Newborns were more likely to die while sharing a bed compared with older infants, say doctors who want parents to know about the risks.

Sudden infant death syndrome (SIDS) and other sleep-related causes of infant death have known risk factors but researchers wanted to know if the factors differed by age group.

In a total of 8,207 deaths analyzed, the majority of the infants, 69 per cent, were bed-sharing at the time of death, researchers said in Monday’s issue of the journal Pediatrics.

In bed-sharing, the infant shares the same sleeping surface with another person.

Younger infants were more likely bed-sharing compared with babies aged four months to just under a year (73.8 per cent vs. 58.9 per cent.)

Sleeping infant

Pediatricians say their message against bed-sharing is sometimes a tough sell. (Svetlana Fedoseyeva/Shutterstock)

"The predominant risk factor for younger infants (up to three months of age) is bed-sharing, whereas rolling to prone, with objects in the sleep area, is the predominant risk factor for older infants (four months to 364 days)," Dr. Jeffrey Colvin of Children’s Mercy Hospitals and Clinic in Kansas City, Mo., and his co-authors concluded.

"Parents should be warned about the dangers of bed-sharing, particularly in zero- to three-month-old infants."

They also suggested that parents should be reminded that cribs should be clear of objects so that if an infant rolls, there is no risk of rolling into something that increases the risk of suffocation.

"We always recommend that the baby's sleep environment be clear of blankets and pillows and bumper pads," said study co-author Dr. Rachel Moon, a pediatrician in Washington. "I think that parents may forget that as the baby gets a little older, but it is even more critical as the baby gets older and becomes more mobile."

The Canadian Paediatric Society reaffirmed its recommendations for safe sleep environments for infants and children in February.

"The recommended practice of independent sleeping will likely continue to be the preferred sleeping arrangement for infants in Canada, but a significant proportion of families will still elect to sleep together," the society’s position statement said. "The risk of suffocation and entrapment in adult beds or unsafe cribs will need to be addressed for both practices to achieve any reduction in this devastating adverse event."

Hard subject to broach with parents

Taya Griffin of Toronto shares the bed with her 11-month-old, Mabel, as she did with her older daughter. Griffin believes the close proximity facilitates breastfeeding and peaceful sleep.

"I would say that it's one of the best experiences that I've had as a mom because waking up to this little thing smiling at you every morning right there is incredible," Griffin said.

Dr. Janice Heard of the Canadian Paediatric Society in Calgary talks to parents about the risks.

"It is a difficult question to have to broach with parents because there are so many cultural understandings and beliefs about breastfeeding and beliefs about bed-sharing," Heard said.

"People will say, 'this has been done for thousands of years all over the world.' But we do have the evidence to show that those babies do have a higher incidence of death and so it is hard to understand that people would take that risk."

The Canadian society noted that evidence suggests bed-sharing with an adult who is extremely fatigued or impaired by alcohol or drugs (legal or illegal) that impair arousal can be hazardous to an infant.

Canadian coroners have also warned about the hazards.