Kangaroo mother care and the bonding hypothesis

Kangaroo Mother Care and the Bonding Hypothesis

PEDIATRICS Vol. 102 No. 2 August 1998, p. e17

Réjean Tessier*, Marta Cristo, Stella Velez, Marta Girón, SW; Zita Figueroa de Calume, Juan G. Ruiz-Paláez, Yves Charpak, and Nathalie Charpak

From the *School of Psychology, Laval University, Québec, Canada; ISS-World Lab, Kangaroo Mother Care Program, Clinica del Nino, Santa Fe de Bogotá, Colombia; - Clinical Epidemiology Unit, Faculty of Medicine, Javeriana University, Santa Fe de Bogotá, Colombia; and EVAL (Institut pour l'Évaluation dans le domaine Médical, Médico-social et de Santé Publique), Paris, France.

METHOD

Population and Sample • KMC and TC Interventions • Outcome Variables• Control Variables • References •

Population and Sample

This study is part of a randomized, controlled trial conducted in Bogotá, Colombia,3 involving 1084 infants that weighed <2001 grams and who were born between September 1993 and September 1994 at Clinica San Pedro Claver. Of these, 746 were eligible according to the following inclusion and exclusion criteria. An infant and mother were eligible if the mother or a relative was willing to follow instructions, and if the infant had overcome all major adaptation problems to extrauterine life, had a positive weight gain, and suckled and swallowed properly. Infant-mother dyads were excluded if the infant died; had been referred to another institution; had lethal or major malformations; had sequelae arising from perinatal problems (severe hypoxic-ischemic encephalopathy, pulmonary hypertension, etc); or had been abandoned or given for adoption. Eligible mother-infant dyads were randomized according to a stratified block randomization procedure prepared in advance. Three strata were defined, based on weight at birth (<1200 g; 1200 to 1499 g; 1500 to 2000 g), and blocks of four infants (2 KMC and 2 TC control infants) were prepared using a random number table. Of the initial group of 746 infants, 153 (20.1%) were lost because of technical problems with the video sequences (same rates in both the KMC group and the TC group); 17 (2.3%) died between eligibility and 41 weeks of gestational age (the death rate was similar in both groups3); 61 (8.2%) abandoned the study; and 27 (3.6%) mothers practicing KMC did not follow instructions to carry the infant. Consequently, the study group was reduced to 488 mother-infant dyads, 246 in the KMC group and 242 in the TC group. We compared the final group of 488 dyads with the subgroup of 258 nonparticipating dyads. We found no differences in the families’ sociodemographic backgrounds or in the characteristics of the pregnancy or labor. Moreover, the neonatal variables were all the same, except that infants in the nonparticipating group were slightly heavier at birth (by 56 g) (data not shown).

The two groups were randomized before seeking consent to participate, and informed consent forms were not completed by parents of infants assigned to the TC group. This procedure, proposed by Meinert and Tonascia,19 was chosen because early discharge is very appealing to parents, and it is very likely that many of the families would have asked to be assigned to the KMC group. This procedure was accepted by the ethics committee because those assigned to the control group received the usual care provided at the participant institution.

KMC and TC Interventions

KMC has three components. 1, 3 The first is the kangaroo position. Once premature infants have adapted to extrauterine life and can breastfeed, they are discharged and positioned in an upright position on the mother’s chest, with direct skin-to-skin contact. It should be pointed out that the kangaroo position has the same temperature-regulating properties of the incubator. The mother and infant may then be released from the hospital regardless of the infant’s actual weight or gestational age. Infants are maintained continuously in this position, 24 hours a day, until they demonstrate, behaviorally, that they are ready to leave, usually at ~37 to 38 weeks’ gestational age. Other caregivers (eg, the father, grandparents, etc) may alternate with the mother as a kangaroo position provider. This first component is the related most directly to this study’s psychological hypothesis.

The second component is kangaroo nutrition. Although breastfeeding is the prime source of nutrition, infants also may receive preterm formula and vitamin supplements when necessary. The third component is the clinical control: infants are monitored on a regular basis daily until a weight gain of at least 20 g per day is observed. Afterward, weekly visits are scheduled until term (40 weeks’ gestational age), which constitutes the ambulatory minimal neonatal care.

In the TC group, infants are kept in incubators until they can regulate their temperature and are thriving (ie, have an appropriate weight gain). They are discharged in accordance to current hospital practice, that is, usually not before their weight is ~1700 g. This period is when infants no longer need intensive care, and stay in hospital is the only difference between them and infants in the KMC group. Otherwise, as with those in the KMC group, mothers are encouraged to visit and breastfeed their infant as early as possible during the inpatient period, and infants receive preterm formula and vitamin supplements when necessary. These infants received the same outpatient care and follow-up as infants in the KMC group. Therefore, the TC intervention includes an inpatient period (from eligibility to discharge) as well as an at-home period lasting until term.

Outcome Variables

The Mother’s Perception of Premature Birth Questionnaire

Essentially, this questionnaire addresses three aspects of the mother’s life linked to experiencing a premature birth. It has been designed based on interviews with the mothers and takes into account published empirical research on the experience of prematurity. From a theoretical aspect, the questionnaire includes three general domains: 1) the mother’s social, family, and institutional environment -- and in particular, her perception of the respective support received from these three environments; 2) the mother’s feelings and worries about her LBW infant (anxiety, guilt); and 3) the mother’s sense of competence and confidence in her ability to nurture her premature infant. These three domains are measured using a Likert scale (1 to 5), 24 hours after birth and when the infant has reached 41 weeks’ gestational age. Although the questions varied somewhat in the 24-hour and 41-week questionnaires (in terms of the contextual difference), the factor analyses conducted on the sample of 488 families suggested the presence of the same three score model at each time point: mother’s sense of competence, perception of social support, and feeling of stress and worry. These factor scores are used in this study.

The Nursing Child Assessment Feeding Scale

This scale measures the emotional bond between mother and child, and consists of 76 binary items organized according to six conceptual subscales. Four of them describe the mother’s behavior toward her infant: sensitivity to the infant, response to infant’s distress, and behaviors related to socioemotional, and cognitive stimulation of the infant. The remaining two subscales describe the infant’s response to the mother (clarity of cues, responsiveness). The validity and reliability of the scale are well established,20 and interrater agreement is 0.85 in this study.

Control Variables

Many control variables have been introduced to optimize data interpretation. They include gestational age at birth, gender, weight, height and head circumference at birth; intrauterine growth diagnosis according to the Lubchenco classification; parity; Apgar score at 1 and 5 minutes; diagnoses at eligibility time; age, weight, height, and head circumference at eligibility; family sociodemographic descriptors; and pregnancy and delivery variables.

Procedures

All infants were evaluated at birth, at time of eligibility, and at term by a team of pediatricians, nurses, social workers, and psychologists. All mothers (1084) participated in a structured interview after 24 hours in the hospital and after their respective infants reached a gestational age of 41 weeks, for the dyads remaining in the study. A 15-minute interaction-feeding sequence was videotaped in a small room near the clinic when the parent and child attended the follow-up clinic at gestational age 41 weeks. These sequences were scored according to the Nursing Child Assessment Feeding Scale. Performing the entire study under completely blind conditions was not possible because during the LBW follow-up clinic, the psychologists involved with the patients also were both observers during the videotaping as well as final evaluators. However, the large number of subjects, the 1-year interval before videotaping, and the coding procedure ensure that the study was performed under quasiblind conditions.

Kangaroo Mother Care and the Bonding Hypothesis

PEDIATRICS Vol. 102 No. 2 August 1998, p. e17

Réjean Tessier*, Marta Cristo, Stella Velez, Marta Girón, SW; Zita Figueroa de Calume, Juan G. Ruiz-Paláez, Yves Charpak, and Nathalie Charpak

Objectives and Hypothesis

In this study, mothers in a KMC group practicing 24-hour-a-day skin-to-skin contact were compared with mothers in a traditional care group (TC). Furthermore, infants in the TC group were kept in incubators at the minimal care unit until they met standard discharge criteria, after which they were sent home and received the same outpatient care as infants in the KMC group (see below). This randomized, controlled trial permits timing of mother-infant contact to be determined (1 to 65 days after birth) and takes into account the infant’s health status and the marital and socioeconomic status of the parents. Because high-risk infant births can hinder the development of maternal attachment, such as in the mothering-disability syndrome that threatens the survival of neonates,17,18 the KMC intervention in this context could produce major changes in the mothers’ attachment behaviors and perceptions.

Two series of outcomes are taken as manifestations of a mother’s attachment behavior. The first is the mother’s feelings and perceptions of her premature birth experience, including her sense of competence, feelings of worry and stress, and perception of social support. The second outcome is derived from observations made of the mother and child’s responsiveness to each other during breastfeeding, at the gestational age of 41 weeks. Our general hypothesis is that the skin-to-skin contact practiced in the KMC group will induce a positive perception and a state of readiness in the mother to detect and respond to infant cues. We suggest that KMC will be most effective

when the interval between birth and start of intervention is short; and
when the infant’s health is fragile and intensive care during hospitalization is needed.

Kangaroo Mother Care and the Bonding Hypothesis

PEDIATRICS Vol. 102 No. 2 August 1998, p. e17

Réjean Tessier*, Marta Cristo, Stella Velez, Marta Girón, SW; Zita Figueroa de Calume, Juan G. Ruiz-Paláez, Yves Charpak, and Nathalie Charpak

The Bonding Hypothesis

After the publication of Klaus and colleagues’ work,13,14 the concept of bonding has withstood the test of time, and the perception that instantaneous bonding is a vital component of the "ideal" birth experience has dominated our perception of childbirth. The clinical benefits of humanizing the process of giving birth, resulting from the changes in intensive care nursery that Klaus et al supported, were widely recognized and accepted. On the other hand, although 25 years have passed since Klaus et al.’s article was published and despite a plethora of studies in the 1970s and 1980s on early mother-child bonding, controversial comments, critiques, and confusing conclusions abound. The importance of early contact between the mother and infant first was reviewed by Lamb and Hwang15 in 1982 and critically analyzed by Diane Eyer16 in 1992. Despite its apparent clinical importance, the bonding hypothesis still is not recognized universally.

Is there a postnatal bonding effect? Based on the literature and available empirical data, nothing is less obvious: the duration of both the bonding period and its effects are unknown. Furthermore, the nature of the attachment behavior is not clearly defined. On the other hand, in skin-to-skin contact, short-term effects (lasting for up to 1 month) are observed, and the mother’s perception and behavior are different from those observed in the control groups. For all these reasons, replicate studies would be very useful to clarify some of the unanswered questions noted above.

KMC and the Bonding Hypothesis

Theoretically, KMC is based on the idea that a bonding effect is induced by early skin-to-skin contact between the child and its caregiver. After Bogotá’s recent tradition and drawing on the well known importance of early social interactions with the caregiver, such as holding, touching, and eye contact, some neonatal intensive care units use KMC to add an emotional complementary dimension to routine care. This approach is an attempt to humanize care given during the period in the neonatal intensive care unit (NICU) and to improve both communication and attachment between caregiver and child. Moreover, KMC should be seen as a means to ensure the successful discharge of a fragile infant from the NICU by enhancing family caregiving during the post-NICU period.

Kangaroo Mother Care and the Bonding Hypothesis

PEDIATRICS Vol. 102 No. 2 August 1998, p. e17

Réjean Tessier*, Marta Cristo, Stella Velez, Marta Girón, SW; Zita Figueroa de Calume, Juan G. Ruiz-Paláez, Yves Charpak, and Nathalie Charpak

INTRODUCTION

Kangaroo mother care (KMC) was first suggested in 1978 by Dr Edgar Rey in Bogotá, Colombia. It was developed initially as a way of compensating for the overcrowding and scarcity of resources in hospitals caring for low birth weight (LBW) infants.1, 2The term KMC is derived from practice similarities to marsupial caregiving, ie, the premature infant is kept warm in the maternal pouch and close to the breasts for unlimited feeding. Dr Hector Martinez and Dr Luis Navarette continued and built on Rey’s seminal work. In addition, since the end of the 1980s, a new KMC model has been developed by a team from the Colombian Department of Social Security and the World Laboratory (a Swiss nongovernmental organization).3 Some developing countries4,5 with funding from UNICEF, and developed countries including the United States,6 England,7 France,8Sweden,9 Canada,10 and the Netherlands11 have introduced skin-to-skin contact in nurseries for premature infants. It is generally hypothesized that this type of care promotes physiological stability and enhances the parent-child relationship.

Most of the published studies on skin-to-skin contact have focused on the physiological benefits to the infant. Only a few have addressed the parent and child’s psychological well-being (for a review, see Anderson12and Charpak et al1). The objective of this study is to investigate the impact of KMC on the mother’s perception of giving birth as well as on the mother and child’s responsiveness to each other. Based on the general bonding hypothesis, we suggest that KMC creates a family atmosphere in which parents become more exposed to sensitive caregiving.

Subcategories

Results

Page 2 of 3