But can it work in babies born as early as 28 weeks' gestation? The answer
is a qualified yes, Johnston and colleagues now find.
These "very preterm" babies do seem to feel a bit less pain when
cuddled by their mothers while nurses obtain blood samples from a heelstick.
Even more importantly, the babies recover from the painful experience much
faster when cuddled.
"The pain response in very preterm neonates appears to be reduced by
skin-to-skin maternal contact," Johnston says in a news release. "This
response [to cuddling] is not as powerful as it is in older preterm babies, but
the shorter recovery time using kangaroo mother care is important in helping
maintain the baby's health."
Kangaroo mother care was invented in 1978 by Colombian pediatrician Edgar
Rey. Faced with a shortage of incubators, Rey found that mothers could use
their own bodies to warm premature infants. Years of study show the technique
to be at least as safe and effective as incubators, and it lessens mothers' anxiety while promoting
mother/infant bonding and breastfeeding.
The technique calls for the tiny child to be held upright between the
mothers' breasts and covered with a blanket. Because the child must be held
upright against warm skin 24 hours a day, mothers can share kangaroo care with
fathers and others.
The Johnston study enrolled babies who needed at least two blood draws via
heelstick. They performed one heelstick while the baby lay in an incubator, and
another while the baby was being held in kangaroo care. The babies' facial
expressions were videotaped, and researchers monitored their vital signs.
It's hard to judge exactly how much pain a premature infant is feeling. The
researchers used a scale called the premature infant pain profile, a composite
measure of physiological and behavioral signs.
Unlike the older preemies, who felt less pain throughout the procedure when
given kangaroo care, the very preterm infants in the current study felt less
pain only 90 seconds after the heelstick when cuddled by their mothers. Even
then, they had only 2 fewer points of pain on the 21-point scale.
More importantly, the very preterm babies recovered from the painful
heelstick about a minute faster when held kangaroo-style than when left in the
incubator. That's a sign the babies' bodies are beginning to self-regulate, a
process known as homeostasis.
"The ability to recover quickly is a sign of ability to maintain
homeostasis, a major task that the very preterm neonate must accomplish in
order to grow and develop," Johnston and colleagues write.
"Mothers should be offered kangaroo mother care as neonatal
intensive-care unit policy, not only to be close to their infant, but also to
provide comfort," they add.
The findings appear in the April 23 issue of the online journal BMC