Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) (also known as crib death or cot death) is the leading cause of death for Canadian infants between 28 days and one year of age.

SIDS refers to the sudden and unexpected death of an apparently healthy infant under one year of age which remains unexplained after all known and possible causes have been ruled out through autopsy, death scene investigation and review of the medical history.

These articles examine current rates and temporal trends in infant mortality attributed to SIDS in Canada and compares Canada's SIDS rate to rates in other developed countries. It also highlights the epidemiology of SIDS, prevention efforts and limitations of the SIDS data.

Assigning SIDS as a cause of death is the responsibility of the local medical examiner. The provincial/territorial vital registrars offices collect, code and submit this information to Statistics Canada.

Unless referenced otherwise, SIDS statistics are taken from the Canadian Vital Statistics System, Statistics Canada.

Definitions of Key Terms

The infant mortality rate is the number of infant deaths per 1,000 live births. The neonatal period extends from birth through day 27. The post-neonatal period extends from day 28 through day 364. SIDS Rates In 1996, there were 2,051 reported infant deaths in Canada. Of these deaths, 168 (8.2%) were attributed to SIDS.

Since 1980, the overall rate of SIDS deaths in Canada has been steadily declining from 1.2 per 1,000 live births in 1980 to 0.5 per 1,000 live births in 1996 SIDS Rates Canada, 1980-1996 Source: Statistics Canada. Mortality: summary list of causes, 1980-1995. Statistics Canada. Canadian Vital Statistics System, 1996.

In 1996, SIDS was the leading cause of post-neonatal mortality in Canada, accounting for 26% of all post-neonatal deaths. Birth defects, the second leading cause, accounted for 23% of post-neonatal deaths. As both the post-neonatal mortality rate and the SIDS rate have declined, the proportion of post-neonatal mortality attributed to SIDS has remained steady since 1980

In comparison to other developed countries, the 1996 Canadian SIDS rate of 0.5 per 1,000 live births is lower than the rate in Australia (0.9 per 1,000 live births), USA (0.8 per 1,000 live births) and England/Wales (0.7 per 1,000 live births). However, the Canadian rate remains higher than rates reported in Japan (0.4 per 1,000 live births) and the Netherlands (0.3 per 1,000 live births)

Prevention of SIDS

To date there is no known definitive cause of Sudden Infant Death Syndrome (SIDS). What is known is that male infants are at a slightly higher risk than females and there is a higher rate of incidence between 2 to 4 months. Additionally there is an increase with infants that are from a "lower socio-economic" household.

However, there are precautions that can be taken to minimize the chance of SIDS occurring:

• Infants should sleep on their backs (supine) rather than their stomachs (prone). While most of us were all raised sleeping on our stomachs and are alive to tell the tale since the concept of supine sleeping came about the incidence of SIDS has been reduced. There is a slightly higher risk of SIDS but significant nonetheless if your infant sleeps on his or her side. Therefore, putting infants on their backs to sleep is the most practical choice (unless otherwise instructed by your family pediatrician due to certain illnesses).

• Habits are very hard to break. However, there is an increased occurrence of SIDS when the mother smokes during her pregnancy. Consult with your physician/OB GYN to see if there is help for you to stop smoking while you are pregnant.

• Infants that are around tobacco smoke are also at an increased risk. If you are unable to quit smoking try and keep it to the outside of your home and keep your automobile comfortably ventilated if you smoke in your car.

• Keep an eye on your infant's blankets. If the head is accidentally covered the risk increases.

• Overheating is yet another SIDS risk factor. Infants are not able to kick off their blankets as an adult would if they were too hot. Therefore, avoid the use of quilts and duvets that would be too heavy and hot.

• Pillows, crib bumpers and soft stuffed toys are all suffocation risks to a small infant.

• There is some research that suggests that there is an increased incidence of SIDS when the parent(s) bring their babies to bed with them. This is higher still if the parents are smokers.

There is constant research going on to discover a cure for SIDS. Thanks to public awareness campaigns there is a significant decline in the number of SIDS deaths as parents and caregivers implement the above mentioned preventions.

For more information, or to be added to CPSS's mailing list, please contact:

Reproductive Health Division Bureau of Reproductive and Child Health
HPB Building, Tunney's Pasture,
A.L. 0701D
Ottawa, Ontario
K1A 0L2
Tel. (613) 941-2395
Fax (613) 941-9927
CPSS e-mail: CPSS@hc-sc.gc.ca
Or visit their website at:
www.hc-sc.gc.ca/hpb/lcdc/brch/reprod.html

The Sudden Infant Death Syndrome and Prevention of SIDS articles were adapted from the fact sheet prepared by Fay McLaughlin, I.D. Rusen and Susie Dzakpasu for the purposes of this website. References:

1. Statistics Canada. Canadian Vital Statistics System, 1996.

2. Injury Prevention Committee, Canadian Paediatric Society. Reducing the risk of sudden infant death. Journal of Paediatrics and Child Health 1996;1(1):63-7.

3. Statistics Canada. Mortality - summary list of causes, 1995. Catalogue 84-209-XPB.

4. Dwyer T, Ponsonby AL. Sudden infant death syndrome - insights from epidemiological research. J Epidemiol Community Health 1992; 46:98-102.

5. Henderson-Smart DJ, Ponsonby AL, Murphy E. Reducing the risk of sudden infant death syndrome: A review of the scientific literature. J Paediatr Child Health 1998; 34:213-19.

6. Fleming PJ, Blair PS, Bacon C, et al. Environment of infants during sleep and risk of the Sudden Infant Death Syndrome: results of 1993-95 case-control study for confidential inquiry into stillbirths and deaths in infancy. Br Med J 1996; 313:191-95.

7. Blair PS, Fleming PJ, Bensley D, et al. Smoking and the Sudden Infant Death Syndrome: results from 1993-95 case-control study for confidential inquiry into stillbirths and deaths in infancy. Br Med J 1996;313:195-98.

8. Mitchell EA, Taylor BJ, Ford RPK, et al. Four modifiable and other major risk factors for cot death: The New Zealand Study. J Paediatr Child Health 1992; 28 (Suppl 1):S3-8.

9. Ford RPK, Taylor BJ, Mitchell EA, et al. Breastfeeding and the risk of sudden infant death syndrome. Int J Epidemiol 1993;22(5):885-90.

10. Gilbert RE, Wigfield RE, Fleming PJ, Rudd PT. Bottle feeding and the Sudden Infant Death Syndrome. Br Med J 1995; 310:88-90.

11. Joint statement: Reducing the risk of sudden infant death syndrome in Canada. Ottawa, 1999. Catalogue: H39-466/2-1999. 12. Committee on Child Abuse and Neglect, American Academy of Paediatrics. Distinguishing Sudden Infant Death Syndrome from child abuse fatalities. Paediatrics 1994; 94(1): 124-26. (September 1999)

© Minister of Public Works and Government Services Canada, 2000. All rights reserved. This text may be reproduced in whole or in part by any means provided that: physical copies are not sold; access to electronically-stored copies does not require an incremental fee beyond customary subscription fees and costs of connection time; and Health Canada is acknowledged as the copyright holder. To obtain permission to reproduce in whole or in part for purposes of resale or redistribution, contact Health Canada. Translations and modifications are not permitted without the consent of Health Canada.