Sharing sleep space with infants in a "family bed" makes for controversy that just won't quit.
But some experts hope gathering facts about otherwise healthy infants - most younger than 5 months old - who die unexpectedly while sleeping with an adult or sibling, or in an unsafe sleep environment, or from Sudden Infant Death Syndrome will finally put the debate to rest.
And encourage parents to focus on providing a safe sleeping environment for their babies.
In New Hampshire, 81 such infants died in their sleep from 2006 through 2012, according to preliminary data collected by the state Office of Chief Medical Examiner.
"This type of death is so easily preventable," said Dr. Thomas Andrew, the state's chief medical examiner, referring to co-sleeping and unsafe sleep environment deaths.
About half of the 81 deaths involved bed-sharing. None were considered suspicious, Andrew said.
"Of the infants sleeping alone, many listed risks such as fluffy bedding, soft mattresses, overbundling, or other unsafe sleep environments," Andrew said.
Among the possible dangers are obstructing the infant's mouth and nose, which can lead to asphyxia, or rebreathing exhaled carbon dioxide, which can also induce death, Andrew said.
Placing infants on their stomachs to sleep is also a high-risk practice. Sleeping with infants on couches and chairs are considered risks as well, he said.
Adults who smoke, drink, use drugs or who are obese also increase the risk of infant death if they co-sleep with infants, he said.
Proponents insist bed-sharing is natural and if done safely, promotes infant health and family bonding. But medical examiners such as Dr. Andrew, and the American Academy of Pediatrics, say don't do it because it can lead to unnecessary deaths.
Andrew thinks it will take a concerted multi-pronged campaign to change co-sleeping behaviors.
There are about 4,200 sudden unexpected infant deaths per year in the United States. Half are caused by Sudden Infant Death Syndrome, according to the CDC.
The cause of 39 of the 81 unexpected infant deaths in New Hampshire was listed as SIDS, although some were not what Andrew would consider "classic SIDS cases" because they involved other risk factors such as fluffy bedding or babies sleeping on their stomachs.
Nine deaths involved accidents during sleep, such as an adult rolling over on an infant, called accidental overlay, or the infant becoming wedged in a couch after slipping off a sleeping parent's chest.
An additional 33 deaths were listed as undetermined.
"Of every 10 or 12 such deaths, about two will be classic SIDS cases," Andrew said. "Six or seven will be co-sleeping and three or four will likely involve unsafe sleep positions or bedding."
The CDC defines SIDS as the sudden death of an infant younger than 1 year old that cannot be explained after a thorough investigation is conducted.
"If the death has been certified as undetermined, chances are exceedingly great the issue there was an unsafe sleep environment," Andrew said. "I would say there's a slight majority that were co-sleeping, and the remainder involved things like overbundling, fluffy bedding" and other unsafe sleep environments.
Infants don't have the gross motor skills to rescue themselves, roll over or turn their heads when stuck in dangerous positions. "A 3- or 4-week-old has minimal muscle control," Andrew said.
Andrew's office obtained a CDC grant along with nine other states to obtain detailed information about such deaths to find ways to prevent them in the future. And to come up uniform definitions and consistent reporting systems.
The word needs to reach new parents, especially those who rely on older family members who slept with their infants without a problem, he said.
"More and more young parents are subscribing to the family bed and skin-to-skin school of thought," Andrew said.
James J. McKenna, Ph.d, is an advocate of informed choice on bed-sharing.
The director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame cautions parents to make sure the mother is breast-feeding and the sleep environment is safe if they bed-share. Adults who use drugs or alcohol shouldn't bed-share, he said. Mothers who smoke also shouldn't sleep with their infants, McKenna said.
"Sleeping with human infants is more than a nice social idea," McKenna said. "It becomes the baby's physiology" and regulates breathing, heart rate and body temperature, he said.
"Babies love to sleep next to moms and dads."
McKenna is seeing a surge in mothers who work and breast feed. At night, they want to be close to their infants by sharing sleep space, he said.
When otherwise healthy babies die in their sleep, officials often don't explain the whole picture, he said.
"What is true overwhelmingly is when babies die in beds with parents, there is not only one independent risk factor but several. Maybe the baby was prone, the mother was not breast-feeding and the mom smoked," McKenna said.
Bed-sharing is only one way for parents and babies to be close at bedtime, he said,
Most experts agree that co-sleeping in the same room on separate surfaces such as cribs and portable cribs is beneficial and can be done safely, McKenna said.
More new parents are bed-sharing, though, he said. A recent survey in California showed 80 percent of new parents had slept with or were sleeping with their infants, he said.
"I am amazed. My website gets 10,000 to 20,000 hits per month, and most go to the safety page."
McKenna is critical of the campaigns to end bed-sharing.
"We need to know how to do it safely," he said.
Bethlehem midwife Natanya Champney believes bed-sharing is becoming more common, something she practices, as well, but doesn't universally endorse.
"I don't think it is right for everyone," Champney said.
For many new parents, a product called a co-sleeper can be a good compromise, she said.
"Its like a crib that attaches on the bed," Champney said.
Dr. Robert Darnall, who teaches pediatrics and physiology at the Geisel School of Medicine at Dartmouth College, also sits on the American Academy of Pediatrics task force on SIDS.
"The basic thing we have to do is eliminate anything in the sleep space that could possibly be asphyxiating for one reason or another," Darnall said.
Babies should sleep alone on a firm mattress with no soft blankets, no stuffed toys, no crib bumpers, he said.
"Basically a bare crib with the infant sleeping on its back," Darnall said.
"Sharing a room with parents is protecting the infant," Darnall said. "Having the baby in bed with parents increases risk of sudden death."
Another factor that complicates the risk picture is the fact that some infants have brain abnormalities that could undermine their ability to control breathing and arousal mechanisms.
"The evidence suggests there is no protection provided from infants sleeping with a parent," Darnall said. And lots showing it is unsafe.
"Why take the chance?" Darnall asked.
"We all should be conscious of safe sleep because it can save lives."email@example.com