Sudden infant death linked to maternal alcohol abuse

Robin Wulffson MD's picture
sudden infant death syndrome, SIDS, alcohol abuse, infant mortality

Sudden infant death syndrome (SIDS) is the unexpected, sudden death of a child under age one; it is currently a significant cause of death among infants in the United States. Researchers affiliated with the University of Perth investigated the association between maternal alcohol-use disorder and both SIDS and infant mortality not classified as SIDS. They published their findings online on February 25 in the journal Pediatrics.

The authors noted that improvements in the rate of infant mortality (death in first year of life) have not occurred in recent years. Therefore, they conducted a study to investigate the association between maternal alcohol-use disorder and sudden infant death syndrome (SIDS) and infant mortality not classified as SIDS using linked, population-based health and mortality data.

Mothers who suffered from alcohol abuse were identified through the presence of an International Classification of Diseases 9/10 alcohol diagnosis, a proxy for alcohol-use disorder, recorded on health, mental health, and/or drug and alcohol datasets (1983–2005). Comparison mothers without an alcohol diagnosis were matched with exposed mothers in regard to maternal age, maternal race, and year of birth of their children. All offspring with their birth recorded on the Midwives Notification System and comprised exposed (21,841 infants) and comparison (56,054 infants) cohorts. Cases of SIDS (303 infants) and infant mortality excluding SIDS (598 infants) were identified through linkage with the Western Australian Mortality Register.


The researchers found that the highest risk of SIDS occurred when a maternal alcohol diagnosis was recorded during pregnancy or within one year post-pregnancy. An alcohol diagnosis recorded during pregnancy more than doubled the risk of infant deaths (excluding SIDS). They noted that maternal alcohol-use disorder is attributable for at least 16.41% (9.73%–23.69%) of SIDS and 3.40% (28%–4.67%) of infant deaths not classified as SIDS.

The authors concluded that maternal alcohol-use disorder is a significant risk factor for SIDS and infant mortality excluding SIDS. They noted that previous research suggests babies exposed to alcohol in the womb may have abnormalities in the brainstem, which could lead to problems regulating basic body functions like breathing. However, in this study, the investigators found a link between infant deaths and a mothers’ drinking as long as one year after giving birth. Therefore, biological factors cannot explain the deaths. The authors theorized that the mothers may be creating unsafe environments for their children. For example, a drunken parent may fall asleep with their baby in bed, and accidentally roll over and suffocate the child.

SIDS rates have dropped dramatically since 1992, when parents were first told to place their infants on their backs or sides when they are put to bed. However, unfortunately, SIDS remains a significant cause of death in infants under one year old. Approximately 4,500 infant deaths fall into this category every year in the U.S., according to the CDC. SIDS is most likely to occur between 2 and 4 months of age. SIDS affects boys more often than girls. Most SIDS deaths occur in the winter.

Take home message:
This is another study that links poor lifestyle choices with infant death. Maternal smoking during and after pregnancy has been reported to increase the risk of SIDS. Exposure to secondhand smoke in the home or automobile also increases the risk.

Reference: Pediatrics