Mother-infant Behavior Research Articles

Breastfeeding at Any Cost? Adverse Effects of Breastfeeding Pain on Mother-Infant Behavior.

Breast milk is considered the ideal infant nutrition, and medical organizations encourage breastfeeding worldwide. Moreover, breastfeeding is often perceived as a natural and spontaneous socio-biological process and one of the fundamental roles of new mothers. While breastfeeding is beneficial, little scientific consideration has been given to its potential psychological challenges. Here, we investigate the phenomenon of breastfeeding pain in mothers and its association with maternal and infant behavioral regulation. During the postpartum weeks, the mother-infant dyad can be considered one allostatic unit directed at infant regulation and development. We hypothesize that pain comprises an allostatic challenge for mothers and will thus impair the capacity for dyadic regulation. To test this, we recruited 71 mothers with varying levels of breastfeeding pain and videotaped them with their infants (2-35 weeks old) during spontaneous face-to-face interactions. We quantified the individual differences in dyadic regulation by behaviorally coding the second-by-second affective expressions for each mother and infant throughout their interactions. We tested the extent to which breastfeeding pain alters affect regulation during mother-infant interactions. We discovered that mothers with severe breastfeeding pain express less affective expressions and less infant-directed gaze during interactive moments of engagement and play than mothers with no or moderate pain. Moreover, infants of mothers experiencing pain during breastfeeding express less affective expressions and more mother-directed gaze while interacting with their mothers than infants of mothers who are not in pain. This demonstrates that the allostatic challenge of maternal pain interferes with the behavioral regulation of both mothers and infants. Since the mother-infant dyad is a codependent allostatic unit, the allostatic challenges of one partner can impact the dyad and thus potentially impact child development, bonding, and mother and infant well-being. The challenges of breastfeeding should be considered in addition to the nutritional advances.

Evidence for cultural differences in affect during mother–infant interactions

Maternal care is considered a universal and even cross-species set of typical behaviors, which are necessary to determine the social development of children. In humans, most research on mother–infant bonding is based on Western cultures and conducted in European and American countries. Thus, it is still unknown which aspects of mother–infant behaviors are universal and which vary with culture. Here we test whether typical mother–infant behaviors of affect-communication and affect-regulation are equally represented during spontaneous interaction in Palestinian-Arab and Jewish cultures. 30 Palestinian-Arab and 43 Jewish mother–infant dyads were recruited and videotaped. Using AffectRegulation Coding System (ARCS), we behaviorally analyzed the second-by-second display of valence and arousal in each participant and calculated the dynamic patterns of affect co-regulation. The results show that Palestinian-Arab infants express more positive valence than Jewish infants and that Palestinian-Arab mothers express higher arousal compared to Jewish mothers. Moreover, we found culturally-distinct strategies to regulate the infant: increased arousal in Palestinian-Arab dyads and increased mutual affective match in Jewish dyads. Such cross-cultural differences in affect indicate that basic features of emotion that are often considered universal are differentially represented in different cultures. Affect communication and regulation patterns can be transmitted across generations in early-life socialization with caregivers.

Efeito da Prematuridade e Temperamento na Interação Mãe-Bebê

Abstract We evaluated the effect of prematurity and the infant’s temperament on the mother-infant behaviors in the Face-to-Face Still-Face Paradigm (FFSF). The study included 75 mothers and their infants (37 preterm and 38 term) between three and four months of age (corrected age for preterm infants). The mothers responded to a perception scale of the infants’ temperament and the dyads were observed in a structured condition (FFSF). The FFSF Paradigm, divided into three episodes, made it possible to analyze the behaviors of: Positive Social Orientation, Negative Social Orientation and Self-comfort. The averages recorded for these categories were analyzed in a Multivariate ANOVA (factors: prematurity and temperament). Temperament had more effect on maternal and infant behaviors, suggesting that this factor may influence mother-infant interaction. The results can guide possible interventions with families.

FACTORS AFFECTING ANXIETY OF BREAST MILK IN BREASTFEEDING MOTHERS : SCOPING REVIEW

Anxiety before and after childbirth can interfere with maternal function and mother-infant behavior including breastfeeding. Exclusive breastfeeding is breastfeeding alone without any additional food for 6 full months. Not all mothers give exclusive breastfeeding to their babies. This is influenced by various anxiety factors such as not initiating breastfeeding, breastfeeding duration. In this study using a scoping review methodology. This study combines knowledge and information related to current assumptions regarding the factors that influence exclusive breastfeeding. This study emphasizes breastfeeding anxiety factors such as breastfeeding initiation, breastfeeding duration and identifies 8 articles from a total of 8 articles, which were reviewed and summarized in a narrative manner. The findings of this study indicate that anxiety is the main factor for optimal breastfeeding. This research is expected to improve outcomes, and can be used as input for policy makers, health workers and service users.

Variation in the Mu-Opioid Receptor (OPRM1) and Offspring Sex Are Associated With Maternal Behavior in Rhesus Macaques (Macaca mulatta).

A μ-opioid receptor (OPRM1) single-nucleotide-polymorphism, found in both humans and rhesus macaques mediates the mother-infant attachment bond. Because mothers treat their sons and daughters differently, it is somewhat surprising that the role of infant sex has not been assessed in the context of a maternal-OPRM1-genotype-by-infant-sex interaction. The present study investigates the effect of maternal-OPRM1-genotype and infant sex on mother-infant behaviors. Over the first 6 months of offspring life, mother-infant behavioral data assessing attachment quality was collected twice weekly from a large number of rhesus monkey mother-infant pairs (N = 161 dyads; n = 64 female infants, n = 97 male infants). Mothers were genotyped for OPRM1 variation. Factor analysis of the observed behaviors showed two factors: Attachment (maternal-infant cradling, rejections, and infant approaches and leaves), and Maternal Restraints (mother restrains infant, preventing exploration). Further analyses showed a two-way, maternal-genotype-by-infant-sex interaction for both factors. For Attachment, mothers with the CC genotype cradled and restrained (Maternal Restraints) their female infants more and rejected them less, when compared to female infants of CG mothers. Perhaps as a consequence, female infants of CC genotype mothers approached and left their mothers less often, when compared to female infants of CG mothers, likely an indication that female infants from mothers with CG genotype play a greater role in maintaining the mother-infant bond than do female infants from CC genotype mothers. This finding may also indicate a more secure attachment in infants from CC genotype mothers. Unlike female infants, on average, the mother-infant relationship of dyads with a male infant was largely undifferentiated by maternal genotype. These findings suggest that, in contrast to female infants from CG mothers, CC mothers and their female infants appear to have a closer mother-infant relationship which may portend close life-long bonds, as mothers and female offspring remain together throughout life. Male offspring appear to have a more aloof mother-infant bond regardless of OPRM1-genotype. The results of this study indicate that maternal-OPRM1 variation mediates mother-infant attachment behaviors for female infants and has less effect for male infants. This suggests that offspring sex should be included in studies investigating the effect of maternal-OPRM1 genotype on the mother-infant attachment relationship.

Breastfeeding Training through Role-Play and Effects on Mother-infant Attachment Behaviours: A Randomised Controlled Trial

Mother-infant attachment is an intimate, lasting and satisfying relationship that leads to better cognitive, emotional and social growth of the infant. The aim of this study was to determine the effects of breastfeeding training by role-play on mother-infant attachment behaviours. This research was a randomised clinical trial (parallel design). Inclusion criteria were: no history of mental disorders; ability to read and write the Persian language to complete the questionnaire; no history of drug and tobacco intake in primigravida women. The sample comprised 100 pregnant women (in 2 groups), selected through simple random sampling at healthcare centres. The researcher reviewed prenatal care registries of selected healthcare centres and extracted the names of pregnant women in their early third trimester. The data were imported into randomisation software. The control group received routine breastfeeding training, while the intervention group received routine training together with training through role-play. The data collection tool was the Maternal Behaviour Inventory Questionnaire. Consequently 75 samples were analysed in SPSS16. Independent t-tests and chi-square tests were used to examine the difference between the two groups. Results showed that the mean score of mother-infant attachment one week after delivery was significantly higher in the intervention group in comparison to that in the control group (p<0.001). No significant difference was observed between the two groups in maternal age, age of marriage, neonatal gender, maternal employment and education, number of parity, and number of abortions (P>0.05). Since breastfeeding training through role-play could affect mother-infant attachment, it is suggested that this type of training should be provided for pregnant women to promote mother-infant attachment and exclusive breastfeeding.

Fostering mother-very preterm infant communication during skin-to-skin contact through a modified positioning

BackgroundSkin-to-skin contact (SSC) has been widely studied in NICU and several meta-analyses have looked at its benefits both for the baby and the parent. Very few studies however have investigated benefit for communication. AimsInvestigate the immediate benefits of Supported Diagonal Flexion (SDF) positioning during SSC on the quality of mother - very-preterm infant communication and to gain insight into how mothers' and very-preterm infants' communicative behaviours are coordinated in time just a few days after birth. Subjects and study designMonocentric prospective matched-pair case-control study. Thirty-four mothers and their very preterm infants (27 to 31 + 6 weeks GA; mean age at birth 30: weeks GA) were assigned to one of the two SSC positioning, either the Vertical Control (n = 17) or the SDF Intervention positioning (n = 17). Mother and infant were filmed during the first 5 min of SSC, 15 days after the very first SSC (i.e. 18 days after very premature birth, i.e. on average 32.4 weeks GA). Outcome measuresInfants' state of consciousness according to the Assessment of Preterm Infants' Behavior scale. Onset and duration of infants' and mothers' smiles, gazes and vocalizations, and their temporal proximity inside a 1-sec time-window. ResultsIn the SDF Intervention Group, very preterm infants vocalized three times more and mothers vocalized, gazed at their baby's face, and smiled more than in the Vertical Control Group. Moreover, in a one-second time-frame, temporal proximity of mother-infant behaviours was greater in the SDF Intervention Group. ConclusionsOur study shows that SDF positioning creates more opportunities for mother-infant communication during SSC. SDF positioning fosters a greater multimodal temporal proximity thus supporting a more qualitative mother-infant communication.

Impact of Maternal Anxiety on Breastfeeding Outcomes: A Systematic Review

Prenatal and postpartum anxiety may impair maternal functioning and disrupt mother-infant behaviors including breastfeeding. The objective of this narrative review is to examine the association between maternal anxiety from pregnancy to 12 mo postpartum and breastfeeding initiation, duration, and exclusivity. Using a combination of Medical Subject Headings terms and text words, relevant studies were identified through PubMed and PsycINFO. Studies that were conducted in high-income countries, assessed anxiety during gestation and/or postpartum through a standardized measure, and evaluated the impact of anxiety on any of the primary outcomes were included. Sixteen studies met the eligibility criteria although they varied greatly in methodological rigor. A negative association between postpartum anxiety and breastfeeding initiation, duration, and exclusivity was suggested. No associations were found between prenatal anxiety and breastfeeding initiation or exclusivity. Evidence is mixed regarding the association between prenatal anxiety and breastfeeding duration. All studies included in the review were of low or very low quality. Although there was consistency in the association between maternal anxiety and breastfeeding outcomes in the included studies, future studies with greater methodological rigor are needed to determine the extent of the relation between prenatal and/or postpartum anxiety and breastfeeding outcomes.

Nurturescience versus neuroscience: A case for rethinking perinatal mother-infant behaviors and relationship.

Behavioral and emotional outcomes for babies who experienced maternal separation due to prematurity or birth defects have not improved significantly for the last 20 years. Current theories and treatment paradigms based on neuroscience have not generated explanatory mechanisms that work, or provided testable hypotheses. This article proposes a new field of scientific investigation, "nurturescience" within which new hypotheses can be tested with novel instruments. Key distinctions between neuroscience and nurturescience are described. Our definition of nurturescience is based on the basic needs of all newborns and of the needs of mothers and their families. This understanding is drawn from biology, anthropology, sociology, physiological, and clinical research. Mechanisms are described from studies on microbiota, epigenetics, allostasis, brain imaging, and developmental origins of health and adult disease. The converging message from these and other fields is that the mother-infant dyad should not be separated. Ongoing emotional connection is the cornerstone of development, leading to life-long resilience. This has implications for making the correct diagnosis (emotional disconnection vs. attachment disorder), providing the appropriate care (infant and family centered developmental care) in the biologically expected place (skin-to-skin contact), and potential for rehabilitation (calming cycle theory). Nurturescience has particular relevance to the care of "small and sick" infants, with profound potential for decreasing the "likelihood of developing developmental problems."

Correction: Asymmetries in mother-infant behaviour in Barbary macaques (Macaca sylvanus).

[This corrects the article DOI: 10.7717/peerj.4736.].

A RELAÇÃO MÃE-BEBÊ NO CONTEXTO DA DEPRESSÃO PÓS-PARTO: ESTUDO QUALITATIVO

Current study analyzes how depressive symptomology in females during the post-partum period affects the mother-infant behavior. Qualitative research comprised interviews with six mothers, aged between 20 and 38 years, attended to at a Basic Health Unit, and who exhibited symptoms of depression during the after-birth period. The half-structured interview was employed for data collection. Results from content analysis revealed that mother´s depression symptoms affected the mother-child relationship within three categories: affective ambivalence during dyade, mother´s difficulties in breast feeding and instability in the infant´s sleep. During the pregnancy-puerperal period, the mother has to be psychologically supported to acknowledge, prevent and interfere on factors that affect her mental health and promote the healthful development in mother-child relationship.

Impact of prenatal stress on mother-infant dyadic behavior during the still-face paradigm

BackgroundMother-infant interaction provides important training for the infant’s ability to cope with stress and the development of resilience. Prenatal stress (PS) and its impact on the offspring’s development have long been a focus of stress research, with studies highlighting both harmful and beneficial effects. The aim of the current study was to examine the possible influence of both psychological stress and hypothalamic-pituitary-adrenal (HPA) axis activity during pregnancy with mother-child dyadic behavior following stress exposure.MethodsThe behavior of 164 mother-infant dyads during the still-face situation was filmed at six months postpartum and coded into three dyadic patterns: 1) both positive, 2) infant protesting-mother positive, and 3) infant protesting-mother negative. PS exposure was assessed prenatally according to psychological measures (i.e., psychopathological, perceived and psychosocial PS; n = 164) and HPA axis activity measures (maternal salivary cortisol, i.e., cortisol decline and area under the curve with respect to ground (AUCg); n = 134).ResultsMother-infant dyads in both the high- and low-stress groups showed decreasing positive and increasing negative dyadic behavior in the reunion episode, which is associated with the well-known “still-face” and “carry-over” effect. Furthermore, mother-infant dyads with higher psychosocial PS exhibited significantly more positive dyadic behavior than the low psychosocial PS group in the first play episode, but not in the reunion episode. Similarly, mother-infant dyads with high HPA axis activity (i.e. high AUCg) but steeper diurnal cortisol decline (i.e. cortisol decline) displayed significantly less negative behavior in the reunion episode than dyads with low HPA axis activity. No significant results were found for psychopathological stress and perceived stress.ConclusionsThe results suggest a beneficial effect of higher psychosocial PS and higher prenatal maternal HPA axis activity in late gestation, which is in line with “stress inoculation” theories.

Impact of prenatal stress on the dyadic behavior of mothers and their 6-month-old infants during a play situation: role of different dimensions of stress.

Prenatal stress (PS) is an established risk factor in the etiology of mental disorders. Although mother-child interaction is the infant's first important training in dealing with stress, little is yet known about the impact of PS on mother-infant dyadic behavior. The current study aimed to elucidate the prospective influence of psychological and physiological stresses during pregnancy on mother-infant dyadic behavior. Mother-infant interactions were videotaped at 6-month postpartum and coded into three dyadic patterns: (1) both positive; (2) infant protesting-mother positive; and (3) infant protesting-mother negative, using the infant and caregiver engagement phases. Exposure to PS was assessed during pregnancy using psychological (i.e., psychopathological, perceived, and psychosocial PS; n=164) and physiological stress measures (i.e., maternal cortisol; n=134). Group comparisons showed that psychosocial PS was predictive of mother-infant behavior at 6-month postpartum, indicating that dyads of prenatally high-stressed mothers exhibited significantly more positive interaction patterns (i.e., infant positive-mother positive) as compared to the prenatally low-stressed group. Physiological PS was unrelated to mother-infant behavior. These results suggest that mild psychosocial PS may be advantageous for positive mother-infant dyadic behavior, which is in accordance with the stress-inoculation model that assumes a beneficial effect of PS.

The Effect of Family-centered Care Program on Maternal Attachment in Mothers of Premature Infants

BACKGROUND AND OBJECTIVE: The birth of a premature infant is associated with long - term hospitalization and separation from family. Hospitalization of the infant affects the attachment between the infant and mother and affects the quality of care given to the infant by mother and increases the risk of delayed behavioral problems. Therefore, the present study aims to analyze the effect of family-centered care program on maternal attachment in mothers of premature infants. METHODS: In this clinical trial, 60 mothers of premature infants with gestational age of 30 to 36 weeks, hospitalized in neonatal intensive care unit of Motahari Hospital were selected using convenient non-probability sampling and were randomly divided into two groups of control and intervention (30 mothers in each group). The family-centered care program was performed on intervention group in three steps: In the beginning of infant care, before the fourth day of hospitalization and before discharge, while the control group was only under the usual care. The level of maternal attachment was measured using Avant's mother-infant attachment behavior questionnaire and each dimension of attachment behavior was scored from 0 to maximum based on care (45), proximity (45) and emotional (37) behavior (IRCT: 2017021914454N3) FINDINGS: The total score of maternal attachment increased from 34.3±5.1 to 61.6±4.5 in intervention group and increased from 33.1±4.2 to 37.8±3.7 in control group. There is a significant difference between the two groups in terms of total score of attachment between mother and premature infant (p<0.001). CONCLUSION: Results of the study demonstrated that implementation of family-centered care program increases the attachment between mother and infant more than common infant-care methods. © 2017, Babol University of Medical Sciences. All rights reserved.

Household environment and behavioral determinants of respiratory tract infection in infants and young children in northern Bangladesh.

Respiratory tract infections (RTI) are one of the leading causes of under-five mortality in Bangladesh. Solid biomass fuels are the main source of domestic fuel used for cooking across Bangladesh, leading to smoke and pollution exposure in the home. This article aims to identify risk factors for RTI among children aged under five years in Bangladesh with a particular focus on the household environment, fuel use, and cooking practices. A cross-sectional household-health survey was carried out in 321 households in northern Bangladesh. The survey included care-giver interviews on cooking practices, child health, and household behaviors during cooking. Health status of the youngest child (under five years) from each household was recorded through maternal interviews, medical diagnosis, and assessment of biomarkers (C-reactive protein (CRP), hemoglobin) from finger-prick blood samples. Anthropometric status (weight, height) was recorded. Children who spent ≥30 minutes/day within 5 feet of the stove during cooking had a significantly increased risk of moderate/severe RTI compared with children spending <30 minutes/day close to the stove (OR = 2.15, 95%CI: 1.20-3.86, P = 0.01), independent of socio-economic status (SES), biomass fuel type (wood, dung, plant-derived, compressed rice husks), child age, anthropometric status, CRP and hemoglobin. In environments with a heavy reliance on solid biomass fuels, the amount of time a child spends near the stove during cooking may be an important risk for RTI. These novel findings from Bangladesh warrant further investigation of mother-infant behaviors during cooking in relation to child health, to ascertain whether the association is likely to be causal.

Boys will be boys: sex differences in wild infant chimpanzee social interactions

Sex differences in the behaviour of human children are a hotly debated and often controversial topic. However, several recent studies have documented a biological basis to key aspects of child social behaviour. To further explore the evolutionary basis of such differences, we investigated sex differences in sociability in wild chimpanzee, Pan troglodytes schweinfurthii, infants at Gombe National Park, Tanzania. We used a long-term data set on mother-infant behaviour to analyse the diversity of infant chimpanzee social partners from age 30 to 36 months. Male infants (N = 12) interacted with significantly more individuals than female infants did (N = 8), even when maternal sociability was controlled for. Furthermore, male infants interacted with significantly more adult males than female infants did. Our data indicate that the well-documented sex differences in adult chimpanzee social tendencies begin to appear quite early in development. Furthermore, these data suggest that the behavioural sex differences of human children are fundamentally rooted in our biological and evolutionary heritage.

Maternal Representations and Mother-Infant Relational Behavior Following Parent-Infant Psychotherapy

To examine how relational behavior and maternal representations are manifested before and after parent-infant psychotherapy, mothers’ and infants’ behaviors and maternal narratives were assessed in 45 clinic-referred dyads who participated in psychodynamically informed parent-infant psychotherapy. Pretreatment and posttreatment assessments included observations of mothers’ and infants’ behaviors (CIB; Feldman, 1998) and assessment of maternal representations (PDI; Aber, Slade, Berger, Bresgi, & Kaplan, 1985). Parent-infant psychotherapy consisted of weekly child-mother, child-father, and two parents’ sessions. Following psychotherapy, maternal sensitivity and child engagement showed a significant increase. An increase was also evidenced in the richness of maternal narratives regarding the mother-infant relations. During the pretreatment assessment, maternal intrusiveness was associated with restricted narratives, lack of joyful descriptions, and reduced coherence and child engagement was associated with maternal narratives characterized by incoherence and reduced joy. Maternal reports of high psychological distress were associated with higher maternal intrusiveness and lower maternal sensitivity following psychotherapy. Discussion focuses on the unique opportunities for infants in parent-infant psychotherapy as well as the need for further understanding of the processes underpinning change following this treatment modality.

Evaluation of reproduction and raising offspring in a nursery-reared SPF baboon (Papio hamadryas anubis) colony.

Baboons (Papio hamadryas anubis) of a conventional breeding colony were nursery-reared to create a specific pathogen-free (SPF) baboon-breeding program. Because the founding generations were nursery-reared until 2 years of age, it was suspected that the SPF baboons would exhibit increased reproductive challenges as adults. Mothering behavior was of interest, because SPF females were not exposed to parental role models during the nursery-rearing process. We compared reproductive data from the SPF baboon breeding program during its first 10 years with data from age-matched baboons during the same period from an established, genetically-similar conventional breeding colony. We also evaluated records documenting mother-infant behaviors within the SPF colony. The average age of menarche in SPF females was 3.3 years. The overall live birth rate of both SPF and conventional females was approximately 90%, with no difference in pregnancy outcome between the two colonies. The average age at first conception for SPF females was earlier (4.2 years) than that of the conventional females (4.7 years). In both colonies, primiparous females were more likely to abort than multiparous females. Similarly, primiparous females were more likely to lose their infants to death or human intervention. A mothering score system was developed in the SPF colony to facilitate intervention of poor mother-infant relationships. Records revealed 70% of SPF mothers were able to raise one or more of their infants successfully to at least 180 days of age, which did not differ from conventional mothers. SPF females returned to post-partum amenorrhea 27 days sooner on average than the conventional females, independent of dam age. The nursery-rearing process used for recruitment into the SPF colony therefore did not have an adverse effect on reproduction or rearing offspring.

Stability of parental care across siblings from undisturbed and challenged pregnancies: Intrinsic maternal dispositions of female rhesus monkeys.

The concept of fetal programming is based on the idea that the developmental trajectory of infants is adjusted in response to in utero conditions. In species with extended parental care, these prenatally derived tendencies are further substantiated by behavioral attributes of the mother during the postnatal period. We investigated the stability of maternal behavioral interactions with infant monkeys and carefully varied prenatal conditions across siblings reared by the same mother. We hypothesized that effects of prenatal disturbance and the infant's susceptibility would be differentially affected by maternal attributes. Using hierarchical linear modeling, we analyzed observational data on 121 rhesus macaques reared by a total of 35 multiparous mothers. A portion of the variance in 5 dyadic behaviors was statistically driven by the infant (or was unique to a particular mother-infant pair), but stable maternal propensities and a consistent style of care across siblings also substantially influenced behavioral interactions. Moreover, the magnitude and direction of the prenatal effects were contingent on a female's intrinsic dispositions. When mothers typically exhibited high levels of a corresponding behavior, responsiveness to infants was enhanced as a consequence of prenatal disturbance. The opposite was true for less expressive females. Challenges to the well-being of pregnancy thus served to accentuate maternal predispositions and served to magnify the range of variation in mother-infant behavior across the whole population.

Relation of mother‐infant interaction to infant weight and length in rural Southern Ethiopia

Study objective was to identify mother‐infant (n= 60) behaviors linked to 6‐mo infant weight and length in breastfed infants in 2010 in Sidama, Ethiopia, a region stricken by famine in 2009. Preliminary data on videotaped behaviors are reported for 26 mother‐infant pairs. Interrater reliabilities on infant behaviors ranged from r =.65 to .89; on maternal behaviors they ranged from r =.53 to.81. Behaviors were validated with mothers’ Edinburgh Postpartum Depression Scale (EPDS, translated into Amharic) and social support (SS) scores. Correlations were: infant vocalizations with EPDS and SS, r = −.34 and r = .46, ps &lt; .05; infant distress with EPDS, r = .50, p &lt; .01; infant activity with SS, r = .47, p &lt; .01; mother response to infant vocalization with EPDS and SS, r = −.38 and r = .45, ps &lt; .05. Infants’ vocalizations and mothers’ responses were linked to infant weight‐for‐length: r = .27, p &lt; .10 and r = .35, p &lt; .05. Infant distress was linked to infant weight‐and length‐for‐age: r = .45 and r = .50, ps &lt; .01. Findings on distress and growth are consistent with research on alertness and growth. Vocalization findings are congruent with functional isolation hypothesis. Funding: NICHD R01 053053.