Parent-Training with Kangaroo Care Impacts Infant Neurophysiological Development & Mother-Infant Neuroendocrine Activity

A randomized control trial was conducted to investigate the effects of skin-to-skin, chest-to-chest contact (kangaroo care, KC) in mother-infant dyads on patterns of infant brain activity and associated mother-infant neurohormone releases. 33 mother-infant dyads participated during pregnancy (29–38 weeks gestation), at neonatal and 3-month periods. Overall, analyses indicated that: 1) infants in the KC group showed left frontal brain activation patterns (asymmetry and coherence) associated with KC training; 2) KC produced moderate to large increases in oxytocin levels; and 3) KC yielded moderate decreases in cortisol reactivity. Findings suggest KC may garner favorable neuro-maturational and neurobiological outcomes for dyads.     

Associations between mother-infant bed-sharing practices and infant affect and behavior during the still-face paradigm

Parents in the United States increasingly report bed-sharing with their infants (i.e., sleeping on a shared sleep surface), but the relationship between bed-sharing and child socioemotional outcomes are not well understood. The current study examines the links between mother-infant bed-sharing at 3 months and infant affect and behavior during a dyadic challenge task at 6 months. Further, we examine nighttime mother-infant contact at 3 months as a possible mechanism that may mediate linkages between bed-sharing and infant outcomes. Using observational data from a sample of 63 mother-infant dyads, we found that infants who bed-shared for any proportion of the observation period at 3 months displayed significantly more self-regulatory behaviors during the still-face episode of the Still-Face Paradigm (SFP) at 6 months, compared to non-bed-sharing infants. Also, infants of mothers who bed-shared for the entire observation period displayed significantly less negativity during the reunion episode than non-bed-sharing infants. There was no evidence that the relations between mother-infant bed-sharing practices and infant affect and behavior during the SFP were mediated through nighttime mother-infant contact. Results suggest that infant regulation at 6 months postpartum may vary based on early nighttime experiences, with bed-sharing potentially promoting more positive and well-regulated behavior during dyadic interaction.     

From biological rhythms to social rhythms: Physiological precursors of mother-infant synchrony

Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N = 71): high-risk preterms (HR; birth weight <1,000 g), low-risk preterms (LR; birth weight =1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was extracted from 4-hr observations and cardiac vagal tone was measured. At term age, infant orientation was tested with the Neonatal Behavior Assessment Scale. At 3 months, arousal modulation and emotion regulation were assessed, and mother-infant synchrony was computed from microanalysis of face-to-face interactions using time-series analysis. Sleep-wake amplitudes showed a developmental leap at 31 weeks gestation, followed by a shift in vagal tone at 34 weeks gestation. At term, differences among FT, LR, and HR infants were observed for biological rhythms in a linear-decline pattern. Sleep-wake cyclicity, vagal tone, newborn orientation, and arousal modulation were each uniquely predictive of mother-infant synchrony. The organization of physiological oscillators appears to lay the foundation for the infant's capacity to partake in a temporally matched social dialogue.     

The effect of mother-infant skin-to-skin contact on Ghanaian infants’ response to the Still Face Task: Comparison between Ghanaian and Canadian mother-infant dyads

The effect of mother-infant skin-to-skin contact on Ghanaian infants’ developing social expectations for maternal behavior was investigated. Infants with high and low mother-infant skin-to-skin contact experience in the infants’ first month engaged with their mothers in a Still Face Task at 6 weeks of age. Infants with high skin-to-skin contact experience, but not those with low skin-to-skin contact experience, demonstrated the still face effect with their smiles. Infants with both high and low skin-to-skin contact experience demonstrated the still face effect with their visual attention. The behaviors of the Ghanaian infants and their mothers during the task were compared to archival evidence of Canadian mother-infant dyads’ behaviors in skin-to-skin and control groups who engaged in the Still Face Task at the infant ages of 1 and 2 months. Similarities and differences between the behaviors of the mother-infant dyads in the two cultures were assessed.     

Some Personality Characteristics of the Culturally Disadvantaged

The relationship between sensitive maternal behavior and mother-infant vocalization during feedings was examined in an effort to determine this situational meaning of Ainsworth's concept of sensitivity. Ss were 28 white, middle-class mothers and their infants. Excerpts of home feedings videotaped at 6 and 9 months were coded for frequency of contingent vocal interaction and quality of vocal affect. Sensitive mothers were distinguished from insensitive mothers at each age period by differing vocal patterns. At 6 months, infants of sensitive mothers vocalized significantly less than did infants of insensitive mothers. Mothers in both groups responded to their infants' vocalizations equally as often. At 9 months, infants in both groups vocalized the same amount, while sensitive mothers vocalized more often in response to their infants than did insensitive mothers. The only significant difference in vocal affect was found in the greater positive affect among sensitive mothers at 9 months.     

Intersubjectivity,object relations theory,and empirical evidence from mother-infant interactions

The work of John Bowlby and his associates on the development of the infant's attachment to his or her parents in the second half of the first year reflects the fruitfulness of an integration of psychoanalytic insights and empirical research. In line with this approach, this paper considers the mother-infant relationship in the first few months from two perspectives: that of the British School of Object Relations and that of the theory of Intersubjectivity, set out initially within developmental psychology and, more recently, developed within systems theory. These views are considered in the light of evidence from two sources. First, a series of experimental studies is described employing disruptions to both the form and the timing of communication between 6- to 12-week-old infants and their mothers. This work illustrates the sensitivity of young infants to the quality of their interpersonal engagements and, also, the contribution of the infant to the regulation of interactions with others. Second, evidence is presented from a prospective study of the effects of maternal depression in the postnatal period on infant development. This work shows the possible longer term consequences for the infant of early disturbances in the mother-infant relationship. Infants of postnatally depressed women were found to be more insecurely attached to their mothers, were more likely to have mild behavioral problems (especially sleep disturbance), and showed poorer outcome on Object Concept tasks at 18 months. These effects occurred despite the fact that the mother had recovered from depression by 3 months postpartum.     

The early resumption of employment by mothers: Implications for parent-infant interaction

Home observations of mother-father-infant interaction and mother-infant interaction were contrasted in middle-class families in which the mother was employed or a full-time caregiver. First-born infants and their parents were observed at 3 months. The results indicate that when mother, father, and infant were together parents in the single wage-earner families provided more tactile stimulation to their babies; fathers in single wage-earner families tended to interact more with their infants than did mothers, while in dual wage-earner families mothers tended to interact more than fathers; and fathers in single wage-earner families exceeded fathers in dual wage-earner families in interactions with their infants. By contrast, mothers in the two groups showed very little difference in their interactions with their babies. No significant differences were found for maternal behavior in the three-person observation, and a single behavior differentiated between the groups in the mother-baby observation, with homemaker mothers more often making visual contact with their babies. The implications of these findings are discussed, both with respect to further research, and with regards to the development of children of employed mothers.     

Face-to-face interaction behavior across early infancy

Stability and change in mother-infant interaction behavior were assessed across early infancy. At 8 versus 4 months, the infants showed more smiling, vocalizing and motor-activity, and their mothers touched and moved their infants' limbs less often. Stability was noted only for infant distress-brow and mother's touching the infant. Although very few relationships were apparent between mother and infant behavior at 4 months, several maternal behaviors at 4 months were related to infant behaviors at 8 months, and several relationships were noted between maternal and infant behavior at 8 months.     

Mother-infant interaction and children's socio-emotional development with high- and low-risk mothers

Charting the dynamic character of mother-infant interaction requires using observational systems of sequential coding in real time. A longitudinal study was designed to approach maternal sensitivity in a more complex way using sequential analysis. The study was conducted with 20 high- and 20 low-risk mothers and their infants (aged: 3, 12 and 15 months) to examine the relation among mothers' risk status for physical abuse and their maternal interactive profiles, using micro-social sequential analyses, and the subsequent quality of attachment developed by their children at 15 months of age. Results showed significantly different timings in maternal responses in high- and low-risk groups, that the high-risk mothers were less sensitive: more intrusive and less discriminate regarding their infant's behavior. Significant differences between groups were also found after infant difficult behavior. High-risk mothers' infants were significantly more likely to develop insecure attachment. Sensitivity is proposed as a constellation of timings in early mother-infant interaction.     

Intervention for infants with brain injury: results of a randomized controlled study

A randomized clinical trail (RCT) employed a 12-month individualized cognitive/sensorimotor stimulation program to look at the efficacy of the intervention on 62 infants with suspected brain injury. The control group infants received the State-funded follow-up program provided by the Los Angeles (LA) Regional Centers while the intervention group received intensive stimulation using the Curriculum and Monitoring System (CAMS) taught by public health nurses (PHNs). The developmental assessments and outcome measures were performed at 6, 12 and 18 months corrected age and included the Bayley motor and mental development, the Home, mother-infant interaction (Nursing Child Assessment Feeding Scale (NCAFS) and Nursing Child Assessment Teaching Scale (NCATS)), parental stress and social support. At 18 months, 43 infants remained in the study. The results indicate that the intervention had minimal positive effects on the Bayley mental and motor development scores of infants in the intervention group. Likewise, the intervention did not contribute to less stress or better mother-infant interaction at 12 or 18 months although there were significant differences in the NCAFS scores favoring the intervention group at 6 months. There was a significant trend, however, for the control group to have a significant decrease over time on the Bayley mental scores. Although the sample was not large and attrition was at 31%, this study provides further support to the minimal effects of stimulation and home intervention for infants with brain injury and who may have more significant factors contributing to their developmental outcome.     

Mother-infant interactions in western Lowland Gorillas (Gorilla gorilla gorilla): spatial relationships,communication, and opportunities for social learning

This study investigated mother-infant interactions in lowland gorillas (Gorilla gorilla gorilla) with particular focus on the relative role of mothers and infants in creating situations that are potentially conducive to infant social learning. Eleven gorilla mother-infant dyads were focally observed in weekly 1-hr sessions for 12 months. Spatial relationships were affected by age as well as by ambient temperature. Although the youngest infant was encouraged by its mother to walk and climb, mothers showed little or no encouragement in other contexts. In contrast, infants were quite interested in their mothers' activities, on some occasions repeated their mother's behavior, and actively encouraged their mothers to share food, play, or follow them. These findings suggest that gorilla infants are more active than their mothers in creating situations that are potentially conducive to the acquisition of knowledge or skills.     

“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.     

Cesarean childbirth in sweden: Effects on the mother and father-infant relationship

The effects of Cesarean delivery on father-infant and mother-infant interaction were studied in a sample of 30 Swedish, two-parent families with a full-term healthy first-born infant. Fifteen infants were delivered vaginally, and 15 infants were delivered under full anesthesia by Cesarean section. The infants and parents were observed at home when the infants were 3 and 8 months old. The findings indicate that mothers of infants delivered by Cesarean section reacted less positively when they saw their infants for the first time and encountered more difficulties breastfeeding than did mothers of vaginally delivered infants. At 3 months post-partum, fathers of infants who were Cesarean-delivered participated in a greater amount of caregiving activities. There were no differences between Cesarean and vaginally delivered mothers at 3 months after delivery. At 8 months, there were no differences between the two groups (Cesarean and vaginal) on either the interview questions or on-any of the behavioral measures. Results from this study do not support reports from the USA of long-lasting effects of Cesarean delivery on parent-infant interaction. The results suggest the need to study cultural variations that surround Cesarean section delivery so as to understand in what way the subsequent parent-infant relationship is influenced by this event.     

Neonatal imitation, gaze aversion, and mother-infant interaction

A relationship between elicited imitation in neonates and social interaction has been proposed by several investigators. The present work examines if such a relationship can be found when studying neonatal imitation, gaze aversion, and mother-infant interaction. Thirty-two infants were observed at 2 to 3 days, 3 weeks, and 3 months of age. Imitation of tongue protrusion and mouth opening was assessed in all three observations. In addition, a face-to-face interaction between mother and child was included when the child reached 3 months of age. The most striking result was a negative relationship between the infants' brief gaze aversion observed at 3 months of age while interacting with their mothers and the infants' imitative reactions at 2 to 3 days, 3 weeks, and 3 months of age. Behaviorally, these patterns indicate that high-imitating infants tend to display fewer episodes of brief gaze aversion when interacting with their mothers.     

Chronic stress in the mother-infant dyad: Maternal hair cortisol,infant salivary cortisol and interactional synchrony

Stress physiology is shaped by early experience, with enduring effects on health. The relation of chronic maternal physiological stress, as indexed by hair cortisol, to infants’ stress systems and to mother-infant interaction quality has not been established. We examined maternal hair and salivary cortisol, six-month-old infants’ salivary cortisol, and mother-infant interaction in 121 mother-infant dyads. High maternal hair cortisol was related to higher infant average salivary cortisol concentration. Maternal hair cortisol and bedtime salivary cortisol were both uniquely related to infant bedtime salivary cortisol. Mothers with higher hair cortisol were more intrusive and had lower positive engagement synchrony with their infants. Maternal intrusiveness moderated the association of maternal hair cortisol and infant salivary cortisol, such that maternal hair and infant average salivary cortisol were related only when mothers were more intrusive. Maternal chronic physiological stress may upregulate infants’ developing stress systems, particularly in the context of lower mother-infant interaction quality.     

Maternally administered interventions for preterm infants in the NICU: Effects on maternal psychological distress and mother–infant relationship

Although studies have examined the effects of interventions focused on preterm infants, few studies have examined the effects on maternal distress (anxiety, depressive symptoms, post-traumatic stress symptoms, parenting stress) or parenting. This study examined the effects of the auditory–tactile–visual–vestibular (ATVV) intervention and kangaroo care (KC) on maternal distress and the mother–infant relationship compared to an attention control group.240 mothers from four hospitals were randomly assigned to the three groups. Maternal characteristics in the three groups were similar: 64.1% of ATVV mothers, 64.2% of KC mothers, and 76.5% of control mothers were African American; maternal age averaged 26.3 years for ATVV mothers, 28.1 for KC mothers, and 26.6 for control mothers; and years of education averaged 13.6 for ATVV and KC mothers, and 13.1 for control mothers. Mothers only differed on parity: 68.4% of ATVV and 54.7% of KC mothers were first-time mothers as compared to 43.6% of control mothers. Their infants had a similar mean gestational ages (27.0 weeks for ATVV, 27.2 for KC, and 27.4 for control) and mean birthweights (993 g for ATVV, 1022 for KC, and 1023 for control).Mothers completed questionnaires during hospitalization, and at 2, 6 and 12 months corrected age on demographic characteristics, depressive symptoms, state anxiety, post-traumatic stress symptoms, parenting stress, worry about child health, and child vulnerability (only at 12 months). At 2 and 6 months, 45-min videotapes of mother–infant interactions were made, and the HOME Inventory was scored. Behaviors coded from the videotapes and a HOME subscale were combined into five interactive dimensions: maternal positive involvement and developmental stimulation and child social behaviors, developmental maturity, and irritability.Intervention effects were examined using general linear mixed models controlling for parity and recruitment site. The groups did not differ on any maternal distress variable. Kangaroo care mothers showed a more rapid decline in worry than the other mothers. The only interactive dimensions that differed between the groups were child social behaviors and developmental maturity, which were both higher for kangaroo care infants. Change over time in several individual infant behaviors was affected by the interventions. When mothers reported on the interventions they performed, regardless of group assignment, massage (any form including ATVV) was associated with a more rapid decline in depressive symptoms and higher HOME scores. Performing either intervention was associated with lower parenting stress. These findings suggest that as short-term interventions, KC and ATVV have important effects on mothers and their preterm infants, especially in the first half of the first year.     

Effects of maternal postpartum depression in a well‐resourced sample: Early concurrent and long‐term effects on infant cognitive,language, and motor development

This study examined early and long‐term effects of maternal postpartum depression on cognitive, language, and motor development in infants of clinically depressed mothers. Participants were 83 mothers and their full‐term born children from the urban region of Copenhagen, Denmark. Of this group, 28 mothers were diagnosed with postnatal depression three to four months postpartum in a diagnostic interview. Cognitive, language, and motor development was assessed with the Bayley Scales of Infant and Toddler Development third edition, when the infants were 4 and 13 months of age. We found that maternal postpartum depression was associated with poorer cognitive development at infant age four months, the effect size being large (Cohen's d = 0.8) and with similar effects for boys and girls. At 13 months of age infants of clinical mothers did not differ from infants of non‐clinical mothers. At this time most (79%) of the clinical mothers were no longer, or not again, depressed. These results may indicate that maternal depression can have an acute, concurrent effect on infant cognitive development as early as at four months postpartum. At the same time, in the absence of other risk factors, this effect may not be enduring. The main weaknesses of the study include the relatively small sample size and that depression scores were only available for 35 of the non‐clinical mothers at 13 months.     

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.     

Teenage pregnancy: family syndrome?

A short term, longitudinal study was conducted in order to explore selected psychosocial characteristics of fourteen teenagers aged sixteen years or younger who became mothers, the subsequent interaction of the mother-infant dyads, and the development and attachment of their infants at twelve months. The sample was matched for socioeconomic and marital status, intellectual ability and ethnicity with non-pregnant teenagers and pregnant women twenty years or older. The subjects were given a psychological and social history test battery. The groups did not differ significantly on the personality tests. The pregnant women reported a significantly poorer daughter-father relationship than the nonpregnant controls. In a high proportion of cases it was found that their fathers were absent or ineffectual and the homes mother-ridden. The interview data suggest that a large number of the pregnancies were psychologically motivated.