It\u2019s a tragedy with few answers: Sudden infant death syndrome is the leading cause of death among babies from 1 month to 1 year old in the U.S. <\/p>\n\n\n\n
Affected infants generally appear healthy but die suddenly, often in their sleep, with no obvious explanation. The Centers for Disease Control and Prevention attributed<\/a> nearly 1,400 infant deaths in 2020 to SIDS, as the condition is known \u2014 the latest available data.<\/p>\n\n\n\n Currently, there\u2019s no way to tell whether a baby might develop SIDS. But a new study has found that a particular group of chemicals called metabolites, which are tested for as part of routine newborn screenings, could identify babies with an elevated risk.<\/p>\n\n\n\n The \u201cheel stick\u201d test is mandated for infants in all 50 states and involves collecting a blood sample from a baby\u2019s heel shortly after birth. That is used to screen for genetic disorders like sickle cell disease via certain markers in the blood.<\/p>\n\n\n\n The new study, published Monday<\/a> in the journal JAMA Pediatrics, found that a group of eight metabolites included on the newborn screening panel was associated with SIDS. The metabolites are produced as the body breaks down nutrients.<\/p>\n\n\n\n The results indicated that infants with particular levels of those metabolites in their blood had a higher risk of SIDS \u2014 up to 14 times the odds compared to infants with the lowest risk.<\/p>\n\n\n\n Laura Jelliffe-Pawlowski, one of the study\u2019s authors and a professor at New York University, said the research suggests that \u201cbabies who die unexpectedly are more likely to be metabolically different than those who don\u2019t.\u201d <\/p>\n\n\n\n Jelliffe-Pawlowski conducted the research while working as a professor of epidemiology and biostatistics at the University of California, San Francisco.<\/p>\n\n\n\n \u201cWe found that, at birth, we\u2019re able to stratify kids as being very low risk \u2014 not zero risk, but very low risk \u2014 versus relatively very high risk for SIDS,\u201d she said, adding that the screenings could indicate which babies need closer monitoring. <\/p>\n\n\n\n The findings are based on data from infants born in California from 2005 to 2011. The researchers compared the results of newborn screening tests for 354 infants who died of SIDS with 1,416 infants who did not. They ran the data through a model to control for external factors that could influence a baby\u2019s risk, like the mother\u2019s age, race or health status.<\/p>\n\n\n\n Jelliffe-Pawlowski said the research indicates that babies with an increased risk of SIDS may have some difficulty using and breaking down sugars or fats.<\/p>\n\n\n\n \u201cMaybe we\u2019re looking at some food sensitivities,\u201d she said, but added that much more research is needed into the link between SIDS risk and metabolism. \u201cIt\u2019s impossible to tell at this point.\u201d<\/p>\n\n\n\n Even if further studies confirm that metabolic abnormalities are a risk factor, the challenge is what to do if they appear on a baby\u2019s newborn screening results. For the most part, SIDS is hard to prevent.<\/p>\n\n\n\n \u201cI worry a little bit about what this could do to stress and anxiety, if we say, \u2018Hey, my kid\u2019s at an increased odds for this, but there\u2019s nothing I can do,\u2019\u201d said Dr. Stephanie Napolitano, a neonatology physician at Nationwide Children\u2019s Hospital who was not involved in the new study.<\/p>\n\n\n\n Parents can lower the risk of SIDS by placing babies on their backs when they sleep and making sure their room isn\u2019t too hot, but those interventions aren\u2019t necessarily sufficient.<\/p>\n\n\n\n Dr. Joanna Parga-Belinkie, a neonatologist at Children\u2019s Hospital of Philadelphia who also wasn\u2019t involved, similarly questioned whether newborn screenings can provide enough answers.<\/p>\n\n\n\n \u201cIt\u2019s likely that newborn screening itself is not really going to be sensitive or specific enough to be a great screen for SIDS,\u201d she said, adding that, at best, it might tip off doctors that they need to do additional testing for babies with an abnormal metabolic profile.<\/p>\n\n\n\n Researchers generally think that SIDS results from a combination of factors, not just one. It is more likely to occur when infants are at a critical stage of development, making them more vulnerable, and when they\u2019re exposed to a stressor, like sleeping face down, which can lower oxygen and raise carbon dioxide in their blood. Many experts also think that some underlying abnormality, such as a genetic, metabolic or neurological issue, is likely at play.<\/p>\n\n\n\n The new study \u201cdoesn\u2019t knock out the possibility that there\u2019s an underlying genetic phenomenon,\u201d said Dr. Debra Weese-Mayer, chief of the pediatric autonomic medicine division at Lurie Children\u2019s Hospital of Chicago, who wasn\u2019t involved in the research. <\/p>\n\n\n\n \u201cBut every baby that\u2019s born isn\u2019t going to get a deep-dive genetic evaluation \u2014 they do get newborn screenings,\u201d she added.<\/p>\n\n\n\n Some recent research on SIDS has pointed to other risk factors, including serotonin, which helps regulate heart rate and breathing. A study last year suggested that an altered brain receptor involved in the serotonin system could prevent some infants from gasping for air<\/a> when they don\u2019t get enough oxygen during sleep. <\/p>\n\n\n\n A 2022 study, meanwhile, suggested that babies who died of SIDS had lower levels of a chemical messenger<\/a> involved in the autonomic nervous system, which regulates involuntary processes like blood pressure and breathing.<\/p>\n\n\n\n Experts said it\u2019s too soon to say whether the metabolic differences detected in the new study are related to the neurological differences identified in previous research.<\/p>\n\n\n\n \u201cYour body is so interconnected. Your autonomic nervous system obviously has an impact and plays a role in your metabolism,\u201d Napolitano said. \u201cFiguring out how all of those pieces fit together is still the question.\u201d<\/p>\n\n\n\n