Sleep position, autonomic function, and arousal

AIMS: To investigate and compare heart rate variability (HRV) and responses of heart rate and arousal to head-up tilting in infants sleeping prone and supine. METHODS: Thirty seven healthy infants aged 2-4 months were studied. HRV was measured for 500 beats while they were in a horizontal position. Subjects were then tilted 60 degrees head-up, and heart rate recorded over 1 minute and arousal responses observed. Data were collected during both quiet and active sleep for both prone and supine sleep positions. RESULTS: HRV, as assessed by the point dispersion of Poincaré plots, was significantly reduced in the prone position for both sleep states. Sleep position did not influence the changes in heart rate seen during a head-up tilt. Full awakening to the tilt was common in active sleep but significantly less so in the prone position (15% of prone tests vs 54% supine). Full awakening to the tilt rarely occurred during quiet sleep in either sleep position. CONCLUSION: This study provides some evidence that blunted arousal responses and/or altered autonomic function are a feature of the prone sleeping position. Decreased HRV may be a sign of autonomic impairment. It is seen in many disease states and in infants who later die of sudden infant death syndrome (SIDS).     

Age-mate or twin sibling: Effects on interactions between monkey mothers and infants.

Examined the effects of the twin sibling relationship upon interactions between mother and infant. 12 rhesus monkey infants were reared with a mother and nonsibling peers; 8 had an age-mate or twin sibling, while 4 control infants did not. The sibling pairs were formed by fostering newborns 2 to a mother; the control infants were fostered 1 to a mother. Findings indicate that the twin infants did not engage in as much interaction with their mothers throughout a 7-mo period of observation on a wide range of indexes, including such basic behaviors as a contact with the mother's ventrum and nipples. The mothers rearing twins spent less time cradling their infants and less frequently rejected them. There were a few additional differences, notably in the area of restrictive behavior, but it is concluded that the differences in maternal behavior were principally a reaction to the differences in infant behavior. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cultural variation in infants' sleeping arrangements: Questions of independence.

Examines the decisions of middle-class US and Highland Mayan parents regarding sleeping arrangements during their child's 1st 2 yrs and their explanations for their differing practices. All 14 Mayan children slept in their mothers' beds into toddlerhood. None of the 18 US infants slept in bed with their mothers on a regular basis as newborns, although 15 slept near their mothers until age 3–6 mo, when most were moved to a separate room. The Mayan parents explained their practices in terms of the value of closeness with infants; US parents explained their practices in terms of the value of independence for infants. US families, but not Mayan families, used bedtime routines and objects to facilitate the transition to sleep. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Length of maternity leave and quality of mother-infant interactions

The aim of this study was to assess the association between the length of maternity leave and the quality of mother-infant interactions; 198 employed mothers of 4-month-old infants were interviewed and videotaped in their homes during a feeding time. Hierarchical multiple regression analyses indicated a direct association between shorter length of leave and more negative affect and behavior in maternal interactions with their infants. Infant and mother stressor/protective variables added significantly in predicting the quality of the mother-infant relationship. There were also significant interaction effects between the length of leave and these variables. Mothers who either reported more depressive symptoms or who perceived their infant as having a more difficult temperament and who had shorter leaves, compared with mothers who had longer leaves, were observed to express less positive affect, sensitivity, and responsiveness in interactions with their infants. The public policy implications of the relation between length of maternity leave, maternal and infant individual differences, and the quality of mother-infant interactions are discussed.     

Preliminary report on adult male isolation-reared rhesus monkeys caged with infants.

Compared the social interactions between an adult male isolation-reared rhesus monkey and an infant, housed together for 7 mo, with those of mother-infant pairs and control male-infant pairs reared under similar conditions in previous experiments. To protect the infant, pairing was gradual, the mother remaining for 1 mo. Physical contact, established 1st during sleep, was an outstanding feature of the relationship throughout. Aggression, play, and grooming were highly interrelated. the infant's attachment was stronger than the male's, was similar to that of the mother-reared infants, and was much stronger than that of the control male-reared infants. The isolate adult's lack of hyperaggressiveness, response to social cues, frequency of play, grooming, and physical contact, suggest that current ideas about the social capabilities of isolation-reared monkeys may need to be reconsidered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Natural forms of shed tumor gangliosides

Data on activity states were collected from 29 group-housed capuchin monkey (Cebus apella) infants for 3 h each week from birth to 11 weeks of age. The amounts of time spent in sleeping/drowsy, alert-quiet, and alert-active states were measured in these subjects. Videotaped observations of these infants were recorded 3 times/week in the home cage over the first year of life and were scored for a number of social and exploratory behaviors. The extent to which early infant activity state scores predicted later behavior in the home cage was examined. Infant state measures correlated significantly with home cage behavior during months 2-6 in that infants that had been more active in early infancy spent more time alone, with other animals, and in exploration and play and less time with mothers than did quieter infants. Early state measures were less successful in predicting home cage scores beyond 8 months of age, whereas differences in behavior attributable to housing variables became more salient in the latter part of the first year. There was also a negative correlation between mother and infant activity in months 2 and 3, in that more sedentary mothers tended to have more active infants.     

Contextual basis of maternal perceptions of infant temperament.

To elucidate the differential saliency of infant emotions to mothers across interactive contexts, the authors examined the moderating role of observed infant affect during interactions with mother in the relation between maternal and laboratory-based ratings of infant temperament. Fifty-nine developmentally healthy 9-month-old infants were judged for degree of infant positive, infant negative, and mother-infant mutually positive affect during the course of object-focused and routine home-based activities with mother. Mothers completed the Infant Behavior Questionnaire (M. K. Rothbart, 1981), and infants underwent the Laboratory Temperament Assessment Battery (H. H. Goldsmith & M. K. Rothbart, 1999). Results revealed that maternal and observer ratings of infant negativity converged when infants manifested high degrees of negative affect during routine home-based activities. Maternal and observer ratings of infant positivity converged when infants experienced low mutually positive affect during play. These findings support the hypothesis that maternal perceptions are based on mothers' experiences with their infants but that the salience of infant temperamental characteristics to mothers varies across emotion and interactive context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationships between neonatal characteristics and mother-infant interaction.

Studied 51 mothers and their newborn infants to evaluate the relationship between neonatal style and the early mother-infant relationship. The procedure included an infant assessment with the Brazelton Neonatal Behavioral Assessment Scale, a mother-infant interaction observation during feeding, and an interview concerning maternal attitudes and perceptions. Findings suggest that there are consistencies in infant state and behavioral measures across situations: e.g., the infant who was alert and responded to auditory cues during the Brazelton assessment looked at the mother a great deal during the feeding observation. Data also suggested consistent and interactive relationships between patterns of maternal stimulation and infant behavior in corresponding areas: e.g., the attentive sensitive mother tended to have a responsive baby and vice versa. Findings provide additional information about the early development of the complex relationship between children and parents. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serum sertraline and N-desmethylsertraline levels in breast-feeding mother-infant pairs

OBJECTIVE: The authors' goal was to study the serum sertraline levels of breast-feeding mothers and their infants. METHOD: They obtained serum levels of sertraline and N-desmethylsertraline in nine mother-infant pairs. RESULTS: Sertraline levels were very low (less than 2 ng/ml) in seven of the nine infants and low (3 ng/ml) in one. N-Desmethylsertraline levels were also low (6 ng/ml or less) in seven of the nine infants. One infant had a high level of N-desmethylsertraline, and one infant had unusual serum sertraline and N-desmethylsertraline values (half of its mother's levels). All infants were thriving. CONCLUSIONS: Most breast-feeding infants whose mothers were taking sertraline had very low serum levels of both sertraline and N-desmethylsertraline, consistent with published reports. The authors discuss in detail the one infant with unusually high levels.     

Mothers' perceptions of the care-by-parent program prior to hospital discharge of their preterm infants

PURPOSE: This research was conducted to gain an understanding of the care-by-parent experience for mothers of preterm infants. DESIGN: Phenomenologic methodology was used to explore the experiences of six mothers. Each participant slept overnight with her infant in a private hospital room. The mother assumed responsibility for her infant's care, knowing that nursing staff assistance was available if needed. Interviews were conducted on the following day and again after the infant had been home at least four days. SAMPLE: The participants were six mothers of preterm infants. MAIN OUTCOME VARIABLE: Mothers' experiences as they assumed responsibility in caring for their preterm infants away from the intensive care nursery. RESULTS: Findings revealed that the care-by-parent experience gives the mother an opportunity to assume full responsibility for her preterm infant's care, tests the reality of caregiving, helps her learn about caregiving activities and her infant's patterns of behavior, and confirms her readiness for independent parenting and the infant's readiness for discharge home. These findings confirm the benefits of rooming-in prior to discharge of preterm infants and provide guidelines for discharge planning.     

The effects of frequently rotating shiftwork on sleep and the family life of hospital nurses

The effects of three frequently rotating shifts in an irregular sequence on the daily activities of 239 Japanese female hospital nurses were studied by the time-budget method. The nurses recorded their daily activities for several consecutive days. The questionnaire was returned by 80.8% of the participants, and recordings of 1016 days were analysed. A two-way analysis of variance clarified that the shift combination influenced the daily activities. The most distinct result was that nurses spent significantly more time on free-time activities on the day when they worked the night shift followed by the evening shift than they did on the day when they worked any other shift combination. Nurses offset sleep deprivation either by sleeping during the day before and after working the night shift (82-100%) or by sleeping 2 to 4 h later in the morning after working the evening shift and on days off. There was a strong positive correlation between total sleep time (including day sleep) and the length of the interval between two consecutive shifts (r = 0.95, p < 0.001). This result suggests that more than 16 h between work shifts is required to allow more than 7 h of total sleep time. In an analysis by household status, nurses who had young children (average age, 2.8 years) slept less and spent less time on free-time activities than did other nurses.     

Exposure of young infants to environmental tobacco smoke: breast-feeding among smoking mothers

OBJECTIVES: This study examined the degree to which breast-feeding and cigarette smoking by mothers and smoking by other household members contribute to the exposure of infants to the products of tobacco smoke. METHODS: The subjects were 330 mother-infant pairs derived from a cohort of 1000 pairs enrolled in a longitudinal study of the pulmonary effects of prenatal and postnatal smoking. The main outcome measure was corrected urinary cotinine levels. RESULTS: Urinary cotinine levels were 10-fold higher in breast-fed infants of smoking mothers than among bottle-fed infants of smoking mothers. Among infants of nonsmoking mothers, urine cotinine levels were significantly increased in infants living in homes with other smokers; in this group there was no significant difference between bottle-fed and breast-fed infants. Infants whose mothers smoked in the same room as the infant had only nonsignificant increases in cotinine levels compared with infants whose mothers restricted their smoking to other rooms. CONCLUSIONS: Breast-fed infants of smoking mothers have urine cotinine levels 10-fold higher than bottle-fed infants whose mothers smoke, suggesting that breast-feeding, rather than direct inhalation of environmental tobacco smoke, is the primary determinant of cotinine levels in infants whose mothers smoke.     

Sleeping sites, sleeping places, and presleep behavior of gibbons (Hylobates lar)

The sleeping habits of wild white-handed gibbons (Hylobates lar) were investigated to assess the risk of predation and predation-avoidance behavior. Sleeping sites were distributed throughout home ranges, including areas where they overlapped with neighbors, and appeared to be selected independently of habitat characteristics. Individuals did not build night nests or otherwise manipulate the vegetation around the sleeping place but slept on open branches. Group members usually slept in separate trees, and, except for females with infants, they never shared a sleeping place. Sleeping trees were entered several hours before dusk and were used for about 14-17 h. The majority of sleeping trees were used only once, and fewer were selected repeatedly by the same or other group members. Usually females with infants went into a sleeping tree first, then juveniles, and last were mostly subadult and adult males. Intragroup competition over access to a sleeping place was observed once. Average time difference between the first and last group member to enter a sleeping tree was 13 min. The sequence of departure from sleeping trees was more variable. Gibbon sleeping habits seem to primarily reflect adaptations to minimize predation risk. The predation-risk hypothesis was indirectly supported by observations of mobbing pythons, alarm calls given in response to birdes of prey flying low over the canopy, and more importantly by 1) the predominant use of large sleeping trees, which were among the tallest trees available, particularly by adult females with small infants and juveniles, 2) an unpredictable long-term pattern of reuse of sleeping places, and 3) inconspicuous presleep behavior.     

Dynamics of a relationship: Rhesus mother-infant ventro-ventral contact.

Examined the dynamics of the age changes in ventro-ventral contact between 19 monkey mother-infant pairs. The relative role of the infant increases with age. Correlations between medians of measures for all infants at different ages indicate that the decrease in ventro-ventral contact with age is due more immediately to changes in the mother than to changes in the infant. Data on initiation and termination of bouts suggest that earlier each member of the pair is less ready to adjust to the other's immediate motivational state than later. Correlations between measures for different dyads at particular ages are used to assess the relative contributions of mother and infants to the differences between individuals at particular ages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sudden infant death syndrome: risk factor profiles for distinct subgroups

The authors investigated risk profiles of sudden infant death syndrome (SIDS) as a function of age at death. A case-control study carried out in the Tyrol region of Austria enrolled 99 infants who died of SIDS between 1984 and 1994 and 136 randomly selected controls. Early and late SIDS (< 120 days of age vs. > or = 120 days) were defined according to the clear-cut bimodal age-at-death distribution. Inadequate antenatal care, low parental social and educational level, and the prone sleeping position were risk conditions that applied to both early and late SIDS. A marked seasonal variation (winter preponderance) was the most outstanding feature of late SIDS. A gestational age of < 37 weeks (odds ratio (OR) = 8.4, 95% confidence interval (CI) 2.6-26.0), repeated episodes of apnea (OR = 5.7, 95% CI 1.2-27.0), low birth weight (< 2,500 g) (OR = 3.4, 95% CI 1.1-11.0), a family history of sudden infant death (OR = 2.9, 95% CI 1.1-7.5), and maternal smoking during pregnancy (OR = 2.2, 95% CI 1.0-4.5) were associated with early SIDS. This study identified two distinct subgroups of SIDS infants characterized by different risk conditions and ages at death. These results underline a multiple-cause hypothesis for SIDS etiology which involves a genetic predisposition, immaturity in the first months of life, and environmental factors acting at various ages.     

Roles of living arrangements and grandmother social support in adolescent mothering and infant attachment.

Examined the roles of social support from adolescents' mothers and living arrangements in 197 adolescent mother–infant pairs. Major observational measures were teaching interactions, Home Observation for Measurement of the Environment (HOME) scores, and infant attachment security. Adolescents living with neither mothers nor partners had better teaching interactions but lower HOME scores compared with those living with mothers. High mother support was associated with more secure infant attachment only for those adolescents living with partners. When mother support was low, adolescents living alone had more secure infants than adolescents living with partners. Although parenting scores were related to differences in demographics and personal resources (intelligence and social skills), these did not appear to be responsible for the major findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infant affect and affect regulation during the still-face paradigm with mothers and fathers: the role of infant characteristics and parental sensitivity

This laboratory study examined mothers' and fathers' sensitivity during face-to-face interactions with their infants as well as infants' affective and regulatory responses during mother-infant versus father-infant still face (SF). The degree to which infant gender and temperament as well as parental sensitivity predicted SF responses was also examined. Participants included 94 healthy, primarily White, middle-class 4-month-olds and their parents. Results indicated that mothers and fathers were equally sensitive toward their infants. Infants' affect and regulatory behaviors were also significantly stable across mother- and father-infant SF situations, although several differences in mean levels of regulation emerged. Finally, the extent to which exogenous and endogenous variables predicted infant SF responses differed as a function of which affect or regulatory variable was being examined and with which parent the infant was experiencing SF.     

Impact of premature birth on the development of the infant in the family.

This article describes effects of the birth of a premature infant on the family system and focuses on how problems associated with premature birth such as infant illness, hospitalization, and immaturity can place the family at risk. New data are presented describing differences in the behavior of preterm and full-term infants and in the feelings of mothers toward their infants at 12 months. Mothers of preterm infants reported feeling overprotective toward them, were less willing to leave them with sitters, and believed that their birth had an initially negative effect on the family. Preterm infants showed less exploratory play and stayed closer to their mothers during free play. The fact that these differences are not reflected in patterns of attachment, a key measure of the mother–infant relationship, is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiologic effects of maternal smoking on breast-feeding infants

Women who smoke and breast-feed pose an unknown threat to their infants' health. In this pilot study, relationships between ingestion of nicotine in breast milk and physiologic effects in the infant were investigated. Infant physiologic effects measured were temperature, pulse, respiration, systolic blood pressure, and oxygen saturation. Five smoking and five nonsmoking mother-infant pairs were studied. Breast milk was analyzed for nicotine using gas chromatography. Breast milk from smoking mothers contained a mean of 33.1 ng/mL of nicotine while the breast milk from nonsmoking mothers contained a mean of less than 6.45 ng/mL of nicotine. Infant physiologic measures were taken before and 20 min after breast-feeding. After breast-feeding, infants of smoking mothers had a significant change in respirations and oxygen saturation while infants of nonsmoking mothers had a significant change in pulse only. Results provide a scientific basis for counseling smoking, breast-feeding mothers.     

The impact of postnatal depression and associated adversity on early mother-infant interactions and later infant outcome

The impact of maternal depression and adversity on mother-infant face-to-face interactions at 2 months, and on subsequent infant cognitive development and attachment, was examined in a low-risk sample of primiparous women and their infants. The severe disturbances in mother-infant engagement characteristic of depressed groups in disadvantaged populations were not evident in the context of postpartum mood disorder in the present study. However, compared to well women, depressed mothers were less sensitively attuned to their infants, and were less affirming and more negating of infant experience. Similar difficulties in maternal interactions were also evident in the context of social and personal adversity. Disturbances in early mother-infant interactions were found to be predictive of poorer infant cognitive outcome at 18 months. Infant attachment, by contrast, was not related to the quality of 2-month interactions, but was significantly associated with the occurrence of adversity, as well as postpartum depression.