Development of synchrony between activity patterns of mother–infant pair from 4 to 18 months after birth

Motor activities of interacting agents get temporally coordinated to form synchronized actions. Such activity synchrony is observed in several mammalian species and is supposed to play vital roles in human social interactions. Therefore, it has long been proposed that the activity patterns of mother and infant get temporally synchronized. However, few studies to date have empirically investigated the developmental course of such synchrony. The present study simultaneously measured motor activities of mother–infant pairs for about 3.5 consecutive days by actigraph, and investigated the developmental course of mother–infant synchrony. The multiple regression analysis revealed an increase of mother–infant synchrony from 4 to 18 months after birth, giving support to the notion that activity patterns of mother and infant mutually entrain each other through the course of development.     

Physiological measures of mother–infant interactional synchrony

Mother–infant interactional synchrony has been hypothesized to be crucial for the development of many key neurodevelopmental behaviors in infants, including speech and language. Assessing synchrony is challenging because many interactive behaviors may be subtlety, if at all, observable in overt behaviors. Physiological measures, therefore, may provide valuable physiological/biological markers of mother–infant synchrony. We have developed a multilevel measurement platform to assess physiological synchrony, attention, and vocal congruency during dynamic face-to-face mother–infant interactions. The present investigation was designed to provide preliminary data on its application in a group of 10 mother–infant dyads (20 subjects) ranging in age from 7 to 8.5 months at the time of the experimentation. Respiratory kinematics, heart rate, and vocalization were recorded simultaneously from mothers and infants during nonstructured, face-to-face interactions. Novel statistical methods were used to identify reliable moments of synchrony from cross-correlated, mother–infant respiration and to tag infant attention from heart rate deceleration. Results revealed that attention, vocal contingency, and respiratory synchrony are temporally clustered within the dyad interaction. This temporal alignment is consistent with the notion that biological synchrony provides a supportive platform for infant attention and mother–infant contingent vocalization.     

Infant–mother and infant–sibling attachment in Zambia

This study, the first in Zambia using the Strange Situation Procedure (SSP) to observe attachment relationships and the “very first” observational study of infant–sibling attachment, examined patterns of infant–mother and infant–sibling attachment, and tested their association. We included siblings who were substantially involved in caregiving activities with their younger siblings. We hypothesized that infants would develop attachment relationships to both mothers and siblings; the majority of infants would be classified as securely attached to both caregivers, and infant–mother and infant–sibling attachment would be unrelated. The sample included 88 low-income families in Lusaka, Zambia (average of 3.5 children; SD = 1.5). The SSP distributions (infant–mother) were 59% secure, 24% avoidant and 17% resistant, and 46% secure, 20% avoidant, 5% resistant and 29% disorganized for three- and four-way classifications, respectively. The infant–sibling classifications were 42% secure, 23% avoidant and 35% resistant, and 35% secure, 23% avoidant, 9% resistant and 33% disorganized for three- and four-way classifications, respectively. Infant–mother and infant–sibling attachment relationships were not associated.     

Severe disorders of the mother–infant relationship: definitions and frequency

Summary We assessed the frequency of severe disorders of the mother–infant relationship in over 200 mothers referred to services in Birmingham and Christchurch, all of whom were interviewed using the Birmingham Interview for Maternal Mental Health. 10.6% had established rejection and 14.6% threatened rejection of their infants. 28.6% had various degrees of pathological anger, which was severe in 8.3%. Rejection was strongly associated with unwanted pregnancy and lack of interaction with the foetus.     

It takes two to talk: Longitudinal associations among infant–mother attachment,maternal attachment representations,and mother–child emotion dialogues

Research on the attachment-dialogue link has largely focused on infant–mother attachment. This study investigated longitudinal associations between infant–mother attachment and maternal attachment representations and subsequent mother–child emotion dialogues (N = 50). Maternal attachment representations were assessed using the Adult Attachment Interview when children were 3 months, infant–mother attachment was assessed using the Strange Situation Procedure at 13 months, and mother–child emotion dialogues were assessed using the Autobiographical Emotional Events Dialogue at 3.5 years. Consistent with past research, the three organized categories of infant–mother attachment relationships were associated with later mother–child emotion dialogues. Disorganized attachment relationships were associated with a lack of consistent and coherent strategy during emotion dialogues. Autonomous mothers co-constructed coherent narratives with their children; Dismissing and Preoccupied mothers created stories that were less narratively organized. Although the Unresolved category was unrelated to classifications of types of mother–child discourse, mothers’ quality of contribution to the dialogues was marginally lower compared to the quality of their children’s contributions to the emotion discussion. Secure children showed highest levels of child cooperation and exploration. Autonomous mothers displayed highest levels of maternal sensitive guidance during emotion dialogues. We provide preliminary evidence for role reversal in dialogues between Preoccupied and Unresolved mothers and their children.     

Maternal depressed mood moderates the impact of infant sleep on mother–infant bonding

Parent–infant bonding has long-term consequences for the psychological wellbeing of the child. Considering the centrality of infant sleep patterns in infant–caregiver interactions in the first year of life, we propose that infant sleep patterns act as a catalyst or disruptor for mother–infant relationship, such that infant sleep patterns contribute to maternal mood, maternal sleep quality, perception of infant temperament, and her bonding experience. One hundred fifty-two Israeli mothers, of 5–8-month-old infants, responded to Internet-based questionnaires regarding their sleep, their mood, their infant’s sleep, the infant’s temperament, and their bonding experience. Eight percent of the mothers reported clinically significant depression, while 67 % reported significant sleep difficulties. Infant sleep difficulties correlated with maternal mood and sleep quality, infant fussiness, and bonding. Structural equation modeling demonstrated that maternal sleep partially mediated the relationship between infant sleep and maternal mood. Additionally, 22 % of the variance in bonding was explained by infant sleep problems and temperament. Notably, maternal depression moderated this effect such that infant sleep problems correlated with bonding only in those mothers who were depressed. The results suggest that infant sleep is a vector by which maternal cognitions and mood are transmitted to her child, with long-term implications for psychological development.     

Delusions related to infant and their association with mother–infant interactions in postpartum psychotic disorders

Summary The relationship between mother infant interactions and psychopathology in postpartum psychotic disorders has been recognised as being clinically important, however data in the field is sparse. The current study had two aims – firstly, to study the prevalence and nature of delusions towards the infant among mothers with postpartum onset severe mental illness and secondly, to study the association between delusional symptoms towards the infant and mother infant interactions. 108 consecutive women with onset of severe mental illness in the postpartum, who were admitted to an inpatient psychiatric unit in South India over a two-year period, were systematically assessed for presence of delusions related to the infant, using the Kannada version of the Birmingham Interview for Maternal Mental Health. Fifty-three percent of subjects reported delusions related to the infant, with 34% reporting more than one delusion. Mothers with infant related persecutory delusions were more likely to show affectionate behaviour and had normal competence and caring for baby’s basic needs; however, they were more likely to get disturbed and agitated if separated from the baby. Mothers who had delusions that the baby was a devil or ill fated or someone else’s baby, were more likely to have significant abusive incidents towards the baby. Overall, the mothers who had delusions related to the infant were seen to have more significant abusive incidents and were more likely to be considered unsafe in looking after the baby alone. The study emphasises the need for systematic clinical assessment of psychopathology in mothers with postpartum psychosis.     

Maternal attachment influences mother–infant styles of regulation and play with objects at nine months

We examined the association between the quality of maternal representations of attachment evaluated by the Adult Attachment Interview (AAI) and mother styles of regulating attention and emotion during free play with objects in 41 mother dyads when infants were nine months old. The secure mother dyads showed a greater duration of engagement matches, with more positive matches, and a greater capacity to move from non-matched to matched states. Secure mother dyads demonstrated greater involvement in play with objects than insecure mother dyads. Insecure mother dyads showed a greater duration of mismatches and spent more time in negative matches. Correlations between maternal AAI scores and the variables studied also showed that the maternal Passivity and Unresolved scales were associated with less adequate dyadic attention and emotion regulation, while the maternal Coherence scale was associated with more adequate dyadic attention and emotion regulation.     

Independent influences upon mother–toddler role reversal: infant–mother attachment disorganization and role reversal in mother's childhood

In role reversal a child takes an inappropriate parental, spousal, or peer role with the caregiver. The study assessed attachment disorganization with mother in infancy in the Strange Situation (Ainsworth, Blehar, Waters, & Wall, 1978 Ainsworth, M. D.S., Blehar, M. C., Waters, E. and Wall, S. 1978. Patterns of attachment: A psychological study of the strange situation, Hillsdale, NJ: Erlbaum.  [Google Scholar]) and role reversal at 2 years old in videotaped mother–child interactions. By closely observing role reversal at this early age, results fill in the picture concerning the link between disorganized infant–mother attachment and controlling role reversal at 6 years old (Main & Cassidy, 1988 Main, M. and Cassidy, J. 1988. Categories of response to reunion with the parent at age 6: Predictable from infant attachment classifications and stable over a 1-month period. Developmental Psychology, 24: 415–426. [Crossref], [Web of Science ®] , [Google Scholar]; Main, Kaplan, & Cassidy, 1985 Main, M., Kaplan, N. and Cassidy, J. C. 1985. “Security in infancy, childhood, and adulthood: A move to the level of representation”. In Monographs of the Society for Research in Child Development Edited by: Bretherton, I. and Waters, E. 50(Serial No. 209, 1–2), 66–104[Crossref] , [Google Scholar]). As hypothesized, infant–mother disorganization significantly predicted mother–toddler role reversal. The study also deepened research that predicted role reversal from parent Adult Attachment Interview (AAI) role reversal assessed before the child was born (Macfie, McElwain, Houts, & Cox, 2005 Macfie, J., McElwain, N. L., Houts, R. M. and Cox, M. J. 2005. Intergenerational transmission of role reversal between parent and child: Dyadic and family systems internal working models. Attachment & Human Development, 7: 51–65. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). As hypothesized, mother AAI role reversal with her mother in childhood significantly predicted mother–toddler role reversal over and above infant–mother disorganization. Results are discussed within a developmental psychopathology framework including opportunities for developmentally sensitive interventions.     

Microstructure and tensile properties after thermohydrogen processing of Ti–6Al–4V

Thermohydrogen processing (THP), a technique in which hydrogen is used as a temporary alloying element, can refine the microstructure and improve the final mechanical properties of the Ti–6Al–4V alloy. THP allows microstructural modification of titanium alloys near net shape such as biomaterial components obtained by powder metallurgy and castings, since it does not require mechanical working. Two THP, called THP-A and THP-B, have been evaluated in samples of Ti–6Al–4V with a coarse and lamellar microstructure typical of castings and powder metallurgy. The THP-A is based in the eutectoid decomposition of the ${\beta }_H$ phase to $\alpha$ phase and hydride phase. The THP-B is based in the isothermal decomposition of ${\alpha }^{″}$ martensite phase, obtained by quenching of hydrogenated samples. The refinement of the microstructure due to THP has been evaluated by means of optical and electron microscopy. Tensile tests showed that while both processes were able to increase the strength of the alloy as compared with the starting material, the ductility in samples subjected to THP-B was severely reduced.     

Mothers with borderline personality disorders' experiences of mother–infant dialectical behavior therapy

Background: Borderline personality disorder (BPD) is increasingly diagnosed in perinatal and infant settings, and research suggests that as well as an escalation of BPD symptoms in this period, these symptoms may also be detrimental to infant development. Providing tailored treatments during the postnatal period may help women and prevent an intergenerational cycle of emotional and interpersonal symptoms in infants. Mother–infant dialectical behavior therapy (MI-DBT) has produced promising, yet inconsistent, improvements on quantitative scales of maternal mental health and the mother–infant relationship. The qualitative evaluation may provide complementary information. Aims: This study aimed to explore the subjective experiences of women who had completed MI-DBT. Material and Methods: Thematic analysis of semistructured interviews conducted on 13 women undertaking MI-DBT before, post, and 12 months after MI-DBT were analyzed for themes. Results: Five major themes were identified. Overall, the women expressed that their emotional literacy and regulation improved after MI-DBT, subsequently addressing key risks and challenges such as uncertainty around their child's cues, and low self-esteem, and potentially improving the women's mentalization capability. Discussion and Conclusions: This study consolidates previous research on maternal BPD, and provides qualitative evidence of the benefits of MI-DBT for mothers as both individuals and as parents with likely flow-on effects for infants. Lived experience input for future adaptations was a valuable gain.     

Maternal distress,DNA methylation,and fetal programing of stress physiology in Brazilian mother–infant pairs

Maternal prenatal psychosocial stress is associated with adverse hypothalamic–pituitary–adrenal axis (HPAA) function among infants. Although the biological mechanisms influencing this process remain unknown, altered DNA methylation is considered to be one potential mechanism. We investigated associations between maternal prenatal psychological distress, infant salivary DNA methylation, and stress physiology at 12 months. Mother's distress was measured via depression and anxiety in early and late pregnancy in a cohort of 80 pregnant adolescents. Maternal hair cortisol was collected during pregnancy. Saliva samples were collected from infants at 12 months to quantify DNA methylation of three stress-related genes (FKBP5, NR3C1, OXTR) (n = 62) and diurnal cortisol (n = 29). Multivariable linear regression was used to test for associations between prenatal psychological distress, and infant DNA methylation and cortisol. Hair cortisol concentrations in late pregnancy were negatively associated with two sites of FKBP5 (site 1: B = −22.33, p = .003; site 2: B = −15.60, p = .012). Infants of mothers with elevated anxiety symptoms in late pregnancy had lower levels of OXTR2 CpG2 methylation (B = −2.17, p = .03) and higher evening salivary cortisol (B = 0.41, p = .03). Furthermore, OXTR2 methylation was inversely associated with evening cortisol (B = −0.14, p-value ≤ .001). Our results are, to our knowledge, the first evidence that the methylation of the oxytocin receptor may contribute to the regulation of HPAA during infancy.     

Further evidence of the limited role of candidate genes in relation to infant–mother attachment outcomes

In this paper, we examine the associations between specific candidate genes (DRD2, DRD4, COMT, biallelic and tri-allelic 5HTTLPR, and OXTR) and infant attachment outcomes as main effects and in conjunction with maternal sensitivity. The sample included 200 infants (97 European American, 94 African-American, and 9 biracial) and their mothers. Maternal sensitivity and overtly negative maternal behavior were observed when infants were 6 months and 1 year old in distress-eliciting contexts, attachment was assessed via the Strange Situation at age 1, and DNA samples were collected when children were 2 years old. Consistent with recent research in large samples, there was little evidence that these genes are associated with attachment security, disorganization, or distress as main effects (in additive, dominant, and homozygous models) or in conjunction with maternal sensitivity or overtly negative behavior (primarily dominance models). Furthermore, there was little evidence that associations vary as a function of race.     

Cohort study of depressive moods in Thai women during late pregnancy and 6–8 weeks of postpartum using the Edinburgh Postnatal Depression Scale (EPDS)

Summary Objective: To identify depressive moods as measured by the Edinburgh Postnatal Depression Scale in late pregnancy and postpartum, explore associated factors and assess changes in depressive moods. Methods: A cohort study of 610 pregnant Thai women was conducted. The self-reporting EPDS was completed at 36–40 weeks and at 6–8 weeks postpartum. Result: The prevalence of depressive moods (scores of 10 or more on the EPDS) was 20.5% during pregnancy and 16.8% at postpartum. Factors related to depressive moods in late pregnancy included marital status, evidence of irritable moods before menstruation, and attitudes towards this pregnancy. Unmarried women, women having irritable moods before menstruation or women having negative attitudes towards this pregnancy had double risk. Related factors during the postpartum period included religion, evidence of irritable moods before menstruation, perception of pregnancy complications and attitudes towards this pregnancy (p < 0.01). Women who perceived of having complications during this pregnancy, those who had irritable moods before menstruation or had negative attitudes towards this pregnancy had also double risk. The depressive moods were significantly reduced postnatally. Conclusion: One-fifth of pregnant and postpartum women experienced depressive moods but the severity declined at postpartum.     

Supporting the adolescent mother–infant relationship: preliminary trial of a brief perinatal attachment intervention

The purpose of this study is to test a brief, attachment intervention added to routine maternity care that aims to improve the adolescent mother–infant relationship during transition to motherhood. A pre-test, post-test, peer–control–group trial was set in a large tertiary maternity hospital in Melbourne, Australia. Participants were multi-cultural, pregnant adolescents (n?=?97). The two-session ‘AMPLE’ intervention was provided in late pregnancy and neonatally. The main outcome measure was mother–infant interaction quality at age 4 months, blind-coded using the Emotional Availability Scales (EAS) (fourth edition). Study acceptability was high: participation rate 82.9 % and completion rate 75.3 %. Thirty-five participants received the intervention plus usual care (intervention group) and 38 received usual care (control group). There were no pre-test between-group differences across demographic, psychosocial or obstetric domains. At post-test, mother–infant interaction was significantly better in the intervention group. MANOVA analyses showed an overall intervention effect on emotional availability in 20 min of free play (n?=?73), F (6,65)?=?5.05, p?<?.01, partial η ²?=?.32, and in 25 min of play plus brief separation–reunion (n?=?55), F (6,48)?=?2.72, p?=?.02, partial η ²?=?.25. T tests showed significant between-group differences in specific EAS subscales. All effect sizes were medium–large. This promising intervention appears to exert a clinically meaningful effect on the adolescent mother–infant relationship. Further research is warranted to replicate the findings and confirm causality. The study suggests a brief attachment focus, incorporated into routine maternity care, could influence the developmental trajectory of infants of young mothers from birth.     

Subclinical depressive symptoms during pregnancy and birth outcome—a pilot study in a healthy German sample

There is a high prevalence of depression in Germany and all over the world. Maternal depressive symptoms during pregnancy have been shown in some studies to be associated with an increased risk of preterm birth and low birth weight. The influence of maternal depressive symptoms during pregnancy on preterm delivery and fetal birth weight was investigated in a prospective single-centre study. A sample of 273 healthy pregnant women was assessed for symptoms of antepartum depression. Symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS) and the Patient Health Questionnaire (PHQ). Symptoms of anxiety were assessed using the State/Trait Anxiety Inventory. Patients who scored above the cutoff were contacted by phone for a Structured Clinical Diagnostic interview. Neonatal measurements were obtained from the birth registry of the Department of Obstetrics. Baseline data were assessed with a self-styled data sheet. Prevalence of elevated depressive symptoms was 13.2 % when measured with the EPDS and 8.4 % with the PHQ. According to DSM-IV criteria, only four (EPDS) respective two (PHQ-D) of these patients could be diagnosed with a depressive disorder and ten (EPDS) respective seven (PHQ) with an anxiety disorder. There was no significant influence on preterm birth or birth weight. Maternal depressive symptoms are self-reported. Elevated subclinical symptoms of depression and anxiety during pregnancy are common. However, this study showed no evidence that these symptoms are associated with adverse pregnancy outcome.