Two Norwegian doctors say they have proved that victims of sudden infant death syndrome, or crib death, die from a lack of oxygen.
The researchers, Torleiv Ole Rognum and Ola Didrik Saugstad, found unusually large amounts of a chemical called hypoxantin in the eye fluid of infants who have died in this way. The body's hypoxantin rises sharply if oxygen is reduced significantly.
Their research, completed a year ago, showed concentrations of the chemical were six times higher in infants who had suffered crib death than in those who died from other known causes.
"This supports one of the many theories about crib death--that it has something to do with respiratory problems--and discounts a number of others," Rognum said.
Their findings were published this month in the U.S. medical journal Pediatrics.
In a separate report, U.S. health officials said that sudden infant death syndrome continues to be a leading cause of premature mortality.