Researchers discuss increase in percentage of infants who share bed with adult or child

In this Research Conversation, Drs. Marian Willinger and Eve Colson explain the findings reported in the NIH news release, Roughly 14 percent of infants share bed with adult or child. Sharing a bed, with an adult or another child, increases an infant's risk of death from sudden infant death syndrome, or SIDS or other sleep-related causes.

NICHD Research Conversations are audio interviews with NICHD scientists and grantees, on the latest NICHD-supported scientific findings. Listen to this Research Conversation at (MP3 - 7 MB).

Ms. Audrey Pernik: Welcome to the National Institutes of Health. I'm Audrey Pernik. Thank you for joining us for today's Research Conversation from the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development. Today, we'll be speaking with Dr. Marian Willinger, special assistant for SIDS at the NICHD, and Dr. Eve Colson of the Yale University School of Medicine. They have published a paper in the Journal of the American Medical Association Pediatrics recently. They found that the percentage of infants who share a bed has doubled over the past decade. Previous research has shown that sharing a bed with an adult or another child puts an infant at increased risk of death from sudden infant death syndrome or other sleep-related causes of unexpected infant death. The study's finding of an increase in bed sharing is cause for concern. However, the study findings also provided a clue as to how to begin reversing this distressing trend. The researchers found that caregivers who were advised by an infant's physician against bed sharing were much less likely to bed share than any other groups in the study. Welcome, Dr. Willinger and Dr. Colson.

First, Dr. Willinger, can you tell us why infants should sleep alone and not with another person?   Dr. Marian Willinger: There have been several studies showing that infants who share a bed with another person are at increased risk of dying from SIDS compared to infants who sleep alone. A recent analysis that combined the studies found that infants who bed share are almost three times more likely to die of SIDS than infants who sleep alone. Also, an adult bed is not a safe place for the baby to sleep. It increases the risk for injury and for death. The baby can suffocate from being overlain by the adult that they are sleeping with, or even another child. They can suffocate from being covered by pillows or blankets, or they can be asphyxiated or strangled through entrapment between the bed and the wall, between the mattress and the bed boards, or they can get injured from falling off the bed. So really, both bed sharing in a bed and being placed to sleep in an adult bed is very risky for the baby.

Ms. Pernik: And in addition to placing infants alone on their backs, what else should caregivers do to provide a safe sleep environment for infants?  

Dr. Willinger: There are several things that caregivers can do to provide a safe sleep environment. Sharing a room with the baby reduces the risk for SIDS by half compared with babies sleeping in their own room. The American Academy of Pediatrics recommends that the baby's crib, bassinet, or play yard be placed in the parent's bedroom close to the parent's bed. Also, this will facilitate bonding and breastfeeding while eliminating the hazard of sleeping in an adult bed. The second thing they can do is to keep soft bedding out of the baby's bed. Therefore, no quilts, comforters, pillows or pillow-like toys, bumpers, loose blankets or sheets should be in the sleep environment. If covering is needed infant sleep clothing like blanket sleepers can be used so there is no risk of the baby's head getting covered by loose bedding. Also, cribs, bassinets, portable cribs, or play yards should meet safety standards, and only those mattresses designed for the specific product should be used. Fitted sheets that fit tightly should be used, and blankets, pillows, quilts, or sheepskin should never be placed under the baby. These are all ways to make the baby's sleep environment safe.

Ms. Pernik: And Dr. Willinger, could you tell us about how you conducted the study?

Dr. Willinger: Telephone surveys were conducted each year between 1992 and 2010. They were completed with the nighttime caregivers in households with a baby 7 months or younger. The commercially available list of telephone numbers we used to select the sample covered the 48 states in the continental United States and was based on publicly available sources such as birth records and infant photography and feeding company lists. The survey obtained information on infant sleeping arrangements and other care practices and on sources and content on recommendations regarding infant care practices. More than 80 percent of the nighttime caregivers who responded to the telephone survey were mothers.

Ms. Pernik: And Dr. Colson, what were your findings?

Dr. Eve Colson: There were four key findings that I'd like to emphasize. First, as you mentioned, there's been an increase in the number of infants who are bed sharing. In 1993, for example, 6.5 percent of the participants reported that the baby usually bed shared. And that more than doubled to 13.5 percent in 2010. Second, for all years, white infants were less often reported to be sharing a bed than were black and Hispanic infants. Third, the racial gap for bed sharing widened in the most recent years, from 2001 to 2010. More Hispanic and black participants reported that the babies where bed sharing. There was no significant change for white infants. This finding is really worrisome, especially because we know that black infants are among those of the highest risk of dying from SIDS. And finally, for many participants, a doctor did not even talk to them about bed sharing. But doctors' advice really does matter. What we found was that if the caregiver said the doctor's attitude was against bed sharing, the infant was less likely to be bed sharing. If the participant perceived that the doctor was neutral about bed sharing—in other words, he or she said it really didn't matter what the family decided to do related to bed sharing—the infant was more likely to bed share than if their doctor did not talk to them at all. The take-home message is: It is important for doctors to let families know about the recommendation, and they need to tell families not to bed share.

Ms. Pernik: And what do you think may be behind the increase in bed sharing?

Dr. Colson: It is hard to know exactly what is behind the increase in bed sharing from this study because it was not really designed to answer this question. While rates have risen throughout 1993 to 2010, the factors that are contributing to that increase may have changed over time. When we compared the factors that influenced bed sharing in 1993—between 1993 to 2000 versus 2001 to 2010—in the later time period, maternal education level and the gestational age of the baby became significant factors, when it wasn't in the earlier time period. Also the racial disparity in bed sharing has widened since 2001, and it is important for us to investigate why these are occurring.

Ms. Pernik: Dr. Colson, can you tell us more about the potential role for physicians in reducing the trend toward bed sharing?

Dr. Colson: What our study shows is that the role for the physician is that they should understand that their opinion and what they tell families is important. If we consistently give advice that infants should not bed share, it is likely that fewer infants will bed share. That may decrease the number of infant deaths due to SIDS or unintentional injuries while sleeping in the adult bed or other unsafe sleep surfaces.

Ms. Pernik: And Dr. Colson, based on these findings, what advice do you have for physicians caring for newborn infants?

Dr. Colson: So I would tell doctors, use every opportunity that you get. You should talk to families about bed sharing, and you should work with your colleagues in health care to make sure that we are all on the same page.

Ms. Pernik: Dr. Willinger, can you sum up the most important things that you think our listeners should remember from this study's findings?

Dr. Willinger: Our listeners should remember that bed sharing is hazardous. Infants who bed share are at increased risk for sudden infant death syndrome, and they're at increased risk for injury and death from just sleeping in an adult bed, which is a hazardous environment. They're at increased risk for suffocation, for overlay, for entrapment, for falling. The other important thing from this study is that we learned that if doctors talk with their patients about bed sharing and provide advice against bed sharing, that parents are less likely to bed share. So doctors have a very important role here in reducing this hazardous practice. And also parents should remember that if their doctor does not offer any recommendations regarding bed sharing and they have questions about it, that they should initiate a conversation with their practitioner.

Ms. Pernik: That concludes today's research conversation. Thank you to Dr. Willinger and Dr. Colson for joining us to talk about your research. More information about providing a safe sleep environment for infants is available at


About the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): The NICHD sponsors research on development, before and after birth; maternal, child, and family health; reproductive biology and population issues; and medical rehabilitation. For more information, visit the Institute's website at

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