Cot death recurrence ‘overestimated’

Recurrence of sudden infant death syndrome (SIDS) has been “overestimated”, a report claims today.

Each year in England and Wales there are about 350 sudden and unexpected deaths in infancy and roughly two-thirds of these are designated as SIDS, often referred to as cot death, if thought to be from natural causes.

A review published online today in the Archives of Disease in Childhood journal argues that studies which have tried to quantify how many cases of SIDS reoccur in families have overestimated the number.

UK researchers reviewed eight population-based studies published in English since 1970 which had reported relative risks of recurrence of SIDS ranging from 1.7 to 10.1 compared with the general population or controls.

They looked at three main issues: whether all relevant cases of SIDS had been identified reliably; if they had been matched with controls; and that appropriate investigations had been carried out to ensure the SID diagnosis was accurate.

“We found that all the studies failed to meet these criteria, and we think that their flaws would have resulted mainly in overestimation of recurrence risk,” the researchers write.

“Although an increase in risk is probable on theoretical grounds, this risk cannot be quantified from the available evidence.”

They conclude that professionals should be cautious in issuing the chances of recurrence and that parents who have lost a baby to SIDS “can, with the exception of particularly vulnerable families, be reassured that the risk of recurrence is small”.