Alcohol and pregnancy don't mix. And neither does alcoholism and a baby's first year of life. Mothers who don't have alcohol problems are much more likely to see their babies grow up.
Those are the findings of a new study looking at risk factors for babies' deaths.
Mothers who had alcohol problems were much more likely to have a baby die from sudden infant death syndrome (SIDS) than mothers without alcoholism. Babies of alcoholic mothers were also more likely to die from other causes.
The higher risk of death in the babies was true regardless of whether the mothers were drinking excessively during pregnancy or only after their child was born.
The study, led by Colleen M. O'Leary, MPH, PhD, of the Centre for Population Health Research at Curtin University in Perth, Australia, looked at whether mothers' use of alcohol played any part in the risk of their babies dying.
The researchers compared two groups of mothers for the study. One group of 21,841 mothers were alcoholics, based on meeting nine out of 10 symptoms for alcohol-use disorder from an international classification system.
These mothers were compared to 56,054 mothers who did not have an alcohol-related diagnosis but were similar to the alcoholic mothers based on their age, race/ethnicity and the year they had their children.
Among these two groups, a total of 303 babies died from (SIDS) and 598 babies died from other causes not related to SIDS.
The researchers found that the babies most likely to die from SIDS or other causes were those whose mothers had an alcoholism diagnosis while she was pregnant or within the baby's first year of life.
Babies of the mothers who were alcoholics while pregnant were about seven times more likely to die from SIDS than the babies of mothers without an alcohol-use disorder. These babies were also more than twice as likely to die from other causes besides SIDS.
When the researchers adjusted their findings to account for mothers who smoked during pregnancy as well, the risk of a SIDS death for babies of mothers who drank to excess while pregnant was still about four times greater than the risk for children of mothers who didn't have alcoholism.
Babies of the mothers diagnosed with an alcohol use disorder in the first year after pregnancy – but who were not alcoholics during pregnancy – were over eight times more likely to die of SIDS than the babies of mothers with no alcohol-use disorders.
The researchers calculated that about 16.4 percent of the SIDS deaths of babies were due to the mother's alcoholism. Mothers' alcohol-use disorders were also responsible for approximately 3.4 percent of the babies who died for reasons other than SIDS, the researchers determined.
The babies of alcoholic mothers who died of non-SIDS causes often had multiple health issues. Nearly 40 percent of them had conditions like prematurity, poor growth in the womb, slow growth and congenital heart disease.
Similarly, about 60 percent of these babies were exposed to other environmental dangers, including smoke, dehydration, viral infections and neglect.
"Maternal alcohol-use disorder is a significant risk factor for SIDS and infant mortality excluding SIDS," the researchers concluded. "The results of this study indicate that maternal alcohol-use disorder increases the risk of SIDS and infant mortality not classified as SIDS through direct effects on the fetus and indirectly through environmental risk factors."
The study was published February 25 in the journal Pediatrics. The research was funded by the Australian National Health and Medical Research Council and grants from Curtin University and the Western Australian Drug and Alcohol Office. The authors declared no conflicts of interest.