This article appears in Family magazine February 2018.

Sudden infant death syndrome, or SIDS, affects about 1,600 babies younger than 16 months each year, according to the Centers for Disease Control and Prevention. Now, two new studies are casting light on both a potential cause and a way to reduce the risk.

Breastfeeding halves risk

Breastfeeding an infant for at least two months cuts a baby’s risk of SIDS almost in half, according to an international study published in the journal Pediatrics. Moms don’t even need to breastfeed exclusively to get the benefit.

“These results are very powerful! Our study found that babies who are breastfed for at least two months have a significant reduction in their risk of dying from SIDS,” said researcher Kawai Tanabe of the University of Virginia School of Medicine. “Breastfeeding is beneficial for so many reasons, and this is really an important one.”

Previous studies suggested that breastfeeding was associated with a decreased risk of SIDS, but this study is the first to determine the necessary duration to provide the protection. While any amount of breastfeeding reduces the risk of SIDS, the longer babies are breastfed, the greater the protection, researchers found. Additionally, both partial and exclusive breastfeeding yielded the same benefit.

It is unclear why breastfeeding protects against SIDS, though the researchers cite factors such as immune benefits and effects on infant sleeping patterns as possible mechanisms.

Abnormality linked to SIDS

New research has uncovered a developmental abnormality in babies — especially in premature babies and in boys — that for the first time has been directly linked to cases of sudden infant death syndrome.

Researchers believe this abnormality, in the brain’s control of head and neck movement, breathing, heartbeat and the body’s responses to deprivation of oxygen supply, could be the reason why some babies sleeping on their front are more at risk of SIDS.

“An infant with this abnormality is likely to have impaired respiratory and motor responses to life-threatening challenges during sleep. While they may be otherwise healthy-looking, there is an inability for that child’s brain and body to respond appropriately to an event in which the child is deprived of oxygen in some way,” said Dr. Fiona Bright, research associate in the Adelaide Medical School, University of Adelaide, South Australia. The research was conducted in collaboration with Harvard Medical School and Boston Children’s Hospital.

Multiple studies have pointed to a subset of babies stricken with SIDS that are not entirely “normal” before death.

“We’ve known for many years that babies sleeping face-down places them at greater risk of SIDS — now we have a much better understanding as to why,” said study supervisor Professor Roger Byard, professor of pathology at the University of Adelaide.

Researchers hope more study will lead to screening techniques or biomarkers to identify infants who may be at risk of SIDS.