A team of Australian researchers has identified a biochemical marker in the blood that could help identify newborns at risk of sudden infant death syndrome. This success paves the way for future interventions to prevent death, they say.

In a study published in eBioMedicine, part of the prestigious medical journal The Lancet, researchers found that infants who died of sudden infant death syndrome had lower levels of the enzyme butyrylcholinesterase (BChE) shortly after of birth. This enzyme plays an important role in the wakefulness pathway in the brain, and low levels can reduce a sleeping baby’s ability to wake up or respond to its environment.

This is the first evidence that “children who die of SIDS are different at birth,” the study’s lead author Dr. Carmel Harrington of Westmead Children’s Hospital in Australia told Reuters.

“A baby that looks healthy when sleeping and not waking up is every parent’s nightmare,” he added.

The Sydney Children’s Hospital Network in Australia called the opening “a world first”.

However, other experts said last Saturday in the New England Journal of Medicine that researchers are “only halfway through” the goal of fully understanding SIDS and preventing it.