Why is the cot death rate higher for twins than for singleton babies?
First, if the twins are not the mother’s first pregnancy, often the mother already has a cot mattress. Secondly, many twins sleep in the same cot when they are very young babies, but at some point while still within the cot death risk age are separated so that they are sleeping in separate cots. Both of these situations require a second mattress to be obtained. As a consequence, it often occurs that one twin in a family sleeps on a previously used mattress, while the other twin sleeps on a new mattress. This has the result that the cot death rate among twins is significantly higher than among singleton babies; also it is statistically much more likely that one twin will die of cot death than the other. The twin sleeping on the re-used mattress is at around double the cot death risk of the twin sleeping on the new mattress.
