How Co-Sleeping Affects Baby's Breathing

Important warning? Or—as some co-sleeping moms are saying—just another scare tactic? Waking up the debate over the family bed is new co-sleeping research from New Zealand that says babies who share a bed with their parents are more likely to re-breathe air they've already exhaled and experience oxygen level drops overnight, two risk factors for SIDS, the Huffington Post reports.

The study, published in the journal Pediatrics, used infrared video to monitor 40 healthy infants (age 0 to 6 months old) who routinely shared a bed with at least one parent for five or more hours a night. They compared those infants to 40 babies who slept alone in cribs.

Overall, researchers noted, bed-sharing infants experienced more oxygen desaturations—drops in blood oxygen levels—throughout the night. "Such episodes might occur more frequently when infants sleep in a bed with a parent because the environment is warmer," explains Sally Baddock, an associate professor of midwifery at Otago Polytechnic in New Zealand, who worked on the study. Mild episodes of oxygen desaturation are common in healthy infants, but can become dangerous when they are more severe.

Bed-sharing babies also experienced more episodes of carbon dioxide rebreathing, or breathing in the same air that they had let out. As cameras picked up, this was often because loose bedding or parents' clothing ended up covering babies' breathing passageways.

"For example, if your head is under a blanket, you may be breathing the same air in and out over time. This will mean the air will come to contain increasing levels of carbon dioxide and decreasing levels of oxygen," Baddock tells the Huffington Post.

Should this study spell the end of co-sleeping? Medical groups, including the American Academy of Pediatrics, say the message here is clear: sharing a room with your baby is fine, but sharing a bed is just too risky.

Researchers in New Zealand have a more nuanced take. For example, most babies appeared able to cope with rebreathing (by increasing their breathing rates—a way to keep oxygen levels within the normal range), and parents seemed to adapt as well. As researchers found out when they looked at the overnight video footage, many mothers "spontaneously removed bedding during head covering events."

But at the same time, researchers say that co-sleeping is potentially hazardous, particularly for babies who live with a current smoker or whose mother smoked during pregnancy, or obese parents. Parental alertness is also key: Adults who are unresponsive—because of alcohol or drug use, for example—put their infants at particularly high risk for suffocation or entrapment.

"I think the message is a fair one," Dr. James McKenna, head of the Mother-Baby Behavioral Sleep Lab at the University of Notre Dame, tells the Huffington Post. "They argue that it is not enough to simply judge a practice like bed-sharing as being simply 'dangerous' before determining what kind of bed-sharing is involved and who is involved."

The reaction so far from moms?

Co-sleeping mom Kelly Allen of Atlanta, Georgia, sees it as a scare tactic. "Informed parents already know the 'dont's' of co-sleeping. Don't drink alcohol before bed, don't do drugs and co-sleep, don't sleep on a couch with your baby, and keep your baby's sleeping area free of blankets and pillows. It's actually comforting to know that babies could have some kind of built in ability to deal with unforseen problems. I know I do! I wake up all the time to make sure my son is OK."

But another mom, Brenda Tustin, of Baltimore, Maryland, says this study underscores why co-sleeping is not something she wants for her family. "I am able to avoid this issue entirely with one simple thing: a crib. It's clear of any pillows and blankets and my son always sleeps on his back. Why take the risk?"

What do you think? If you co-sleep, does this study change your mind?