting and sustained attention have been shown to be predictive of later attentional, cognitive and behavioral functioning in children born preterm. The importance of long-term follow-up studies, with a focus on individual developmental trajectories in orienting, sustained and executive attention, is emphasized.     

Cognitive development in 7- to 24-month-old extremely/very-to-moderately/late preterm and full-term born infants: The mediating role of focused attention

The present study analyzed the links between prematurity, attention, and global cognitive performance in infancy and early childhood. At 7 months, focused attention (FA) was examined with an object examination task in 93 preterm infants (39 of them born extremely/very preterm, 54 born moderately/late preterm, and 38 infants born full-term). Global cognition was assessed at 7 and 24 months with the Bayley-II cognitive scale. Groups did not differ with respect to global cognitive performance but FA of infants born extremely/very preterm was significantly lower than in infants born moderately/late preterm. FA correlated significantly with both prematurity and cognitive performance at 7 months of age but not with global cognition in childhood. Findings point to a subtle adverse effect of prematurity on early attention and reveal evidence for the mediating role of FA on the effect of prematurity on cognition.     

Preterm outcomes research: a critical component of neonatal intensive care

While early preterm outcome studies described the lives of preterm survivors to justify the efforts required to save them, subsequent studies demonstrated their increased incidence of cerebral palsy, mental retardation, sensory impairments, minor neuromotor dysfunction, language delays, visual-perceptual disorders, learning disability and behavior problems compared to fullterm controls. Because infants born at the lower limit of viability require the most resources and have the highest incidence of neurodevelopmental disability, there is concern that resources have gone primarily to neonatal intensive care and are not available for meeting the followup, health, educational and emotional needs of these fragile infants and their families. Despite many methodological concerns, preterm outcome studies have provided insight into risk factors for and causes of CNS injury in preterm infants. Nevertheless, it remains difficult to predict neurodevelopmental outcome for individual preterm infants. Perinatal and neonatal risk factors are inadequate proxies for neurodevelopmental disability. Recent randomized controlled trials with one to five year neurodevelopmental followup have provided valuable information about perinatal and neonatal treatments. Recognizing adverse longterm neurodevelopmental effects of pharmacological doses of postnatal steroids is a sobering reminder of the need for longterm neurodevelopmental followup in all neonatal randomized controlled trials. Ongoing longterm preterm neurodevelopmental studies, analysis of changes in outcomes over time and among centers, and evaluation of the longterm safety, efficacy and effectiveness of many perinatal and neonatal management strategies and proposed neuroprotective agents are all necessary for further medical and technological advances in neonatal intensive care.     

Longitudinal changes in term and preterm infant night wakings: The role of caregiver anxious-depression

Changes in infant night waking during the first year of life are associated with individual (e.g., prematurity) and family (e.g., caregiver psychopathology) factors. This study examined the association between infant night waking and caregiver anxious-depressive symptoms during the first year of life in preterm and term infants. We considered between-person differences and within-person changes in caregiver anxious-depressive symptoms in relation to changes in infant night waking from 2- to 9-months. Racially (30.0% Black, 60.4% White, 9.5% multiracial/other) and socioeconomically (40.0% below median household income) diverse caregivers (N = 445) of full term (n = 258) and preterm (n = 187) infants were recruited from hospitals and clinics in two midwestern states. Caregivers completed measures of anxious-depression and their infant's night waking at four sampling periods (2-, 4-, 6-, and 9-months). Infant night wakings declined from 2- to 9-months. Between-person differences were observed, such that caregivers with higher average anxious-depressive symptoms or infants born full term reported more night wakings. Within-person effects of caregiver anxious-depressive symptoms were not significant. Caregiver anxious-depression is closely associated with infant night wakings. By considering a caregiver's average severity of anxious-depression, healthcare providers can more effectively plan infant sleep interventions. If caregiver anxious-depressive symptoms are ameliorated, night wakings may also decrease.     

Joint attention abilities in Brazilian preterm and full-term infants

Joint attention abilities of preterm and full-term Brazilian infants were assessed at 12- and 18-months, age corrected for prematurity. Results showed that preterm infants displayed significantly lower levels of correct responses to others’ bids for joint attention at both time-points, compared to full-term infants. Both groups improved their responding to joint attention from 12 to 18 months of age. Contrastingly, prematurity did not impact infants’ initiating joint attention behaviors, which remained stable over time for both groups. Findings were discussed in terms of the specific mental processes involved in distinct behavioural dimensions of joint attention.     

The effect of preterm birth on infant negative affect and maternal postpartum depressive symptoms: A preliminary examination in an underrepresented minority sample

ObjectiveTo examine the effect of preterm birth on maternal postpartum depressive symptoms and infant negative affect in an underrepresented minority sample.MethodParticipants were 102 mothers and their 3- to 10-month-old infants. Mothers completed the Edinburgh Postnatal Depression Scale and the Infant Behavior Questionnaire-Revised.ResultsRelative to normative samples, the current underrepresented minority sample of mostly Hispanics and Blacks displayed high rates of preterm birth (30%) and maternal postpartum depressive symptoms (17%). Preterm birth had a significant direct effect on postpartum depressive symptoms and infant negative affect. Additionally, there was an indirect effect of postpartum depressive symptoms on the relation between preterm birth and infant negative affect. Specifically, lower birth weight and gestational age predicted higher levels of depressive symptoms in the mother, and higher levels of depressive symptoms in the mother, in turn, predicted higher levels of infant negative affect.ConclusionFindings emphasize the importance of screening for postpartum depressive symptoms and infant negative affect among mothers and their preterm infants, especially among families from underrepresented minority backgrounds.