Not a happy holiday thought, but an important one: The number of babies who die of SIDS, or sudden infant death syndrome, surges by 33 percent on New Year's Day. The suspected reason? Alcohol consumption by caretakers the night before.
Led by sociologist David Phillips of the University of California, San Diego, the study documenting the dramatic rise in SIDS deaths on New Year's is published in the journal Addiction. The spike, write Phillips and his coauthors, is beyond the normal winter increase in SIDS.
The study examined 129,090 SIDS cases from 1973 to 2006 using three multiyear nationwide datasets: computerized death certificates, the linked birth and infant death dataset, and the Fatality Analysis Reporting System. The authors say it is the first, large-scale U.S. study to explore possible connections between alcohol and SIDS.
Though SIDS has decreased significantly since the 1994 implementation of the "Back to Sleep" campaign, which urges caregivers to put infants on their backs to sleep, among other "safe-sleep" recommendations, SIDS continues to be the leading cause of death for children aged 1 month to 1 year. Also known as "crib death" and "cot death" because it strikes seemingly healthy babies in their sleep, SIDS is usually ruled the cause of death only when other causes are ruled out.
Phillips and his coauthors found three types of evidence linking SIDS to alcohol. In addition to rising, just like alcohol consumption, more on New Year's than at any other day of the year, SIDS and alcohol consumption also increase every weekend. And the SIDS death rate is abnormally high for children of alcohol-consuming mothers: Babies of mothers who drink are more than twice as likely to die of SIDS.
The study also found a rise in SIDS just after April 20 (or 4/20), a counterculture celebration of cannabis, and after July 4, which is also known as an inebriated time, though the rise on neither of these dates is as dramatic as on New Year's.
To see if parental sleeping-in might be at fault – rather than intoxication itself – the authors also checked to see what happens during the autumn shift to daylight savings, when many sleep later because an hour has been added to the day. There was no rise in SIDS, Phillips said.
The authors acknowledge important limitations to the current study. The large datasets contain very little information per case, Phillips said, so "we could not specify the detailed mechanisms and cannot determine whether alcohol is an independent risk factor for SIDS, a risk factor only in conjunction with other factors or a proxy for risks associated with occasions when consumption increases."
The study doesn't, and can't, point definitively to alcohol consumption as a cause of SIDS, but the connections are concerning, Phillips said. He worries that parents may not be as good at parenting – following the "Back to Sleep" recommendations, for example – when they've been drinking.
"We know that when people are under the influence of alcohol their judgments are impaired and they are not as good at performing tasks. This would include caretaking," Phillips said.
Phillips urges further studies that might shed additional light on the relationship between alcohol and SIDS. Nonetheless, he said, it is not unreasonable even now to suggest that SIDS investigations inquire about the recent alcohol consumption of the infant's caretakers and that pediatricians advise new parents that alcohol impairs their abilities and may endanger their children.
"The 'Back to Sleep' campaign was largely successful," the authors write. "A similar campaign might now be implemented: There should be increased efforts to inform caretakers that alcohol impairs parental capacity and might be a risk factor for SIDS."
Phillips' coauthors are Kimberly M. Brewer and Paul Wadensweiler of UC San Diego.
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