Cause of Sudden Infant Death Syndrome May Be Biological

Scientists have uncovered a new clue as to why some infants suddenly die in their sleep, a puzzling phenomenon that kills, on average 27,700 babies, a year and is still the leading cause of death between 28 to 360 days of age worldwide.

Starting in the 1990s, the United States launched a campaign encouraging safe sleeping environments for newborns to prevent sudden infant death syndrome (SIDS). The American Academy of Pediatrics still recommends that parents put their babies to sleep on their backs. While the national rate of SIDS dropped by 45%, deaths still occur, with 103 seemingly healthy babies dying out of every 100,000 a year.

Now, researchers at the San Diego Medical Examiner's Office looked at brain tissue related to 70 infant deaths between 2004 and 2011. They found that a receptor called serotonin 2A/C was altered in the brain stem compared to babies who died of other causes. The serotonin 2A/C plays a role in waking up a baby in order to gasp for air. When it isn't activated, the baby won't take a breath for oxygen response.

Although researchers aren't sure this is the sole reason for SIDS, this is a hopeful discovery for parents around the globe. It also means that infants may not be accidentally strangled to death in their cribs, but it could be an underlying biological factor. Another recent study looked at blood samples from babies who died of SIDS and found decreased activity in an enzyme called butyrylcholinesterase. Another study pointed to genetics being a large factor in SIDS.

The researchers believe that when a child succumbs to SIDS, it is due to three components. First, a newborn is in a critical cardiorespiratory period, second, the child should not sleep face down or share a bed, and lastly, the child has a biological difference that makes them more vulnerable.

Researchers are putting together the pieces and attempting to see how they all fit together, possibly influencing one another along the way. The goal for researchers is to figure out how this unfortunate and unexpected death can be measured and prevented.

What are safe sleep practices to prevent SIDS?

According to the Safe to Sleep campaign led by the NIH, evidence-based methods to reduce a baby's risk of SIDS include:

• Position an infant on their back for naps and nighttime sleep.
• Use firm, flat, and level sleep surfaces covered only by a fitted sheet.
• Breastfeed the baby, if possible.
• Share a room with the baby for the first six months, but make sure they are in their own sleep space.
• Do not place toys or other items in the baby's sleeping space.
• Ensure the infant does not get too hot, and keep covers away from the baby's face.
• Allow ample tummy time when the baby is awake and being watched by an adult.

The NIH also notes that it's best to avoid using products, devices, or monitors that claim to prevent SIDS. In addition, parents should refrain from smoking or vaping around the baby and during pregnancy and remain drug and alcohol-free when caring for the infant.