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Babies sleeping with parents: case-control study of factors influencing the risk of the sudden infant death syndromeCommentary: Cot death—the story so far

BMJ 1999; 319 doi: http://dx.doi.org/10.1136/bmj.319.7223.1457 (Published 04 December 1999) Cite this as: BMJ 1999;319:1457

Abstract

Objective: To investigate the risks of the sudden infant death syndrome and factors that may contribute to unsafe sleeping environments.

Design: Three year, population based case-control study. Parental interviews were conducted for each sudden infant death and for four controls matched for age, locality, and time of sleep.

Setting: Five regions in England with a total population of over 17 million people.

Subjects: 325 babies who died and 1300 control infants.

Results: In the multivariate analysis infants who shared their parents' bed and were then put back in their own cot had no increased risk (odds ratio 0.67; 95% confidence interval 0.22 to 2.00). There was an increased risk for infants who shared the bed for the whole sleep or were taken to and found in the parental bed (9.78; 4.02 to 23.83), infants who slept in a separate room from their parents (10.49; 4.26 to 25.81), and infants who shared a sofa (48.99; 5.04 to 475.60) The risk associated with being found in the parental bed was not significant for older infants (>14 weeks) or for infants of parents who did not smoke and became non-significant after adjustment for recent maternal alcohol consumption (>2 units), use of duvets (>4 togs), parental tiredness (infant slept ≤4 hours for longest sleep in previous 24 hours), and overcrowded housing conditions (>2 people per room of the house).

Conclusions: There are certain circumstances when bed sharing should be avoided, particularly for infants under four months old. Parents sleeping on a sofa with infants should always be avoided. There is no evidence that bed sharing is hazardous for infants of parents who do not smoke.

Key messsages

  • Cosleeping with an infant on a sofa was associated with a particularly high risk of sudden infant death syndrome

  • Sharing a room with the parents was associated with a lower risk

  • There was no increased risk associated with bed sharing when the infant was placed back in his or her cot

  • Among parents who do not smoke or infants older than 14 weeks there was no association between infants being found in the parental bed and an increased risk of sudden infant death syndrome

  • The risk linked with bed sharing among younger infants seems to be associated with recent parental consumption of alcohol, overcrowded housing conditions, extreme parental tiredness, and the infant being under a duvet

Footnotes

    • Accepted 24 August 1999

    Babies sleeping with parents: case-control study of factors influencing the risk of the sudden infant death syndrome

    1. Peter S Blair, medical statistician (p.s.blair{at}bris.ac.uk)a,
    2. Peter J Fleming, professor of infant health and developmental physiologya,
    3. Iain J Smith, senior lecturer in health research and honorary consultant in child healthb,
    4. Martin Ward Platt, consultant paediatrician and senior lecturer in child healthc,
    5. Jeanine Young, research nursea,
    6. Pam Nadin, research health visitora,
    7. P J Berry, professor of paediatric pathologya,
    8. Jean Golding, professor of paediatric and perinatal epidemiology, the CESDI SUDI research groupa
    1. a Institute of Child Health, Royal Hospital for Children, St Michael's Hill, Bristol BS2 8BJ
    2. b Nuffield Institute for Health Services, Leeds LS2 9PL
    3. c Newcastle Neonatal Service, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP
    4. Department of Paediatrics, Faculty of Medicine and Health Sciences, University of Auckland, Postbag 92019, Auckland, New Zealand
    1. Correspondence to: P Blair
    • Accepted 24 August 1999

    Abstract

    Objective: To investigate the risks of the sudden infant death syndrome and factors that may contribute to unsafe sleeping environments.

    Design: Three year, population based case-control study. Parental interviews were conducted for each sudden infant death and for four controls matched for age, locality, and time of sleep.

    Setting: Five regions in England with a total population of over 17 million people.

    Subjects: 325 babies who died and 1300 control infants.

    Results: In the multivariate analysis infants who shared their parents' bed and were then put back in their own cot had no increased risk (odds ratio 0.67; 95% confidence interval 0.22 to 2.00). There was an increased risk for infants who shared the bed for the whole sleep or were taken to and found in the parental bed (9.78; 4.02 to 23.83), infants who slept in a separate room from their parents (10.49; 4.26 to 25.81), and infants who shared a sofa (48.99; 5.04 to 475.60) The risk associated with being found in the parental bed was not significant for older infants (>14 weeks) or for infants of parents who did not smoke and became non-significant after adjustment for recent maternal alcohol consumption (>2 units), use of duvets (>4 togs), parental tiredness (infant slept ≤4 hours for longest sleep in previous 24 hours), and overcrowded housing conditions (>2 people per room of the house).

    Conclusions: There are certain circumstances when bed sharing should be avoided, particularly for infants under four months old. Parents sleeping on a sofa with infants should always be avoided. There is no evidence that bed sharing is hazardous for infants of parents who do not smoke.

    Key messsages

    • Cosleeping with an infant on a sofa was associated with a particularly high risk of sudden infant death syndrome

    • Sharing a room with the parents was associated with a lower risk

    • There was no increased risk associated with bed sharing when the infant was placed back in his or her cot

    • Among parents who do not smoke or infants older than 14 weeks there was no association between infants being found in the parental bed and an increased risk of sudden infant death syndrome

    • The risk linked with bed sharing among younger infants seems to be associated with recent parental consumption of alcohol, overcrowded housing conditions, extreme parental tiredness, and the infant being under a duvet

    Footnotes

    • Funding The National Advisory Body for CESDI and the Foundation for the Study of Infant Deaths.

    • Competing interests None declared.

    • Accepted 24 August 1999

    Commentary: Cot death—the story so far

    1. Ed Mitchell (ed.mitchell{at}auckland.ac.nz), associate professor in paediatrics
    1. a Institute of Child Health, Royal Hospital for Children, St Michael's Hill, Bristol BS2 8BJ
    2. b Nuffield Institute for Health Services, Leeds LS2 9PL
    3. c Newcastle Neonatal Service, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP
    4. Department of Paediatrics, Faculty of Medicine and Health Sciences, University of Auckland, Postbag 92019, Auckland, New Zealand
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