SIDS Cases Typically Spike on New Year's Day

Alcohol consumption by caregivers a likely culprit

Fran Lowry

December 29, 2010

December 29, 2010 — The number of babies who die of sudden infant death syndrome (SIDS) typically surges by 33% on New Year's Day, probably because their caregivers celebrate with alcohol the night before, according to a new epidemiologic study published in Addiction.

"Our study is the first to provide large-scale evidence that identifies alcohol consumption as a possible risk factor for SIDS in the United States," lead author David P. Phillips, PhD, professor of sociology at the University of California–San Diego, told Medscape Medical News.

"The most striking pattern to come out of our study was the very large spike in alcohol consumption — way bigger than on any other day of the year — on New Year's and the very big spike in SIDS death — way bigger than on any other day of the year. This was not known before: that SIDS spiked by 33% above what you would normally finding the winter."

Dr. Phillips said alcohol is known to impair judgment and worsen pediatric care, but that studies about the effects of alcohol consumption and SIDS have shown conflicting results, with some concluding that alcohol is not a risk factor and others concluding that alcohol is a risk factor only when combined with things such as sharing a bed with an infant.

"These studies were small, and they raise an important hypothesis, which is that alcohol-impaired caretakers are less able to protect vulnerable infants. We call this the 'alcohol-SIDS hypothesis,' or the 'AS hypothesis,' " Dr. Phillips said.

Striking Pattern

To test whether alcohol is a risk factor for SIDS, Dr. Phillips and his colleagues analyzed 3 official US data sets that included a total of 129,090 SIDS cases:

  • all US computerized death certificates, which provided day of week of death for the years 1973 to 2006, and exact date of death for 1973 to 2004;

  • the linked birth and infant death data set, which links information from birth and death certificates for babies who die when younger than 1 year and records information about the infant and the infant's mother (eg, whether or not she consumed alcohol); and

  • the Fatality Analysis Reporting System, available online for years 1994 to 2008, which provides information on all US motor vehicle accidents involving at least 1 fatality.

Although the steep increase in SIDS deaths at New Year's was the most striking pattern to emerge from the study, other findings from the study also suggest an alcohol–SIDS connection, Dr. Phillips said.

For example, the linked birth and infant death data set showed that mothers who drink alcohol are twice as likely to have SIDS babies as mothers who do not drink alcohol, Dr. Phillips said.

Alcohol consumption was also implicated as a cause of infant death in the Fatality Analysis Reporting System data set, which showed that in crashed vehicles containing at least 1 alcohol-impaired adult, there were 1.20 children improperly seat belted for every child properly seat belted. This ratio was significantly lower for non–alcohol related crashes.

"Adults who have alcohol in them are less likely to strap in any children in the car, so that shows that adults who are under the influence of alcohol are less good at protecting infants. And this is what we are claiming in the case of the SIDS–alcohol connection," Dr. Phillips said.

"The alcohol would make [the adults] less careful. That's at least a part of it, we think. We know that, for example, if you put the child down on its face, that's not a good thing, and we know that if you are filled up with alcohol, you're less careful at doing any task, including the task of taking care of a child, driving a car, anything. So if you're filled up with alcohol, you're a less competent caretaker, and presumably you might then be more likely to put the child down incorrectly," he said.

"In addition, if you're filled up with alcohol and you're sleeping in the bed with the child, which some parents do, you may be less aware that you've rolled over onto the child, or, if the child is uttering some sounds of distress and you're not compos mentis, you may be less sensitive to these cries for help from the child. All of those things would plausibly connect being a SIDS child with a caretaker who is under the influence of alcohol."

Leap of Faith

The methodology of this study is unusual, commented Rachel Moon, MD, professor of pediatrics at the George Washington University School of Medicine and Health Sciences, Washington, DC, and a recognized authority on SIDS.

"They took 3 different databases and then they made conclusions based on conclusions from these separate databases, and I think they actually may have assumed too much," she told Medscape Medical News.

"For instance, there is no way from the death certificate data [to determine] whether the mother consumed alcohol on the night the baby died. That information is not there."

Dr. Moon said the authors are making an assumption, and although that assumption is not unreasonable, it is still an assumption.

"This is not a case-control study where they look at individual data. They are making a big leap of faith," she said.

The cause of SIDS remains a mystery, although improvements in diagnosis during the past 15 years have made true cases of SIDS much rarer than had been thought, Dr. Moon noted.

"Now we are much better at scene investigation. A lot of what we thought was SIDS initially is turning out to be suffocation. But there are still instances where the baby just dies and we have no idea, there is nothing to explain it," she said.

"SIDS will still occur, even if we are very careful and do everything right. But this is very rare. Most babies who die of SIDS will have some risk factors — they're lying on their stomach, or they're sleeping with their parents, or sleeping with pillows and blankets. But for a baby with no risk factors to die of SIDS is very rare."

Dr. Phillips and Dr. Moon have disclosed no relevant financial relationships.

Addiction. Published online November 9, 2010.


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