May 25, 2023

New Clues Emerge About Possible Factors Behind Sudden Infant Death Syndrome

Article published by NBC

A new study finds that some infants who die of SIDS have abnormalities in a particular brain receptor that may be involved in helping them gasp for air.

Sudden infant death syndrome, the unforeseen and unexplained death of a baby younger than one year old, is by definition a mystery. But researchers are getting closer to understanding some of the risk factors and mechanisms that contribute to SIDS.

The prevailing theory points to three possible factors: First, the infant is at a critical stage of development during the first year of life. Second, the baby is exposed to a stressor, such as sleeping face down, which can lower the amount of oxygen in their blood while raising the level of carbon dioxide. And third, the infant has an underlying abnormality that makes it harder to survive that traumatic event.

A study published Thursday in the Journal of Neuropathology & Experimental Neurology points to one such abnormality.

Researchers from Boston Children’s Hospital and Rady Children’s Hospital in San Diego found that a particular brain receptor likely involved in helping babies gasp for air was altered in some infants who died of SIDS. The receptor in question is part of the serotonin system, which plays an important role in regulating involuntary body functions like heart rate, breathing and blood pressure.

SIDS usually happens during an infant’s sleep, and though it’s rare, it’s the leading cause of death among babies between one month and one year old in the U.S. The Centers for Disease Control and Prevention attributed nearly 1,400 infant deaths to SIDS in 2020.

To better understand the condition, the researchers behind the new study examined brain tissue from 58 infants who died of SIDS between 2004 and 2011, then compared those samples to the brain tissue of 12 infants who died of other causes, such as pneumonia or heart disease. The results showed that the babies who’d died of SIDS were more likely to have an altered version of the serotonin-related brain receptor than the control cases.