The New England Journal of Medicine says scientists in Italy have identified that babies with a longer interval between contractions in different parts of their hearts could have a 41-fold increased risk of sudden infant death syndrome (SIDS).

This would make it highter than other traditional risk factors such as putting babies to sleep face down in their cots.

Abnormal heartbeat

The scientists, from the University of Pavia, studied more than 34,000 newborn babies over 19 years. Twenty-four died from SIDS and the researchers found that almost half had the abnormal heart rhythm.

SIDS is the main cause of death among apparently healthy babies in their first year of life, although it is relatively rare. It kills only 0.05 to 0.2% of newborn babies a year.

Electrocardiagram

The abnormal heart rhythm can be identified on an electrocardiagram, but the researchers have warned against introducing routine screening for babies.

It may be too early for routine screening

They say many children with the abnormal heartbeat do not die of SIDS so other factors must be responsible, and require extra research.

Unless children at risk are more clearly identified, the benefits of treating the abnormality could be outweighed by the dangers.