Breastfeeding and kangaroo care: biobehavioral measures of dyadic bonding, infant cortical maturation, and infant HPA reactivity

The current study examined the effects of kangaroo care on breastfeeding
practices, infant stress reactivity, and biobehavioral measures of mother-infant bonding
across the first 3 months postpartum. Additionally, the role of breastfeeding in infant
cortical maturation in the frontal lobe was examined. Thirty two mother-infant dyads
participated in the current study; 16 mother-infant dyads were randomly assigned to the
kangaroo care group and 17 mother-infant dyads were assigned to the control group.
Mothers in the kangaroo care group received training on proper kangaroo care procedures
by a trained administrator during the first 1-2 weeks postpartum. Mothers in the kangaroo
care group were asked to use the kangaroo care procedure for 1 hour per day for 6 weeks. Maternal perceptions of fetal attachment, mood, feeding intentions, and urinary
oxytocin measurements were assessed prenatally. At a newborn visit, infant
neurobehavioral functioning and urinary oxytocin measurements were assessed. Maternal
mood and feeding practices were also assessed at the newborn visit. At 3 months
postpartum, mother-infant dyads were assessed on urinary oxytocin measurements.
Mother-infant dyads were recorded during a play session and feeding session. Infant
baseline EEG recordings were taken over a 5 minute period. Infant cortisol
measurements were collected from infant saliva before and after a mild behavioral
stressor, an infant arm restraint procedure. Maternal perceptions of postpartum bonding,
mood, infant temperament, and feeding practices were also assessed. Results indicate that
kangaroo care produced medium to large effects on cortisol reactivity, dyadic bonding,
and breastfeeding practices if kangaroo care was practiced for the recommended amount
of time. Kangaroo care produced medium to large effects on oxytocin levels in motherinfant
dyads regardless of use. Cortical measures of infant frontal activity indicated that
all infants in the samples displayed functional maturity of the frontal lobe. Kangaroo care
can be used a viable, low-cost tactile procedure that can be implemented after birth to aid
in breastfeeding practices, mother-infant bonding, and lower infant stress reactivity.
Infants in the study who received at least one breastfeeding session displayed advanced
patterns of frontal activation. Further study is needed to determine if peripheral oxytocin
measurements are 1) reliable and 2) are indicative of dyadic bonding behaviors.