Study Finds Bed Sharing Among Parents & Infants on the Rise

Monday, January 13, 2003

Bed sharing-the practice of letting babies sleep in an adult bed with a parent or caregiver-is increasing in the United States, according to a study by researchers at the National Institute of Child Health and Human Development (NICHD).

Bed sharing, although common in many cultures, is controversial in this country. While proponents claim benefits, such as more and longer periods of breastfeeding, there are hidden hazards in letting babies sleep on adult beds, including falls, suffocation, and getting trapped between the bed and a wall, the head board, or foot board.

The study appears in the January 2003 Archives of Pediatrics and Adolescent Medicine.

The National Infant Sleep Position Study (NISP), funded by NICHD, the National Institute on Deafness and Other Communication Disorders (NIDCD), and Boston University, shows that the proportion of infants usually sharing an adult bed at night increased from 5.5 percent to 12.8 percent between 1993 and 2000. Nearly 50 percent of infants in the study spent at least some time in the past two weeks sleeping on an adult bed at night. In addition, African American infants were four times more likely to bed share as white infants, and Asian/other infants were almost three times more likely to bed share than white infants.

A second study, funded by NICHD and the National Institutes of Health (NIH) Office of Research on Minority Health, and appearing in the same journal, found almost 50 percent of mothers in a predominantly low-income, inner city population reported their infant usually shared a bed with a parent or other adult during the infant's first year of life.

Both studies suggest that bed sharing appears to be widespread and strongly influenced by cultural factors.

"Bed sharing appears to be growing in popularity, but a lot remains unknown about the practice," said Duane Alexander, M.D., Director of the NICHD. "These studies provide valuable information that will enable organizations to tailor messages about safe sleeping practices to those who need them most."

The NISP study, a telephone survey of 8,453 nighttime caregivers conducted between 1993 and 2000 throughout the 48 contiguous United States, found that the number of infants usually sharing an adult bed at night increased from 5.5 percent to 12.8 percent. According to first author Marian Willinger, Ph.D., of the Pregnancy and Perinatology Branch, NICHD, infants of mothers under 18 years old were twice as likely as other infants to share a bed with a parent or caregiver. Low household income also increased the likelihood of bed sharing by 50 percent.

The second study, which was conducted in Washington D.C. between 1995 and 1996, interviewed 369 mothers when their infants were between the ages of 3-7 months and again when they were 7-12 months of age. Mothers interviewed in this study were predominantly African American/Non-Hispanic (82 percent) and unmarried (73 percent). Sixty-eight percent reported incomes below the federal poverty level. The study, led by Ruth Brenner, M.D., M.P.H., of the Division of Epidemiology, Statistics, and Prevention Research, NICHD, found that 48 percent of all the infants usually bed shared at 3-7 months. Of those who shared a bed at 3-7 months of age, 75 percent continued to do so at 7-12 months of age. The researchers found that infants were more likely to bed share, at both 3-7 months and at 7-12 months, if their mothers were single or if the family had moved at least once since the birth of the infant.

According to both studies' authors, bed sharing is a controversial and poorly understood practice. Proponents argue that bed sharing contributes to more and longer periods of breastfeeding, and that bed sharing may protect infants from succumbing to Sudden Infant Death Syndrome (SIDS) by increasing infant awakenings, decreasing the time spent in deep sleep, and increasing the mother's awareness of the infant. Opponents to the practice of bed sharing cite the potential hazards of bed sharing or sleeping on an adult bed, sofa, or other non-juvenile furniture. These include suffocation in soft bedding or pillows, entrapment between the bed and wall or involving the bed frame, headboard, or footboard , and bed sharers rolling over onto the infants.

Studies that directly assessed the risk of SIDS associated with bed sharing have not found bed sharing to be protective. Some studies have shown an increased risk for SIDS associated with bed sharing under the following conditions: maternal cigarette smoking, recent maternal alcohol consumption, infant covered by a duvet (similar to a quilt, or comforter), and parental fatigue.

The NISP study is the first to provide an estimate of the proportion of U.S. infants sleeping in a bed with an adult. The study found that nearly 50 percent of the infants in the study spent at least some time in the last two weeks sleeping on an adult bed at night, with 20 percent doing so half the time or more, and 13 percent usually sleeping on an adult bed at night. Because the primary objective of the study was to monitor infant sleep position, the researchers didn't obtain information such as reasons for bed sharing or behaviors associated with bed sharing, such as smoking or alcohol use.

The NISP study also found that bed sharing infants were almost twice as likely to be covered by a quilt or comforter than infants who did not share an adult bed. A quilt or comforter in the bed sharing environment is a potential hazard for SIDS if the baby's face or head gets covered.

More information about bed sharing can be found on the NICHD Back to Sleep campaign home page at http://www.nichd.nih.gov/sids/.

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The NICHD is part of the National Institutes of Health (NIH), the biomedical research arm of the federal government. NIH is part of the U.S. Department of Health and Human Services. The NICHD sponsors research on development, before and after birth; maternal, child, and family health; reproductive biology and population issues; and medical rehabilitation. NICHD publications, as well as information about the Institute, are available from the NICHD Web site, http://www.nichd.nih.gov, or from the NICHD Information Resource Center, 1-800-370-2943; e-mail NICHDInformationResourceCenter@mail.nih.gov.