Whilst we don’t know what causes cot death, there are certain factors which are known to increase the risks; and certain babies may be more vulnerable to cot death than others.

However, you should remember that cot death is relatively rare and by following the safe sleeping advice, you will be doing everything you possibly can to reduce the chances of it happening.

Smoking

There is significant evidence to demonstrate that smoking during pregnancy and after the baby is born can increase the risks of cot death, resulting in a seven-fold increase in risk when the mother smokes over 20 cigarettes per day.

Smoking by parents and other household members after the baby is born also increases the risk. The infants of drug-abusing mothers are also more vulnerable to cot death.

Age

A small number of cot deaths occur in the first month of life. The incidence rapidly rises, after that, reaching a peak in the second and third months. The majority of cot deaths occur in the first six months and only about 5% in babies aged 9-12 months. A very small number of cot deaths, 3-4%, take place in the second or third year of life.

Gender

There is a clear gender difference in cot death with boys seemingly more at risk than girls; with a male to female ratio of approximately 2:1.

Seasonal Incidence

Cot death is more common in winter than in summer – approximately 60% of deaths occur in winter/spring compared with 40% in summer/autumn.

Birth Order

Second and later born infants in a family are at greater risk than first born.

Maternal Age

Young mothers (under 20 years old) are more likely to lose a baby/child to cot death than older mothers. The average age of cot death mothers is two years younger than the general maternal population.

Obstetric Factors

Preterm (born before 37 weeks) and low birth weight babies (weighing less than 2.5kg or 5lbs 8oz) are more likely to die from cot death than full term infants. Twins are also more vulnerable.

Socio-Economic Factors

Cot death occurs in all social groups, but is more common in areas of social deprivation.

Infant Care Practices

• It is well documented that placing a baby to sleep on its back is the safest position for a baby to sleep. Unless you have been advised by your baby’s doctor to place your baby to sleep in another position, you should always place your baby to sleep on its back.
• Sharing a sleep surface (such as a bed, sofa, chair, bean-bag) with your baby can increase the risks of cot death. These risks are further increased if your baby was premature; was a low birth weight; if either parent smokes (even if they only smoke outside); if the parents have consumed any alcohol or taken drugs or medication (including Methadone or illegal drugs) that could make them more sleepy. Almost 70% of all cot deaths in Scotland have happened when the baby was sharing a sleep surface with one or more adults.
• Overheating may make a baby more vulnerable and several studies have shown that babies whose heads are accidentally covered with bedding are at greater risk.