Can the fall in Avon's sudden infant death rate be explained by changes in sleeping position?
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R E Wigfield1, P J Fleming, P J Berry
1Institute of Child Health, Bristol.
Insights
Changing infant sleeping position from prone to supine or side sleeping significantly reduced sudden infant death syndrome (SIDS) mortality. The study recommends the supine position as the safest for babies to prevent SIDS.
Area of Science:
- Pediatrics
- Public Health
- Epidemiology
Background:
- Sudden Infant Death Syndrome (SIDS) remains a significant concern in infant mortality.
- Infant sleeping practices, particularly sleeping position, have been investigated for their role in SIDS.
- Previous studies indicated a potential association between prone sleeping and increased SIDS risk.
Purpose of the Study:
- To investigate the impact of shifts in infant sleeping position practices on SIDS mortality rates.
- To evaluate the effectiveness of public health recommendations regarding infant sleep positioning.
Main Methods:
- A population-based case-control study was conducted in the County of Avon.
- Data on infant sleeping position were collected through home visits for infants who died suddenly and unexpectedly and for control infants.
- The study design was comparable to earlier research in the same population to assess changes over time.
Main Results:
- The prevalence of prone sleeping decreased significantly from 58% in 1987-9 to 28% in 1990-1.
- This reduction in prone sleeping was associated with a projected decrease in SIDS incidence.
- Actual SIDS mortality rates fell from 3.5 per 1000 live births to 1.7 per 1000 live births.
Conclusions:
- The observed decline in SIDS mortality is largely attributable to the reduction in infants sleeping in the prone position.
- Both side and supine sleeping positions offer protection against SIDS.
- The supine sleeping position is recommended as the safest option for infants due to its stability and protective effect.
Objective:
To examine the impact of changing practice with regard to infant sleeping position on mortality from the sudden infant death syndrome.
Design:
A population based study of all infants dying suddenly and unexpectedly during February 1990 to July 1991, and two groups of controls; one comprising every 125th baby born to Avon residents and the other comprising pairs of infants matched to each index case for age, neighbourhood, and date of study. Information about sleeping position was collected at home visits soon after the index baby's death or, for the population based controls, on several occasions in the first six months of life. The design was comparable to that of an earlier study of the same population.
Setting:
County of Avon.
Subjects:
35 infants who died suddenly and unexpectedly (32 of the sudden infant death syndrome), 70 matched controls, and 152 population based controls.
Results:
The prevalence of prone sleeping in the matched controls was much lower than that found in an earlier study in Avon (28% (18/64) 1990-1 v 58% (76/131) 1987-9; p less than 0.001) and was comparable with the prevalence in population based controls (29%). This would be expected to lead to a reduction in the incidence of the sudden infant death syndrome to 2.0/1000 live births (95% confidence interval 1.8/1000 to 2.5/1000). The actual mortality fell from 3.5/1000 in 1987-9 to 1.7/1000.
Conclusion:
The fall in mortality can be almost entirely accounted for by the reduction in prone sleeping, suggesting a causal relation exists between them. Side and supine positions confer protection but the side position is unstable and the infant may roll prone. We therefore recommend supine as the safest sleeping position for babies.
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