Alcohol consumption while breastfeeding can have a negative impact on the health of newborns. When a mother consumes alcohol, some of it passes into her breast milk, where it is ingested by the breastfeeding baby when they nurse. What are the ramifications of mothers drinking alcohol while breastfeeding? To find out, a team of researchers at the University of California, Riverside conducted a mouse study.
Alcohol consumption during pregnancy has been shown in studies to alter the brain and behavioral development of the fetus. The Centers for Disease Control and Prevention currently advises against maternal alcohol consumption during pregnancy, citing the lack of a known safe level of consumption. But what are the consequences of mothers drinking alcohol while breastfeeding?
To find out, a team of researchers at the University of California, Riverside conducted a mouse study.
The team, led by Kelly Huffman, a psychology professor, discovered that infants’ exposure to alcohol through breastmilk can have long-term effects on their development. Young mice exposed to alcohol during development have smaller body and brain growth, as well as shorter cortical lengths – a measure of brain size. The findings were published in Frontiers in Neuroscience.
We are aware of the disconnect between the conclusions drawn from scientific literature and the behaviors of many new mothers. We hope that our work will increase public awareness of safe maternal practices.
Kelly Huffman
According to research, approximately 36% of breastfeeding mothers in the United States drink alcohol. The figures in Canada and Australia are 20% and 60%, respectively. Women who drink while pregnant are more likely to drink while breastfeeding. Also, many women who choose to abstain from drinking during pregnancy report beginning to drink again shortly after giving birth.
The scientists concentrated on lactational ethanol exposure, or LEE, and created a novel postnatal alcohol exposure model in breastfeeding mice. Offspring in this mouse model were exposed to ethanol via nursing from postnatal day (P) 6 to P20 (weaning), a period equivalent to human infancy.
LEE mice had lower body and brain weights, as well as shorter neocortical lengths at weaning that lasted until early puberty (age P30). Male brain weights were reduced at both ages, and female brain weights were reduced at P20; however, female brain weights recovered to control levels at P30. This discovery points to sex-specific differences caused by LEE.
“The reduced body weights in both males and females at P20 and P30 are reflected in human studies in which children exposed to ethanol through contaminated breast milk have lower body weights and growth trajectories,” Huffman explained. According to her, the reduction in body and brain weights could be explained by the gut’s inability to extract nutrients efficiently when alcohol is consumed. A decrease in protein synthesis in the small intestine may prevent micro- and macronutrient absorption.
Regarding how the LEE mice’s behavioral development is affected, Huffman stated that behavioral tests her team performed on LEE mice indicate they engage in higher risk-taking behavior, as well as abnormal stress regulation and increased hyperactivity.
“Thus, women should refrain from consuming alcohol during breastfeeding until more research can help recommend safe maternal practices in early infancy,” she added.
Although researchers advocate for women to abstain from alcohol consumption during the prenatal period as well, Huffman stated that there are conflicting views on appropriate, safe drinking behaviors during the breastfeeding period.
“We are aware of the disconnect between the conclusions drawn from scientific literature and the behaviors of many new mothers,” she explained.
Fetal alcohol exposure from maternal consumption during pregnancy has been studied for over 50 years. Huffman’s laboratory at UCR has made ground-breaking discoveries, including the fact that Fetal Alcohol Spectrum Disorders, or FASD, are heritable, passing down to at least the third generation.
“We hope that our work will increase public awareness of safe maternal practices,” Huffman said.
