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A Review of Research on Premature Infant-Mother Interaction
Abstract Premature infants do not often provide clear behavioral cues, making them difficult social partners. Mothers of premature infants have reported that interacting with their infant is frustrating and not very rewarding. Higher numbers of premature infants are currently surviving at younger gestational ages, but the number of premature infants that have developmental delays is not decreasing. These infants and their mothers need guidance and support for their early efforts to communicate with one another. Social interactions are considered to be important for many aspects of development. This article will review the literature on infant-mother interactions, explain the more recent findings, and provide recommendations for neonatal nurses working with premature infants and their families. n 2007 Elsevier Inc. All rights reserved. Keywords: Mother-Infant interaction, Mother-Infant relationships, Premature infants
A Review of Research on Premature Infant-Mother Interaction By Maryann Bozzette, RN, PhD
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nfant-Mother interaction is a broad category of investigation examining salient aspects of the primary social relationship. The nuances of healthy interaction have been identified through years of observing infants with their mothers. The behavior components of interactive exchanges with mothers have been noted to be different between infants born prematurely and infants born full term. Concerns that prolonged separation from their mothers due to illness and hospitalization would affect preterm infants’ ability to be successful in social circumstances prompted early work in this area. Many potential and real problems have been uncovered. However, research on preterm infantmother interaction is complex and confusing at best. The purposes of this article are to review the current studies on maternal–preterm infant interaction and to determine implications for practice.
Importance of Interaction
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From the Arizona State University College of Nursing and Healthcare Innovation, Phoenix, AZ. Address correspondences to Maryann Bozzette, RN, PhD, Arizona State University College of Nursing and Healthcare Innovation, 500 North 3rd Street, Phoenix, AZ 85004. n 2007 Elsevier Inc. All rights reserved. 1527-3369/07/0701-0174$10.00/0 doi:10.1053/j.nainr.2006.12.002
ocialization is the means by which human beings learn to live and grow within families, cultures, and societies. Beginning with their first encounter after birth, infants and mothers engage one another through gazes and gestures, and this primary relationship is the basis for all future relationships. These early dyadic interactions, which are the most common experiences for young infants, serve four major functions. They help infants to acquire an understanding of social relationships and norms, foster the development of attention, promote the acquisition of language, and facilitate the emergence of emotional regulation.1 Through interaction, infants learn to understand themselves and others and begin to see other human beings as intentional agents. Infants also learn social expectations and to anticipate the behavior of others. Early interactions teach infants to imitate, negotiate, and exert an effect on their environment.2 Critical to this early interaction is the mother’s ability to learn and attend to infant behavioral cues. Mothers often speak to their infants using an exaggerated, slow tempo, and high-pitched tone known as bmothereseQ or infant-directed speech.3 This manner of speaking to infants is universal across all cultures and has a wide range of fundamental frequencies, consisting of short phrases and fewer syllables than observed in usual conversational speech. This type of speech stimulates newborn attention, displays maternal affect, and Newborn and Infant Nursing Reviews, Vol 7, No 1 (March), 2007: pp 49-55
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Maryann Bozzette
supports language development. The prosody of infantdirected speech is musical and attractive to infants.4 In addition to modulating arousal, infants must learn to read the emotions of others.5 A major element of emotional development is regulating distress, enabling infants to tolerate high levels of arousal. Emotions such as joy are shown through facial expression and laughter, and predictable behavior such as smiles and vocal utterances are learned.6 Social and emotional development are intricately intertwined. Language acquisition is a process that includes the preverbal period when infants are learning about speech from others. The perception of speech during early infancy is a predictor of later speech development.2,7 Moreover, the quality of maternal-infant interaction is considered to be the most important contribution to social competence.8 There are several components that are considered important for successful interactions. Synchrony refers to the ability of infants and mothers to coordinate their behavior around one another. There is a rhythmic nature to successful exchanges requiring mutual involvement of social partners.9,10 This synchronized rhythm serves a regulatory function during interaction.11 Achieving synchrony during social interactions requires joint attention or coordination of attention between the dyad. Interactions during infancy are emotionally arousing and include periods of prolonged looking by the newborn, which can be very intense. A mother can bring the infant to high levels of arousal and keep his/her attention with a successful pattern or style of interaction.12 These highly charged events provide the infant with cognitive stimulation and social learning opportunities. The integration of social and emotional regulation and the growth of cognitive processes are supported by this early social experience.13 There are other important components to social interactions. Reciprocity refers to the elements that both members of the dyad contribute to social exchanges.1 Interaction takes input from each member to be successful. Turntaking is an important part of reciprocal interactions.1,12 When an infant vocalizes and does not receive a response, either verbal or visual, he/she may lose interest and look away. However, if a mother verbally responds when an infant vocalizes, it becomes a game of dgive and take.T The mother must time her utterances and expressions to those of her infant, creating a smooth-paced dyadic exchange with one another. Responses that are random, absent, chaotic, or inappropriate disrupt the interactive process. Contingent responses are vital to successful social events. Mutual gaze, gestures, body movement, and facial expression are key elements of interaction. Based on temporal pattern, predictable response, and reinforcement from their mothers, infants learn positive expressions of emotion. By 3 months of age, a pattern of interacting for
the infant-mother dyad emerges.4 Multiple studies have found direct relationships between the quality of infantmother interactions and cognitive development, language acquisition, and emotional regulation5,12,14,15
Interaction Frameworks
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nfant-mother interaction literature primarily stems from two major theoretical frameworks: attachment theory16 and the transactional model of Sameroff and Mackenzie.17 Attachment is defined as the affectionate tie of infants to their primary caregiver and is a biologically based desire for proximity.17 Attachment develops within the context of the infant and mother relationship and is influenced by the quality of interactions.18 Sensitive maternal behavior fosters secure attachment relationship, and mutually rewarding interactions reinforce the infant’s working model of the attachment figure as trustworthy and available.6 This relationship is persistent, provides security, and causes distress with separation.16 Attachment behaviors are goal-directed actions that promote proximity to the attachment figure.5 Characteristics of both the mother and infant contribute in a reciprocal manner to the quality of the dyadic relationship.1 The transactional model emphasizes the relationship of context and developmental processes. The social nature of developmental experiences is considered central for a child to grow and thrive. The ongoing development of a child is purported to be the result of continuous interaction with the environment and the experience received within the family and social context. The process is viewed as dynamic and bidirectional between the child and the salient aspects of the immediate environment.17 The most persistent and enduring person within the context of the child is the mother. The experiences provided for the infant are dependent on this primary relationship. Based on the overwhelming evidence that a child’s development is strongly influenced by early interactions, many studies of premature infant-mother dyads were conducted in the late 1970s and 1980s. These studies showed that premature infants were less attentive, less expressive, and fussier than full-term infants.19-21 The preterm infants also looked at their mothers less, vocalized less, and displayed more emotional negativity.22 Conflicting results have been found when examining maternal behavior. Some studies found that mothers of preterm infants held their infants more and provided more stimulation to their infants during free play when compared with mothers of infants born at term.23 Others have found mothers of preterm infants smile and play less with their infants and are less involved.22 The organization of interaction and the affective quality of the social exchanges
A Review of Research on Premature Infant-Mother Interaction
were much different. Mothers were reported to be intrusive and overstimulating.24 Although preterm infants seemed to be less alert, active, and responsive, their mothers appear to be more active compared with mothers of full-term infants.25 Some argue that this high level of maternal stimulation was to compensate for the infants’ lack of activity; others find it overstimulating, intrusive, and controlling. Follow-ups on infants born prematurely have shown that premature infants have a higher rate of hyperactivity attention deficit disorder and poorer expressive language skills on developmental follow-up. In addition, they have poorer motor control and lower cognitive achievement.26-28 Although there are probably many contributing factors to the delays seen in premature infants in these studies, a pattern of problematic early social behavior emerged. The relationships between material sensitivity, focused attention, and attention sharing have been demonstrated to predict later verbal and cognitive scores, as well as decreased rates of hyperactivity and compulsivity in children.29 Cohorts of prematurely born children who are now teenagers have been found to lag behind full-term infants in many areas and have more subtle problems, particularly with peer relationships and complex learning tasks as they get older. Even in the absence of neurological damage, preterm infants have lower scores on the Stanford Binet and have more difficulty with sustained attention, vocabulary, and visual perception.30 In light of the importance that early relationships have on subsequent development and what is known about preterm infant behavior, research in the area of maternalinfant interaction continues to expand and be refined. Because the current population of premature infants are born at earlier gestations and may have more complicated hospital courses, supporting the infant-mother relationship cannot be stressed enough. Since the late 1980s, an effort has been made to include both high- and low-risk infants in interaction research and to use more refined methods and analytical techniques.
Early Research on Premature Infant Interaction
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search was performed using the data bases Medline, PsyInfo, and CINAHL using keywords of motherinfant interaction, relationships, premature, and newborn with limiting factors of research. Fifteen studies, conducted since 1990, were selected for this review. Most of the studies used a quasi-experimental design with a full-term control group. Other group comparisons involved assigning the preterm infants into high- or lowrisk groups based on medical or diagnostic criteria or by gestational age, with 32 weeks used as the modal division
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between groups.31 Repeated measure designs were used in several of the studies to observe behavioral changes over time. Sampling limitations affect most of the studies reviewed. All studies used a purposive convenience sample. The major drawback to this type of sampling is that many of the mothers who refused to participate may have felt too overwhelmed or had the more medically compromised children. The samples used represented a wide variety of health states, making findings difficult to compare. Only healthy preterm infants were included in the investigations by Barratt et al,32 Schmucker et al,33 and Forcado-Guex et al.34 Finally, a small sample of less than 13 infants were studied by Reissland and Stephenson,35 Reissland et al,36 and VanBeek et al,37 which limits statistical power and makes it difficult to find differences. Our understanding of premature infant-mother interaction may be limited by not including premature infants most at risk and in sufficient numbers. The timing for observation of mother-infant interaction varies greatly. Studies using single measurement periods begin as early as 6 weeks after birth and extend to 3 months of age. The periods chosen for measurement in repeated measures design show no consistent pattern, with 3 and 6 months of age most frequently chosen. Measurement of other variables has occurred at 9, 12, and 18 months of age. Landry et al31 had the most extensive observations at five time points (6, 12, 14, 24, and 40 months). This wide range of times is difficult to interpret, and no explanations were given for the ages chosen to conduct the observations. Most of the studies that used a longitudinal design performed developmental testing with standard scales. This combined a lot of the work of earlier investigations to determine correlations between early interactions and developmental outcomes. Most of the studies used videotaped observation averaging about 30 minutes in length. Direct observation of maternal-infant interaction is considered the most comprehensive approach for behavioral research, and interaction researchers do use this technique. One study had a very brief observation period,31 whereas others were as long as 60 minutes.28 Naturalistic observations were used in eight studies. The remaining seven were conducted in a laboratory environment. This difference could affect the results of the studies because interactions normally occur spontaneously in a familiar environment. Although most of the coding schemes recorded behaviors as they occurred, scales were often used to assess maternal and infant behavior and to categorize the observation with a defined set of criteria.38,39 Several of the studies combined observation of interaction with a variety of other tools to measure maternal stress, anxiety, perinatal risk, symptoms checklist, maternal support, and
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Table 1. Research Examining Preterm Infant-Mother Interaction Design
Sample
Methods
Results 1. HRPT—lower amount of self-regulatory behaviors 2. HRPT—higher amount of inappropriate behavioral responses 3. HRPT—type and severity of medical complications negatively correlated with interaction 1. Mothers of PTs were more likely to vocalize or smile in response to infant behavior 2. PTs vocalized less and spent less time looking at their mother 1. SGA group had less smiling; delayed looking 2. PT b32 weeks had less looking behavior and less facial expression; more vocalization
Laudry et al, 1990
Three-group comparison
n = 21 FT n = 25 LRPT n = 23 HRPT
1. Observation 2. Stanford Binet IQ
Barrat et al, 1992
Two-group comparison
n = 24 LRPT n = 24 FT
1. Observation (4 months)
Van Beek et al, 1994
Four-group comparison
Beckwith and Rodning, 1996
Correlational
Laudry et al, 1998
Three-group comparison, repeated measures
n = 15 FT n = 10 SGA n b32 weeks, 8 PT n N32 weeks., 11 PT n = 51 PT
n = 112 FT n = 114 LRPT n = 73 HRPT
Reissland and Stephenson, 1998
Two-group comparison
n = 8 FT n = 5 HRPT
Gerner, 1999
Two-group comparison, repeated measures
n = 20 FT n = 20 PT
1. Videotaped observation
1. Laboratory observation (13, 20 months) 2. Bayley Scales 3. Reynell Language Scales 4. McCarthy Scale 5. Rubin (social-problem solving) 1. Observation at 6, 12, 14, 24, and 40 months
1. Observation at term and 6 weeks for vocalization
1. Videotaped observation during play (3 months) and feeding (6 months) 2. Griffith test
1. Maternal responsiveness was significantly correlated with child vocalization at 13 and 20 months and enhanced expressive, receptive language, and social problem-solving in infants 1. Infant initiating and responding increased at a slower rate in both PT groups 2. PTs performed the best with a high level of maternal support 1. Structure of interaction differed between PT and FT dyads 2. Mothers of PT infants were more active during vocalization, allowing less turn-taking by their infants 1. Maternal behavior more significant than infant behavior 2. No difference between FT and PT groups at 3 months 3. Significant relationship between infant behavior and Griffith score at 6 months
Maryann Bozzette
Author/Year
Correlational
n = 52 PT dyads
1. Observation (6 months) 2. Bayley scales 3. Interview on anxiety
Reissland et al, 1999
Two-group comparison
n = 5 FT n = 8 PT
Mcgill-Evans and Harrison, 2001
Two-group comparison
n = 49 LRPT n = 54 FT
Holditch-Davis et al, 2003
Three-group comparison
n = 41 HRPT n = 20 HRFT n = 28 LRPT
Muller-Nix et al, 2004
Correlational three-group comparison
n = 25 FT n = 19 LRPT n = 28 HRPT
Feeley et al, 2005
Correlational
n = 72 HRPT
1. NCATS 2. STAI 3. Support in Parenting Scale. *3 and 9 months
Schmucker et al, 2005
Two-group comparison
n = 79 PT infants n = 35 FT
Forcada-Guex, 2006
Two-group comparison
n = 47 PT n = 25 FT
1. Videotaped observation (3 months) 2. NBRS score 3. STAI 1. Videotaped observation (6, 18 months) 2. Symptoms checklist 3. Griffith’s development scales 4. Perinatal Risk Inventory 5. Hollingshead Index
1. Videotaped observations, feeding/changing/play at term and 6 weeks corrected age
1. NCATS (3, 12 months) 2. McCarthy Scales, Parenting Stress Index 3. Dyadic Adjustment Scale 1. Videotaped observations
1. Survey (6, 18 months) correlated age 2. Play interaction (18 months)
1. Mothers who reported high anxiety were less sensitive and more intrusive and more active during play interaction 2. No effect of maternal anxiety on Bayley score 1. Frequent maternal interrogatives 2. Imperative speech noted to be high during play; declarative speech higher during feeding; similar amount of vocalization between both groups of infants, highest during changing 1. McCarthy Motor, Receptive and Expressive Scale scores all lower for PT group 2. Maternal stress highly correlated with interaction scores 1. Mothers of LRPT infants spent less time gesturing and touching their infants 2. Interactive differences seemed to be related to infant capabilities and maternal compensation 1. Maternal stress resulted in lower maternal sensitivity and higher maternal control at 6 months in both PT groups 2. Infant compliance and compulsivity was higher at 18 months in HRPT 3. Passivity higher at 18 months in LRPT groups 1. Anxiety at 3 months was related to less sensitive maternal responsive at 9 months 2. Maternal anxiety did not decrease over the 6 months 3. Maternal perceived support was related to maternal sensitive interactions 1. PT infants had less facial expressions 2. More vocalization than full-terms 3. Maternal anxiety highly correlated with biological At 6 months, maternal sensitivity control significantly different; infant difficulty and compliance At 18 months, significantly lower personal-social scale score; lower scores in hearing and speech for PTs
FT indicates full-term infant; PT, preterm infant; HRPT, high-risk preterm infant; LRPT, low-risk preterm infant; SGA, small for gestational age; NCATS, nursing child assessment teaching scale; STAI, state trait anxiety inventory; NBRS, neurobiologic risk score.
A Review of Research on Premature Infant-Mother Interaction
Wijnoks, 1999
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relationship quality to test the correlation of these factors with interaction. Stress anxiety and perceived support were found to be significantly related to maternal sensitivity.38-40
Summary of the Research Findings
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he research that has been conducted over the last 15 years has improved in observational techniques and has examined relationships of other factors that may affect infant-mother interaction (Table 1). Preterm infants continue to have less facial expression and less looking behaviors. Some studies are reporting increased vocalization with preterm infants, but these behaviors are less likely to be contingent on maternal behavior.35,38 Mothers of preterm infants do not seem to display intrusive behavior or noncontingent behavior that was seen in past research. However, they still need to carry the major load of the interaction by vocalizing and smiling more and trying to engage their infants. Infant levels of reactivity are still lower than full-term infants. One exception was a study conducted by ForcaadoGuex et al,34,35 which reported a controlling style in their maternal sample that resulted in more compulsive compliant behavior in infants who already are more passive when interacting. Observations in this study were, however, only 10 minutes in length, and the use of global ratings for behavior may have impacted the results. Maternal perception of her child also was a predictor of later outcome.28 Mothers of premature infants have been described as viewing their infants as more vulnerable and expecting them to not perform as well as other children. Miles and Holditch-Davis41 described a pattern of maternal behavior they termed compensatory parenting. This pattern of maternal care is characterized by providing special experiences and more availability to their prematurely born child in an attempt to compensate for their neonatal experience.41 The more active behavior of the mothers of premature infants in many of these studies may have improved their interactive skills. Gerner30,37 found that at 3 months, the group of preterm infants were not different from the group of full-term infants they studied. However, by 6 months of age, the same infants began to demonstrate poorer interactive skills. The interaction observed at 6 months was correlated with lower Griffiths score, suggesting that as life becomes more demanding, maternal compensation may become less effective. Maternal sensitivity continues to be a key in successful interactions, and mothers in these samples displayed sensitive and responsive behavior. This may be the reason why many of the preterm infants did not differ from the fullterm control in many areas. Mothers used a variety of verbal
approaches that have been described as declarative, directive, or interrogative. The use of more directives in speech elicited more positive behavioral responses in the infants. Only one study found a relationship between preterm infant behaviors with neonatal risk.31 This is not surprising because previous research has shown that the social environment has a larger impact on developmental outcomes than biological risk. One investigation did find a difference between medically fragile infants and preterm infants without chronic disease. Maternal behavior was more responsive in the medically fragile group, although the nonchronically ill infants displayed more mature behaviors.29 The current literature shows that premature infants look less different from full-term infants during interactive behavior as compared with past samples. The major differences were found in looking and facial expression. The premature infants’ attempts at vocalization in many cases were higher than the full-term infants. However, when premature infants vocalized less, there were significant correlations with poorer development scores. Mothers in these studies for the most part displayed responsive and sensitive behavior toward their infants and reinforced smiles and vocalizations more frequently than did the mothers of full-term infants.42 Stress and anxiety were found to have the most significant effect on maternal behavior.39,40 Severity of illness was strongly correlated with maternal anxiety. Maternal education level also made a difference in responsive maternal behavior.25 Most of these observations occurred early in the infantmother relationship. None of the interaction observations occurred after 9 months of age. These could mean that young infants, when supported by their mothers during interactions can do well until further demands from their environment occur, and other skills such as diverting their attention to objects or locomotion becomes necessary. The establishment of early focused attention for active learning is a major task of infancy.28 As the demand for learning and interacting becomes higher, prematurely born infants may need more and different kinds of support to be successful.
Practice Implications
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any neonatal intensive care units have adopted a developmentally supportive care model to help protect infants from inappropriate and overstimulating encounters. Neonatal Individualized Developmental Care and Programs43 has made caregivers more aware of individual needs and subtle behaviors of premature infants. Mothers of premature infants are now able to learn more about their infants’ behavior and what to expect as cues,
A Review of Research on Premature Infant-Mother Interaction
particularly approach or avoidance signals. Education for mothers and support for early efforts to become acquainted with their infants and learn to understand their cues is extremely important. Supporting and reinforcing positive interaction within these dyads is an important role for nurses taking care of premature infants. Since the developmental outcomes from earlier cohorts are still showing cognitive and social problems,44,45 more work needs to be done to help infants self-regulate and integrate social and sensory stimulation.
References 1. Bornstein MH, Tamis-Lamonde CS. Mother-Infant interaction. In Fogel BA, eds. Blackwell handbook of infant development. Malden (MA): Blackwell Publishing; 2004:297-369. 2. Unknown. Socialization. Dev Sci. 2004;4:330 - 344. 3. Kuhl PK. Infant speech perception: a window on psycholinguistic development. Int J Psycholinguist. 2001;9:33 - 56. 4. Cooper RP, Aslin RN. Preferences for infant-directed speech in the first month after birth. Child Dev. 1993;61:1584 - 1595. 5. Cassidy J. Emotional regulation: influences of attachment relationships. In Fox NA, eds. Monographs of the Society for Research in Child Development. 1994;59:228 - 283 [serial no. 240]. 6. Cassidy J. The nature of the child’s ties. In Cassidy J, Shaver JR, eds. Handbook of attachment. New York (NY): Guilford Press; 1999:3-20. 7. Miceli PJ, Goeke-Morey MC, Whitman TL, et al. Brief report: birth status medical complications and social environment; Individual differences in development of preterm, very low birth weight infants. J Pediatr Psychol. 1999;25:353 - 358. 8. Kelly JF, Morisset CE, Barnard KE, et al. The influence of early mother-child interaction on preschool cognitive and linguistic outcomes in a high risk group. Infant Ment Health. 2000;27:310 - 321. 9. Lester BN, Hoffman J, Brazelton TB. The rhythmic structure of mother-infant interaction in term and preterm infants. Child Dev. 1985;56:15 - 27. 10. Feldman R, Greenbaum CW, Yirmiya N. Mother-Infant affect synchrony as an antecedent of emergence of self control. Dev Psychol. 1999;35:223 - 231. 11. Yale ME, Messinger DS, Cobo-Lewis AB. The temporal coordination of early infant communication. Dev Psychol. 1999;39: 815 - 824. 12. Hane AA, Feldstein S, Dernetz VH. The relation between coordinated interpersonal timing and maternal sensitivity in four month old infants. J Psycholinguist Res. 2003;32:525 - 539. 13. Tronick EZ. Emotions and emotional communication in infants. Am Psychol. 2003;44:112 - 119. 14. Rose SA, Feldman JF, Jankowski JJ, et al. Pathways from prematurity and infant abilities to later cognition. Child Dev. 2005;76: 1172 - 1184. 15. Lawson KR, Parrinello R, Ruff HA. Maternal behavior and infant attention. Infant Behav Dev. 2005;15:209 - 229. 16. Bowlby J. Attachment and loss, vol 1. New York (NY): Basic Books; 1973. 17. Sameroff AJ, Mackenzie MJ. Research strategies for capturing transactional models of develop the limits of the possible. Dev Psychopathol. 1973;15:613 - 640. 18. Ainsworth MDS, Bell SM, Behar MC, et al. Patterns of attachment. Hillsdale (NJ): Erbaum; 1978. 19. Goldberg S. Prematurity: effects on parent infant interaction. J Pediatr Psychol. 1978;3:137 - 144. 20. Crnic KA, Ragozin AS, Greenberg MT, et al. Social interaction and developmental competence of preterm and full term infants during the first year of life. Child Dev. 1978;54:1199 - 1210.
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21. Minde K, Whitelaw A, Brown J. Effects of neonatal complications in premature infants on early parent infant interactions. Dev Med Child Neurol. 1983;25:736 - 777. 22. Holditch-Davis D, Thoman E. The early social environment of premature and full term infants. Early Hum Dev. 1983;17:221 - 231. 23. Malatesa CZ, Grigorueav P, Lamb C, et al. Emotional socialization and expressive development in preterm and full-term infants. Child Dev. 1988;57:316 - 330. 24. Field TM. Effects of early separation, interactive deficits, and experimental manipulations on infant-mother facto-to-face interaction. Child Dev. 1986;48:763 - 777. 25. Muller-Nix C, Forcada-Guex M, Pierrehumbert B. Prematurity, maternal stress and mother-child interactions. Early Hum Dev. 1977; 79:145 - 158. 26. Lawson KR, Parrinello R, Ruff HA. Maternal behavior and infant attention. Infant Behav Dev. 2004;15:209 - 229. 27. Lawson KR, Ruff HA. Early focused attention predicts outcome of children born prematurely. Developmental and Behavioral Pediatrics. 2004;25:399 - 406. 28. Greenberg MT, Crnic KA. Longitudinal predictors of developmental status and social interaction in premature and full term infants at age two. Child Dev. 2004;59:554 - 570. 29. Holditch-Davis D, Cox MF, Miles MS. Mother-Infant interactions of medically fragile and non-chronically ill premature infants. Res Nurs Health. 1988;26:300 - 311. 30. Gerner EM. Emotional interaction in a group of preterm infants at 3 and 6 months of corrected age. Infant Child Dev. 2003;8:117 - 128. 31. Landry SH, Chapieski ML, Richardson MA. The social competence of children born prematurely: effects of medical complications and parent behaviors. Child Dev. 1999;61:1605 - 1616. 32. Barratt MS, Roach MA, Leavitt LA. Early channels of motherinfant communication: preterm and term infants. J Child Psychol Psychiatry. 1990;33:1193 - 1204. 33. Schmucker G, Brisch KH, Kohntop B, et al. The influence of prematurity, maternal anxiety and infants’ neurobiological risk on motherinfant interactions. Infant Ment Health J. 1994;26:423 - 441. 34. Forcado-Guex M, Pierehumbert B, Borghini A, et al. Early dyadic patterns of mother-infant interactions and outcomes of prematurity at 18 months. Pediatrics. 2005;118:e107-e114. 35. Reissland N, Stephenson T. Turn-taking in early vocal interactions: a comparison of premature and term infants’ vocal interaction with their mothers. Child Care Health Dev. 2006;25:447 - 456. 36. Reissland N, Sheperd J, Stephenson T. Maternal verbal interaction in different situations with infants born prematurely or at term. Infant Child Dev. 1999;8:39 - 48. 37. VanBeek Y, Hopkins B, Hoeksma JB. Development of communicative behaviors in preterm infants: the effects of birthweight status and gestational age. Infant Behav Dev. 1999;17:107 - 117. 38. Wijnroks L. Maternal recollected anxiety and mother-infant interaction in preterm infants. Infant Ment Health J. 1994;20:393 - 409. 39. Magill-Evans J, Harrison MJ. Parent-Child interactions, parenting stress, and developmental outcomes at 4 years. Child Health Care. 2001;30:135 - 150. 40. Feeley N, Gottlieb L, Zelkowitz P. Infant, mother, and contextual predictors of mother-very low birth weight infant interaction at 9 months of age. J Dev Behav Pediatr. 2001;26:24 - 33. 41. Miles MS, Holditch-Davis D. Compensatory parenting. J Pediatr Nurs. 2005;10:243 - 253. 42. Beckwith L, Rodning C. Dyadic processes between mothers and preterm infants: development at ages 2 to 5 years. Infant Ment Health J. 1996;17:322 - 333. 43. Als H, Gilkerson L, Duffy FH, et al. A three-center, randomized, controlled trial of individualized developmental care for very low birth weight preterm infants: medical neurodevelopmental, parenting and caregiving effects. Dev Behav Pediatr. 1996;24:399 - 408. 44. Gardner F, Johnson A, Yudkin P, et al. Behavioral and emotional adjustment of teenagers in mainstream school who were born before 29 weeks gestation. Pediatrics. 2003;114:676 - 682. 45. Beckwith L, Rodning C, Cohen S. Preterm children at early adolescence and continuity and discontinuity in maternal responsiveness from infancy. Child Dev. 2004;68:1198 - 1208.
A Review of Research on Premature Infant-Mother Interaction By Maryann Bozzette, RN, PhD
I
nfant-Mother interaction is a broad category of investigation examining salient aspects of the primary social relationship. The nuances of healthy interaction have been identified through years of observing infants with their mothers. The behavior components of interactive exchanges with mothers have been noted to be different between infants born prematurely and infants born full term. Concerns that prolonged separation from their mothers due to illness and hospitalization would affect preterm infants’ ability to be successful in social circumstances prompted early work in this area. Many potential and real problems have been uncovered. However, research on preterm infantmother interaction is complex and confusing at best. The purposes of this article are to review the current studies on maternal–preterm infant interaction and to determine implications for practice.
Importance of Interaction
S
From the Arizona State University College of Nursing and Healthcare Innovation, Phoenix, AZ. Address correspondences to Maryann Bozzette, RN, PhD, Arizona State University College of Nursing and Healthcare Innovation, 500 North 3rd Street, Phoenix, AZ 85004. n 2007 Elsevier Inc. All rights reserved. 1527-3369/07/0701-0174$10.00/0 doi:10.1053/j.nainr.2006.12.002
ocialization is the means by which human beings learn to live and grow within families, cultures, and societies. Beginning with their first encounter after birth, infants and mothers engage one another through gazes and gestures, and this primary relationship is the basis for all future relationships. These early dyadic interactions, which are the most common experiences for young infants, serve four major functions. They help infants to acquire an understanding of social relationships and norms, foster the development of attention, promote the acquisition of language, and facilitate the emergence of emotional regulation.1 Through interaction, infants learn to understand themselves and others and begin to see other human beings as intentional agents. Infants also learn social expectations and to anticipate the behavior of others. Early interactions teach infants to imitate, negotiate, and exert an effect on their environment.2 Critical to this early interaction is the mother’s ability to learn and attend to infant behavioral cues. Mothers often speak to their infants using an exaggerated, slow tempo, and high-pitched tone known as bmothereseQ or infant-directed speech.3 This manner of speaking to infants is universal across all cultures and has a wide range of fundamental frequencies, consisting of short phrases and fewer syllables than observed in usual conversational speech. This type of speech stimulates newborn attention, displays maternal affect, and Newborn and Infant Nursing Reviews, Vol 7, No 1 (March), 2007: pp 49-55
49
50
Maryann Bozzette
supports language development. The prosody of infantdirected speech is musical and attractive to infants.4 In addition to modulating arousal, infants must learn to read the emotions of others.5 A major element of emotional development is regulating distress, enabling infants to tolerate high levels of arousal. Emotions such as joy are shown through facial expression and laughter, and predictable behavior such as smiles and vocal utterances are learned.6 Social and emotional development are intricately intertwined. Language acquisition is a process that includes the preverbal period when infants are learning about speech from others. The perception of speech during early infancy is a predictor of later speech development.2,7 Moreover, the quality of maternal-infant interaction is considered to be the most important contribution to social competence.8 There are several components that are considered important for successful interactions. Synchrony refers to the ability of infants and mothers to coordinate their behavior around one another. There is a rhythmic nature to successful exchanges requiring mutual involvement of social partners.9,10 This synchronized rhythm serves a regulatory function during interaction.11 Achieving synchrony during social interactions requires joint attention or coordination of attention between the dyad. Interactions during infancy are emotionally arousing and include periods of prolonged looking by the newborn, which can be very intense. A mother can bring the infant to high levels of arousal and keep his/her attention with a successful pattern or style of interaction.12 These highly charged events provide the infant with cognitive stimulation and social learning opportunities. The integration of social and emotional regulation and the growth of cognitive processes are supported by this early social experience.13 There are other important components to social interactions. Reciprocity refers to the elements that both members of the dyad contribute to social exchanges.1 Interaction takes input from each member to be successful. Turntaking is an important part of reciprocal interactions.1,12 When an infant vocalizes and does not receive a response, either verbal or visual, he/she may lose interest and look away. However, if a mother verbally responds when an infant vocalizes, it becomes a game of dgive and take.T The mother must time her utterances and expressions to those of her infant, creating a smooth-paced dyadic exchange with one another. Responses that are random, absent, chaotic, or inappropriate disrupt the interactive process. Contingent responses are vital to successful social events. Mutual gaze, gestures, body movement, and facial expression are key elements of interaction. Based on temporal pattern, predictable response, and reinforcement from their mothers, infants learn positive expressions of emotion. By 3 months of age, a pattern of interacting for
the infant-mother dyad emerges.4 Multiple studies have found direct relationships between the quality of infantmother interactions and cognitive development, language acquisition, and emotional regulation5,12,14,15
Interaction Frameworks
I
nfant-mother interaction literature primarily stems from two major theoretical frameworks: attachment theory16 and the transactional model of Sameroff and Mackenzie.17 Attachment is defined as the affectionate tie of infants to their primary caregiver and is a biologically based desire for proximity.17 Attachment develops within the context of the infant and mother relationship and is influenced by the quality of interactions.18 Sensitive maternal behavior fosters secure attachment relationship, and mutually rewarding interactions reinforce the infant’s working model of the attachment figure as trustworthy and available.6 This relationship is persistent, provides security, and causes distress with separation.16 Attachment behaviors are goal-directed actions that promote proximity to the attachment figure.5 Characteristics of both the mother and infant contribute in a reciprocal manner to the quality of the dyadic relationship.1 The transactional model emphasizes the relationship of context and developmental processes. The social nature of developmental experiences is considered central for a child to grow and thrive. The ongoing development of a child is purported to be the result of continuous interaction with the environment and the experience received within the family and social context. The process is viewed as dynamic and bidirectional between the child and the salient aspects of the immediate environment.17 The most persistent and enduring person within the context of the child is the mother. The experiences provided for the infant are dependent on this primary relationship. Based on the overwhelming evidence that a child’s development is strongly influenced by early interactions, many studies of premature infant-mother dyads were conducted in the late 1970s and 1980s. These studies showed that premature infants were less attentive, less expressive, and fussier than full-term infants.19-21 The preterm infants also looked at their mothers less, vocalized less, and displayed more emotional negativity.22 Conflicting results have been found when examining maternal behavior. Some studies found that mothers of preterm infants held their infants more and provided more stimulation to their infants during free play when compared with mothers of infants born at term.23 Others have found mothers of preterm infants smile and play less with their infants and are less involved.22 The organization of interaction and the affective quality of the social exchanges
A Review of Research on Premature Infant-Mother Interaction
were much different. Mothers were reported to be intrusive and overstimulating.24 Although preterm infants seemed to be less alert, active, and responsive, their mothers appear to be more active compared with mothers of full-term infants.25 Some argue that this high level of maternal stimulation was to compensate for the infants’ lack of activity; others find it overstimulating, intrusive, and controlling. Follow-ups on infants born prematurely have shown that premature infants have a higher rate of hyperactivity attention deficit disorder and poorer expressive language skills on developmental follow-up. In addition, they have poorer motor control and lower cognitive achievement.26-28 Although there are probably many contributing factors to the delays seen in premature infants in these studies, a pattern of problematic early social behavior emerged. The relationships between material sensitivity, focused attention, and attention sharing have been demonstrated to predict later verbal and cognitive scores, as well as decreased rates of hyperactivity and compulsivity in children.29 Cohorts of prematurely born children who are now teenagers have been found to lag behind full-term infants in many areas and have more subtle problems, particularly with peer relationships and complex learning tasks as they get older. Even in the absence of neurological damage, preterm infants have lower scores on the Stanford Binet and have more difficulty with sustained attention, vocabulary, and visual perception.30 In light of the importance that early relationships have on subsequent development and what is known about preterm infant behavior, research in the area of maternalinfant interaction continues to expand and be refined. Because the current population of premature infants are born at earlier gestations and may have more complicated hospital courses, supporting the infant-mother relationship cannot be stressed enough. Since the late 1980s, an effort has been made to include both high- and low-risk infants in interaction research and to use more refined methods and analytical techniques.
Early Research on Premature Infant Interaction
A
search was performed using the data bases Medline, PsyInfo, and CINAHL using keywords of motherinfant interaction, relationships, premature, and newborn with limiting factors of research. Fifteen studies, conducted since 1990, were selected for this review. Most of the studies used a quasi-experimental design with a full-term control group. Other group comparisons involved assigning the preterm infants into high- or lowrisk groups based on medical or diagnostic criteria or by gestational age, with 32 weeks used as the modal division
51
between groups.31 Repeated measure designs were used in several of the studies to observe behavioral changes over time. Sampling limitations affect most of the studies reviewed. All studies used a purposive convenience sample. The major drawback to this type of sampling is that many of the mothers who refused to participate may have felt too overwhelmed or had the more medically compromised children. The samples used represented a wide variety of health states, making findings difficult to compare. Only healthy preterm infants were included in the investigations by Barratt et al,32 Schmucker et al,33 and Forcado-Guex et al.34 Finally, a small sample of less than 13 infants were studied by Reissland and Stephenson,35 Reissland et al,36 and VanBeek et al,37 which limits statistical power and makes it difficult to find differences. Our understanding of premature infant-mother interaction may be limited by not including premature infants most at risk and in sufficient numbers. The timing for observation of mother-infant interaction varies greatly. Studies using single measurement periods begin as early as 6 weeks after birth and extend to 3 months of age. The periods chosen for measurement in repeated measures design show no consistent pattern, with 3 and 6 months of age most frequently chosen. Measurement of other variables has occurred at 9, 12, and 18 months of age. Landry et al31 had the most extensive observations at five time points (6, 12, 14, 24, and 40 months). This wide range of times is difficult to interpret, and no explanations were given for the ages chosen to conduct the observations. Most of the studies that used a longitudinal design performed developmental testing with standard scales. This combined a lot of the work of earlier investigations to determine correlations between early interactions and developmental outcomes. Most of the studies used videotaped observation averaging about 30 minutes in length. Direct observation of maternal-infant interaction is considered the most comprehensive approach for behavioral research, and interaction researchers do use this technique. One study had a very brief observation period,31 whereas others were as long as 60 minutes.28 Naturalistic observations were used in eight studies. The remaining seven were conducted in a laboratory environment. This difference could affect the results of the studies because interactions normally occur spontaneously in a familiar environment. Although most of the coding schemes recorded behaviors as they occurred, scales were often used to assess maternal and infant behavior and to categorize the observation with a defined set of criteria.38,39 Several of the studies combined observation of interaction with a variety of other tools to measure maternal stress, anxiety, perinatal risk, symptoms checklist, maternal support, and
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Table 1. Research Examining Preterm Infant-Mother Interaction Design
Sample
Methods
Results 1. HRPT—lower amount of self-regulatory behaviors 2. HRPT—higher amount of inappropriate behavioral responses 3. HRPT—type and severity of medical complications negatively correlated with interaction 1. Mothers of PTs were more likely to vocalize or smile in response to infant behavior 2. PTs vocalized less and spent less time looking at their mother 1. SGA group had less smiling; delayed looking 2. PT b32 weeks had less looking behavior and less facial expression; more vocalization
Laudry et al, 1990
Three-group comparison
n = 21 FT n = 25 LRPT n = 23 HRPT
1. Observation 2. Stanford Binet IQ
Barrat et al, 1992
Two-group comparison
n = 24 LRPT n = 24 FT
1. Observation (4 months)
Van Beek et al, 1994
Four-group comparison
Beckwith and Rodning, 1996
Correlational
Laudry et al, 1998
Three-group comparison, repeated measures
n = 15 FT n = 10 SGA n b32 weeks, 8 PT n N32 weeks., 11 PT n = 51 PT
n = 112 FT n = 114 LRPT n = 73 HRPT
Reissland and Stephenson, 1998
Two-group comparison
n = 8 FT n = 5 HRPT
Gerner, 1999
Two-group comparison, repeated measures
n = 20 FT n = 20 PT
1. Videotaped observation
1. Laboratory observation (13, 20 months) 2. Bayley Scales 3. Reynell Language Scales 4. McCarthy Scale 5. Rubin (social-problem solving) 1. Observation at 6, 12, 14, 24, and 40 months
1. Observation at term and 6 weeks for vocalization
1. Videotaped observation during play (3 months) and feeding (6 months) 2. Griffith test
1. Maternal responsiveness was significantly correlated with child vocalization at 13 and 20 months and enhanced expressive, receptive language, and social problem-solving in infants 1. Infant initiating and responding increased at a slower rate in both PT groups 2. PTs performed the best with a high level of maternal support 1. Structure of interaction differed between PT and FT dyads 2. Mothers of PT infants were more active during vocalization, allowing less turn-taking by their infants 1. Maternal behavior more significant than infant behavior 2. No difference between FT and PT groups at 3 months 3. Significant relationship between infant behavior and Griffith score at 6 months
Maryann Bozzette
Author/Year
Correlational
n = 52 PT dyads
1. Observation (6 months) 2. Bayley scales 3. Interview on anxiety
Reissland et al, 1999
Two-group comparison
n = 5 FT n = 8 PT
Mcgill-Evans and Harrison, 2001
Two-group comparison
n = 49 LRPT n = 54 FT
Holditch-Davis et al, 2003
Three-group comparison
n = 41 HRPT n = 20 HRFT n = 28 LRPT
Muller-Nix et al, 2004
Correlational three-group comparison
n = 25 FT n = 19 LRPT n = 28 HRPT
Feeley et al, 2005
Correlational
n = 72 HRPT
1. NCATS 2. STAI 3. Support in Parenting Scale. *3 and 9 months
Schmucker et al, 2005
Two-group comparison
n = 79 PT infants n = 35 FT
Forcada-Guex, 2006
Two-group comparison
n = 47 PT n = 25 FT
1. Videotaped observation (3 months) 2. NBRS score 3. STAI 1. Videotaped observation (6, 18 months) 2. Symptoms checklist 3. Griffith’s development scales 4. Perinatal Risk Inventory 5. Hollingshead Index
1. Videotaped observations, feeding/changing/play at term and 6 weeks corrected age
1. NCATS (3, 12 months) 2. McCarthy Scales, Parenting Stress Index 3. Dyadic Adjustment Scale 1. Videotaped observations
1. Survey (6, 18 months) correlated age 2. Play interaction (18 months)
1. Mothers who reported high anxiety were less sensitive and more intrusive and more active during play interaction 2. No effect of maternal anxiety on Bayley score 1. Frequent maternal interrogatives 2. Imperative speech noted to be high during play; declarative speech higher during feeding; similar amount of vocalization between both groups of infants, highest during changing 1. McCarthy Motor, Receptive and Expressive Scale scores all lower for PT group 2. Maternal stress highly correlated with interaction scores 1. Mothers of LRPT infants spent less time gesturing and touching their infants 2. Interactive differences seemed to be related to infant capabilities and maternal compensation 1. Maternal stress resulted in lower maternal sensitivity and higher maternal control at 6 months in both PT groups 2. Infant compliance and compulsivity was higher at 18 months in HRPT 3. Passivity higher at 18 months in LRPT groups 1. Anxiety at 3 months was related to less sensitive maternal responsive at 9 months 2. Maternal anxiety did not decrease over the 6 months 3. Maternal perceived support was related to maternal sensitive interactions 1. PT infants had less facial expressions 2. More vocalization than full-terms 3. Maternal anxiety highly correlated with biological At 6 months, maternal sensitivity control significantly different; infant difficulty and compliance At 18 months, significantly lower personal-social scale score; lower scores in hearing and speech for PTs
FT indicates full-term infant; PT, preterm infant; HRPT, high-risk preterm infant; LRPT, low-risk preterm infant; SGA, small for gestational age; NCATS, nursing child assessment teaching scale; STAI, state trait anxiety inventory; NBRS, neurobiologic risk score.
A Review of Research on Premature Infant-Mother Interaction
Wijnoks, 1999
53
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Maryann Bozzette
relationship quality to test the correlation of these factors with interaction. Stress anxiety and perceived support were found to be significantly related to maternal sensitivity.38-40
Summary of the Research Findings
T
he research that has been conducted over the last 15 years has improved in observational techniques and has examined relationships of other factors that may affect infant-mother interaction (Table 1). Preterm infants continue to have less facial expression and less looking behaviors. Some studies are reporting increased vocalization with preterm infants, but these behaviors are less likely to be contingent on maternal behavior.35,38 Mothers of preterm infants do not seem to display intrusive behavior or noncontingent behavior that was seen in past research. However, they still need to carry the major load of the interaction by vocalizing and smiling more and trying to engage their infants. Infant levels of reactivity are still lower than full-term infants. One exception was a study conducted by ForcaadoGuex et al,34,35 which reported a controlling style in their maternal sample that resulted in more compulsive compliant behavior in infants who already are more passive when interacting. Observations in this study were, however, only 10 minutes in length, and the use of global ratings for behavior may have impacted the results. Maternal perception of her child also was a predictor of later outcome.28 Mothers of premature infants have been described as viewing their infants as more vulnerable and expecting them to not perform as well as other children. Miles and Holditch-Davis41 described a pattern of maternal behavior they termed compensatory parenting. This pattern of maternal care is characterized by providing special experiences and more availability to their prematurely born child in an attempt to compensate for their neonatal experience.41 The more active behavior of the mothers of premature infants in many of these studies may have improved their interactive skills. Gerner30,37 found that at 3 months, the group of preterm infants were not different from the group of full-term infants they studied. However, by 6 months of age, the same infants began to demonstrate poorer interactive skills. The interaction observed at 6 months was correlated with lower Griffiths score, suggesting that as life becomes more demanding, maternal compensation may become less effective. Maternal sensitivity continues to be a key in successful interactions, and mothers in these samples displayed sensitive and responsive behavior. This may be the reason why many of the preterm infants did not differ from the fullterm control in many areas. Mothers used a variety of verbal
approaches that have been described as declarative, directive, or interrogative. The use of more directives in speech elicited more positive behavioral responses in the infants. Only one study found a relationship between preterm infant behaviors with neonatal risk.31 This is not surprising because previous research has shown that the social environment has a larger impact on developmental outcomes than biological risk. One investigation did find a difference between medically fragile infants and preterm infants without chronic disease. Maternal behavior was more responsive in the medically fragile group, although the nonchronically ill infants displayed more mature behaviors.29 The current literature shows that premature infants look less different from full-term infants during interactive behavior as compared with past samples. The major differences were found in looking and facial expression. The premature infants’ attempts at vocalization in many cases were higher than the full-term infants. However, when premature infants vocalized less, there were significant correlations with poorer development scores. Mothers in these studies for the most part displayed responsive and sensitive behavior toward their infants and reinforced smiles and vocalizations more frequently than did the mothers of full-term infants.42 Stress and anxiety were found to have the most significant effect on maternal behavior.39,40 Severity of illness was strongly correlated with maternal anxiety. Maternal education level also made a difference in responsive maternal behavior.25 Most of these observations occurred early in the infantmother relationship. None of the interaction observations occurred after 9 months of age. These could mean that young infants, when supported by their mothers during interactions can do well until further demands from their environment occur, and other skills such as diverting their attention to objects or locomotion becomes necessary. The establishment of early focused attention for active learning is a major task of infancy.28 As the demand for learning and interacting becomes higher, prematurely born infants may need more and different kinds of support to be successful.
Practice Implications
M
any neonatal intensive care units have adopted a developmentally supportive care model to help protect infants from inappropriate and overstimulating encounters. Neonatal Individualized Developmental Care and Programs43 has made caregivers more aware of individual needs and subtle behaviors of premature infants. Mothers of premature infants are now able to learn more about their infants’ behavior and what to expect as cues,
A Review of Research on Premature Infant-Mother Interaction
particularly approach or avoidance signals. Education for mothers and support for early efforts to become acquainted with their infants and learn to understand their cues is extremely important. Supporting and reinforcing positive interaction within these dyads is an important role for nurses taking care of premature infants. Since the developmental outcomes from earlier cohorts are still showing cognitive and social problems,44,45 more work needs to be done to help infants self-regulate and integrate social and sensory stimulation.
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