Risk factors for sudden infant death syndrome: further change in 1992-3

BMJ 1996; 312 doi: (Published 01 June 1996) Cite this as: BMJ 1996;312:1397
  1. Christine M H Hiley, research nursea,
  2. Colin J Morley, lecturera
  1. a Department of Paediatrics, University of Cambridge, Box 116, Addenbrookes Hospital, Cambridge CB2 2QQ
  1. Correspondence to: Dr Morley.
  • Accepted 28 September 1995

We described the change in risk factors for sudden infant death syndrome in three East Anglian health districts in 1992, one year after a campaign to reduce the risk of cot death.1 Fewer babies slept on their fronts, though most new born babies were still put on their sides, not their backs; mothers were more aware of overheating; the incidence of smoking did not change, though more mothers claimed that no one smoked near the baby; and breast feeding rates were similar. We noticed that in the first quarter of 1992 32% of babies slept on their backs compared with 47% in the fourth quarter (P<0.03). This suggested a further change with time, and as the advice was receding into the past we reviewed infant care in December 1993, two years after the campaign, to see if the change continued.

Subjects, methods, and results

The data for 1992 were collected by questionnaires sent to randomly selected mothers of babies born normally at term in Cambridge, Huntingdon, or Bury St Edmunds after the campaign and when their baby was 6 months old. About equal numbers of babies were chosen from each month and hospital, and about 90% of mothers responded. Similar questionnaires were also sent to mothers of 6 month old babies born in December 1993, two years after the television campaign. They were enrolled from the same districts. Of 615 questionnaires posted, 524 (85%) were suitable for analysis.

Mothers in the two datasets had similar maternal age, parity, and education. There was a slight social class difference. Regression analysis showed that these factors did not significantly affect the baby's sleeping position. χ2 Tests and t tests were used to analyse the data. The results are shown in table 1.

Table 1

Data on changes in infant care between 1992 and December 1993

View this table:

Compared with 1992 most babies in 1993 slept on their back; fewer on their side; and few on their front. Sleeping on the back increased with age. Quilts or duvets were used less, although the use of three or more blankets increased. There was less concern about the baby getting too cold and an increased use of wall thermometers. In 1993 more babies stayed longer in their parents' bedroom and more small babies slept in the parental bed. There was still no change in maternal smoking or breast feeding.


The continuing fall in the incidence of cot death2 is strongly associated with increased supine sleeping and changes in infant care still occurring two years after the “reduce the risk” campaign. This suggests that mothers are becoming more confident about the safety of babies sleeping supine. Sleeping position also changed with age. Except for one, the babies who slept on their front had multiparous mothers. The fall in use of duvets and the increase in use of blankets suggests that mothers heeded the advice about duvets: our calculations suggest they were covering their babies appropriately, hence the increased use of blankets. The fact that more babies slept in the parents' bedroom and bed is an important change suggesting that mothers are observing their babies more closely. The lack of change in maternal smoking and breast feeding suggests that mothers are willing to change their baby care but not their own habits. More cot deaths could still be prevented by reducing maternal smoking, continuing to discourage sleeping on the front and possibly encouraging increased vigilance over the baby.

We thank the mothers who enthusiastically filled in the questionnaires and Sheila Levitt for data entry.


  • Funding The Foundation for the Study of Infant deaths and East Anglian Regional Health Authority audit committee; Smith and Nephew Foundation.

  • Conflict of interest None.


  1. 1.
  2. 2.
View Abstract