Canadian researchers found that skin to skin contact with their mothers, often termed kangaroo mother care (KMC), helped very preterm babies born between 28 and 32 weeks of pregnancy by reducing the stress of painful medical procedures.
The study is published in the online issue of the BioMed Central journal BMC Pediatrics and is the work of researchers at McGill University in Montreal, Canada, and other colleagues in Canada.
Neonatal units often use the “heel prick” test to recover blood to test blood sugar. Babies can take several minutes to recover from such a procedure, and the longer they are stressed, the higher the risk to their health.
There is some evidence that skin to skin contact or KMC lessens the pain response in full term and moderately preterm babies, but there are no studies on how very preterm babies may benefit.
Corresponding and lead author Dr Celeste Johnston who is James McGill Professor and Associate Director for Research at the McGill School of Nursing said, in a statement reported by the BBC, that:
“The pain response in very preterm neonates appears to be reduced by skin-to-skin maternal contact.”
Using a single-blind randomized crossover study, Johnston and colleagues performed the heel prick test on 61 babies between 28 and nearly 32 weeks gestational age at three neonatal intensive care units (NICUs) in Canada.
Single blind means the people handling the babies knew what was happening and why, and crossover means the same babies went through the experimental condition and the “control” condition.
Thus, in the experimental condition, a baby would be held in KMC for 15 minutes before and during the heel lance or heel prick test. In the control condition, a baby would be just lying down swaddled in a blanket in the incubator when the test was carried out.
The researchers measured pain response using the Premature Infant Pain Profile (PIPP) which assesses three facial expressions (these were filmed continuously), maximum heart rate, minimum oxygen saturation in blood from baseline at 30-second intervals. They also used a secondary measure, the time for the heart rate to return to baseline.
The results showed that:
- PIPP scores 90 seconds after the heel prick test were signficantly lower when the babies were held in KMC.
- Non-significant differences favouring KMC also occurred at 30, 60 and 120 seconds.
- Time to recover was a significan minute shorter (123 versus 193 seconds) when babies had the heel prick while in KMC than when they were not.
- Facial actions during KMC were signficantly lower at all intervals after the heel prick test, with a two-fold difference at 120 seconds.
- And heart rate was also significantly lower across the first 90 seconds when the babies were in KMC.
The researchers concluded that:
“Very preterm neonates appear to have endogenous mechanisms elicited through skin-to-skin maternal contact that decrease pain response, but not as powerfully as in older preterm neonates.”
They wrote that KMC for managing pain in preterm babies “is obviously cost-effective and has now been shown to be effective in infants from 28 weeks through term”, and suggested that it should be policy for NICUs to offer KMC to mothers, not only to help them feel closer to their babies, but also for the benefit of the babies’ health.
“The shorter recovery time in KMC is clinically important in helping maintain homeostasis,” wrote the authors.
“Kangaroo mother care diminishes pain from heel lance in very preterm neonates: A crossover trial.
C Celeste Johnston, Francoise Filion, Marsha Campbell-Yeo, Celine Goulet, Linda Bell, Kathryn McNaughton, Jasmine Byron, Marilyn Aita, G Allen Finley, and Claire-Dominique Walker.
BMC Pediatrics 2008, 8:13
First published online 24 April 2008.
Featured as cover article 24 May 2008 (full text).
doi:10.1186/1471-2431-8-13
Sources: journal abstract, BBC News.
Written by: Catharine Paddock, PhD