Premature infants may have trouble making the transition to oral feeding. (Claude Paris/Canadian Press/AP)

Playing lullabies to premature infants may help lessen their pain and encourage normal feeding, say researchers in Alberta who reviewed research on the topic.

Music, such as lullabies, classical works by Mozart and nursery rhymes, are increasingly used in neonatal units across North America because it's thought to calm infants and parents, help the babies gain weight faster and shorten hospital stays, but there hasn't been strong evidence to back up the idea.

In Thursday's online edition of the Archives of Disease in Childhood, Dr. Manoj Kumar of the University of Alberta and his colleagues analyzed data from nine reviewed studies published between 1989 and 2006.

• Six looked at playing music to babies during painful procedures such as circumcision and heel pricks to obtain blood samples.
• One considered the effect of playing music on feeding rates as infants moved from feeding by nasal or gastric tubes to bottle feeding.
• Two looked at the effect of music on physiology and behaviour.

A study that looked at using music during circumcision showed benefits for the infants' heart rate, oxygen saturation and pain, and benefits for behaviour and pain were also found in heel prick studies.

Higher quality trials needed

"[T]here is preliminary evidence to suggest that music may have beneficial effects in terms of physiological parameters, behavioural states and pain reduction during painful medical procedures," the study's authors concluded.

The benefits need to be confirmed in well-designed, high quality trials, they added, noting the range of infants studied made it difficult to reach definitive conclusions.

Dr. F. Sessions Cole, director of newborn medicine and head of the neonatal intensive care unit at St. Louis Children's Hospital, agreed the jury is still out.

"I know many of us would like this music-based strategy to work to reduce use of pain medications and to improve outcomes of these fragile, high-risk infants," Cole told HealthDay News.

"However, based on this article, evaluation of the use of music for pain relief among sick newborn infants is experimental at best and will require more carefully designed, methodologically rigorous strategies before any kind of conclusion about its usefulness can be made."

The rate of pre-term births in Canada has increased since the early 1990s, which may result in increased risk of long hospitalizations and complications,as well as long-term physical effects on the children and extra costs to the health-care system, according to a report published in January by the Canadian Institute for Health Information.

In 2006-2007, the Canadian pre-term birth rate was 8.1 per cent, or almost 29,000 births, up from about 6.6 per cent in the early 1990s.

Risk factors such as maternal smoking, infections in the womb, delayed child-bearing, and use of reproductive technologies could be contributing to the greater number of pre-term deliveries, obestricians say.