An 8 year study of risk factors for SIDS: bed-sharing versus non-bed-sharing

Arch Dis Child. 2006 Apr;91(4):318-23. doi: 10.1136/adc.2005.074674. Epub 2005 Oct 21.


Background: It is unclear if it is safe for babies to bed share with adults. In Ireland 49% of sudden infant death syndrome (SIDS) cases occur when the infant is bed-sharing with an adult.

Objective: To evaluate the effect of bed-sharing during the last sleep period on risk factors for SIDS in Irish infants.

Design: An 8 year (1994-2001) population based case control study of 287 SIDS cases and 831 controls matched for date, place of birth, and sleep period. Odds ratios and 95% confidence intervals were calculated by conditional logistic regression.

Results: The risk associated with bed-sharing was three times greater for infants with low birth weight for gestation (UOR 16.28 v 4.90) and increased fourfold if the combined tog value of clothing and bedding was > or =10 (UOR 9.68 v 2.34). The unadjusted odds ratio for bed-sharing was 13.87 (95% CI 9.58 to 20.09) for infants whose mothers smoked and 2.09 (95% CI 0.98 to 4.39) for non-smokers. Age of death for bed-sharing and sofa-sharing infants (12.8 and 8.3 weeks, respectively) was less than for infants not sharing a sleep surface (21.0 weeks, p<0.001) and fewer bed-sharing cases were found prone (5% v 32%; p = 0.001).

Conclusion: Risk factors for SIDS vary according to the infant's sleeping environment. The increased risk associated with maternal smoking, high tog value of clothing and bedding, and low z scores of weight for gestation at birth is augmented further by bed-sharing. These factors should be taken into account when considering sleeping arrangements for young infants.

MeSH terms

  • Adult
  • Bedding and Linens
  • Beds* / statistics & numerical data
  • Case-Control Studies
  • Clothing
  • Female
  • Humans
  • Infant
  • Infant Care / methods*
  • Ireland / epidemiology
  • Prone Position
  • Risk Factors
  • Sleep
  • Sudden Infant Death / epidemiology
  • Sudden Infant Death / etiology*
  • Tobacco Smoke Pollution / adverse effects


  • Tobacco Smoke Pollution