Parents and caretakers who drink alcohol may put infants at a higher risk for sudden infant death syndrome (SIDS), new research suggests.

Researchers at the University of California-San Diego found that SIDS cases occur 33 percent more often on New Year's Day than any other day of the year, which is also when more people drink alcohol than at any other time of year.

Because the rate of SIDS has dropped since the 1990s to some 2,500 cases per year-about 7 per day-that 33 percent spike translates to only two more cases of SIDS on New Year's than any other day. However, the researchers report finding other links between caretaker drinking and incidence of SIDS, in the journal Addiction.

SIDS cases and drinking occur more often on weekends than during the week, and infants whose caretakers drink were more than twice as likely to die from SIDS as those whose caretakers do not drink, the study concludes.

Though rare, SIDS still makes up a significant portion of all cases of infant death. In their analysis of U.S. records of infant deaths between 1973 and 2006, the researchers found 129,000 SIDS cases and 295,000 non-SIDS cases -- meaning that SIDS accounted for nearly one-third of infant deaths in that time period.

David Phillips, a sociologist and lead author of the study, hopes his findings will encourage doctors, parents, and researchers to focus more on alcohol as a risk factor for the syndrome.

This study is a pretty clean indicator that SIDS might have an alcohol component, Phillips told Reuters Health.

Large-scale efforts to reduce the risk of SIDS began in 1994 when the National Institute of Child Health and Human Development launched Back to Sleep, a campaign focused on teaching parents to put infants to sleep on their backs, rather than on their side or stomach, in order to reduce the chance of suffocation.

Phillips' concern is that when parents and caretakers drink alcohol they are less likely to pay attention to these recommendations, which include not sleeping in the same bed as an infant and limiting the number of pillows and blankets in the crib.

We know that people are not as good at performing tasks when under the influence of alcohol, he said. This includes caretaking.

Though the study results reveal previously unknown trends in SIDS, Dr. Rachel Moon, a pediatrician at Children's National Medical Center in Washington, DC, said it has some important limitations. She pointed out that because the study doesn't include detailed information about the individual cases and families involved, it is difficult to assess the actual relationship between drinking and SIDS.

You can say there is an association, but you can't really say, based on this, that alcohol is a major risk factor, said Moon.

Moon, who chairs the Academy of American Pediatrics SIDS Task Force, said that she and her colleagues will still take the study into consideration as they prepare an update of the guidelines for taking care of infants and reducing the risk of SIDS.

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