Hamburg, Germany  - Head coverings and other factors such as sleeping away from home, could be linked to Sudden Infant Death Syndrome (SIDS), according to new findings by German researchers.

Other factors included sleeping in a different room of the house or parents placing an infant in a prone position when the baby is accustomed to sleeping on its back, according to the team of German scientists from the University of Muenster headed by Dr. Mechtild M. Vennemann.

Most startling of all was the link between SIDS and babies whose heads had been covered. In the German study of 333 cot deaths, 28 per cent of SIDS deaths involved babies whose heads had been covered. In a New Zealand study of 393 deaths, the ratio of head-covered babies was 15 per cent.

"In both studies, being found with head covering was associated with being very sweaty when found," Dr. Vennemann wrote. "Both the position in which the child was placed to sleep and the position in which the child was found were not associated with head covering."

"The finding that sudden infant death syndrome cases in which infants were found with their heads covered were often very sweaty suggests that head covering ... preceded the death and may have been causally related to the death," she added. "Infants who were found with their head covered were older, which probably reflects motor development."

In related findings from the German study of 393 baby deaths over a three-year period, the researchers found that being placed in a prone position was linked to SIDS, especially in babies unaccustomed to sleeping on their stomachs.

"Although only 4.1 per cent of the infants were placed prone to sleep, those infants were at a high risk of sudden infant death syndrome," Dr. Vennemann wrote. "Those who were unaccustomed to sleeping prone were at very high risk, as were those who turned to prone."

Other factors, she added, included "bed sharing (especially for infants younger than 13 weeks); duvets; sleeping prone on a sheepskin; sleeping in the house of a friend or a relative (compared with sleeping in the parental home); and sleeping in the living room (compared with sleeping in the parental bedroom)."

All of these factors "increased the risk for sudden infant death syndrome", she said.

"Pacifier use during the last sleep was associated with a significantly reduced risk of sudden infant death syndrome," her report said.

"This study has identified several novel risk factors for sudden infant death syndrome: an increased risk if the infants sleeps outside the parental home, death in the living room, and the high risk when sleeping prone on a sheepskin," Dr Vennemann said.

"However, because the numbers of cases in these groups are small, additional studies are needed to confirm these findings." (dpa)