Kangaroo mother care and the bonding hypothesis.

BACKGROUND
Based on the general bonding hypothesis, it is suggested that kangaroo mother care (KMC) creates a climate in the family whereby parents become prone to sensitive caregiving. The general hypothesis is that skin-to-skin contact in the KMC group will build up a positive perception in the mothers and a state of readiness to detect and respond to infant's cues.


METHOD
The randomized controlled trial was conducted on a set of 488 infants weighing <2001 g, with 246 in the KMC group and 242 in the traditional care (TC) group. The design allows precise observation of the timing and duration of mother-infant contact, and takes into account the infant's health status at birth and the socioeconomic status of the parents. BONDING ASSESSMENT: Two series of outcomes are assessed 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 of the mother and child's responsivity to each other during breastfeeding at 41 weeks of gestational age.


INTERVENTIONS
KMC has three components. The first is the kangaroo position. Once the premature infant has adapted to extrauterine life and is able to breastfeed, he is positioned on the mother's chest, in a upright position, with direct skin-to-skin contact. The second component is kangaroo nutrition. Although breastfeeding is the prime source of nutrition, infants also may receive preterm formula whenever necessary and vitamin supplements. The third component is the clinical control; infants are monitored on a regular basis, daily until they are gaining at least 20 g per day. Afterward, weekly clinic visits are scheduled until term, which constitutes the ambulatory minimal neonatal care. In the TC group, infants are kept in incubators until they are able to self-regulate their temperature and are thriving (ie, have an appropriate weight gain). Infants are discharged according to current hospital practice, usually not before their weight is approximately 1700 g. Afterward, as with the KMC group, weekly clinic visits are scheduled until term.


RESULTS
We observed a change in the mothers' perception of her child, attributable to the skin-to-skin contact in the kangaroo-carrying position. This effect is related to a subjective "bonding effect" that may be understood readily by the empowering nature of the KMC intervention. Moreover, in stressful situations when the infant has to remain in the hospital longer, mothers practicing KMC feel more competent than do mothers in the TC group. This is what we call a resilience effect. In these stressful situations we also found a negative effect on the feelings of received support of mothers practicing KMC. We interpret this as an isolation effect. To thwart this deleterious effect, we would suggest adding social support as an integral component of KMC. The observations of the mothers' sensitive behavior did not show a definite bonding effect, but rather a resilience effect. This is attributable to the KMC intervention; mothers practicing KMC were more responsive to an at-risk infant whose development has been threatened by a longer hospital stay. Otherwise, we observed that the mothers (in both the KMC group and the TC group) had behavioral patterns that were adapted to the child's at-risk health status and to the precarious condition of some premature infants requiring intensive care. We conclude that the infant's health status may be a more prominent factor in explaining a mother's more sensitive behavior, which overshadows the kangaroo-carrying effect.


CONCLUSION
These results suggest that KMC should be promoted actively and that mothers should be encouraged to use it as soon as possible during the intensive care period up to the 40 weeks of gestational age. Thus, KMC should be viewed as a means of humanizing the process of g