Sudden Infant Death Syndrome (SIDS): Simple Tests Could Identify Babies at Risk

New research from the University of Virginia School of Medicine showing the fingerprints of sudden infant death syndrome in blood samples could pave the way for simple tests to identify babies at increased risk.

Researchers Analyzed Blood Serum Samples from Affected Infants

The results also represent an important step toward elucidating the causes of sudden infant death syndrome (SIDS), which is the leading cause of death among babies between one month and one year of age. Most SIDS cases usually occur in the first six months of life. Although SIDS is very rare, children who are born prematurely or with a low birth weight are at increased risk of dying from sudden infant death syndrome. Some experts believe that babies who die of SIDS have problems responding to certain environmental stresses and regulating their heart rate, breathing and temperature. However, the exact causes are still not fully understood.

The UVA researchers analyzed blood serum samples from infants who had died of SIDS and were able to identify specific biological indicators that were linked to the babies’ deaths – and were potential causes of them. Tests to identify such signs in infants could ultimately help save lives, the researchers said. “Our study is the largest to date that has attempted to identify how these small molecules in the blood can serve as biomarkers for SIDS,” said researcher Keith L. Keene, PhD, founding director of the UVA Center for Health Equity and Precision Health and now at East Carolina University. “Our findings support the role of several key biological pathways and provide insight into how these biological processes may contribute to increased risk or serve as a diagnosis of SIDS.”

35 Predictors for SIDS

The new study highlights the potential of “metabolomics,” the analysis of substances produced by cells and known as metabolites, to better understand and treat complex diseases. In their SIDS study, the UVA researchers analyzed blood serum samples from 300 babies collected as part of the Chicago Infant Mortality Study and the National Institutes of Health’s NeuroBioBank. The researchers examined the concentration of 828 different metabolites in key biological processes such as communication between nerve cells, stress response and hormone regulation – processes that could contribute to SIDS. After adjusting for factors that could influence the results, such as the age, gender, race and ethnicity of the infants, the researchers identified 35 predictors of SIDS. Among these “biomarkers” was ornithine, a substance crucial to the body’s ability to dispose of ammonia in the urine.

The amino acid had already been identified as a potential factor in SIDS. Another predictor was a lipid metabolite essential to brain and lung health. This metabolite is already considered a potential indicator of fetal heart defect development in the first trimester of pregnancy. The researchers found differences in certain fats, called sphingomyelins, that are critical to brain and lung development. Differences in these fats may disrupt these critical processes, putting some infants at risk for SIDS. The UVA scientists caution that more research is needed to determine whether the metabolites contribute to SIDS. However, the findings are an important step in unraveling the mysteries of SIDS and developing blood tests that could spare new parents the grief.