new data suggest.
Findings of the study by Scott P. Oltman, MS, of the Department of Epidemiology & Biostatistics, University of California, San Francisco, and colleagues were published in JAMA Pediatrics.
The case-controlled study showed a link between aberrant metabolic analytes at birth and SIDS. Researchers used data from the California Office of Statewide Health Planning and Development and the California Department of Public Health and included 2.3 million infants born between 2005 and 2011 in the dataset.
Of the 2.3 million infants, 354 had SIDS. The researchers found that 14 newborn screening metabolites were significantly associated with SIDS. After the screens, the babies who had elevated metabolite markers, compared with the control babies had 14.4 times higher odds of having SIDS, the researchers reported.
“It’s really promising research,” Joanna J. Parga-Belinkie, MD, an attending neonatologist who was not involved in the study, said in an interview. She practices in the Division of Neonatology at Children’s Hospital of Philadelphia in Pennsylvania. “It doesn’t really give us the answer to what causes SIDS, but I think in the long term it’s going to inform a lot of research that will help us understand whether there are biomarkers that can predict SIDS.”
Other studies have looked at different metabolic markers to see if they can help predict SIDS, she said, but the innovation in this study is that it uses newborn screens, which are collected on all babies born in a hospital. Dr. Parga-Belinkie added that another strength of the study is its large sample size and matched controls to compare the SIDS cases with healthy babies.
“That said, newborn screens are a screening test, they are not diagnostic,” Dr. Parga-Belinkie said. “We definitely need further testing to see if (the metabolic biomarkers) really make that link to SIDS.”
It will be important to test this in a prospective study over time and in real time, she said, which is something the authors acknowledge. They list the retrospective design of the study as a major limitation.
These study results won’t change the counseling for families on decreasing risk, Dr. Parga-Belinkie said, “because there’s not a clear biomarker that has emerged and we don’t have a clear link yet.” Safe sleep hygiene will continue to be the primary focus of counseling parents, such as placing the baby on its back on a firm, flat surface with no loose bedding or stuffed animals.
The study authors said several things will need to be clarified with future research, noting that a majority of the infants in the California database were of Hispanic ethnicity. Testing other populations will help determine generalizability.
Also, there has been ambiguity in the definition of SIDS, which has led to inconsistencies in classifying a death as SIDS or death from an unknown cause of suffocation or asphyxiation.
They added: “It may also be the case that these markers are predictive and reliable but not causal in nature and distinguishing between the two is a crucial topic for future investigation.”
This work was supported in part by the California Preterm Birth Initiative within the University of California, San Francisco, and by the National Institutes of Health. Mr. Oltman reported having a patent pending for a newborn metabolic vulnerability model for identifying preterm infants at risk of adverse outcomes and uses thereof. One coauthor reported having a patent pending and a patent issued; another reported having a patent pending for a newborn metabolic vulnerability model for identifying preterm infants at risk of adverse outcomes and uses thereof. Dr. Parga-Belinkie declared no relevant financial disclosures.