A new study from the UNC Nutrition Research Institute (NRI) looks at how prenatal alcohol exposure (PAE) changes placental metabolism and what that means for fetal brain development. The research, a collaboration between Nipun Saini, PhD, Susan Smith, PhD, and Sandra Mooney, PhD, was recently published in The Journal of Nutrition. The three NRI labs analyzed placental tissue and uncovered key metabolic shifts that could help explain why alcohol exposure during pregnancy affects brain growth.
💡 What is Placental Metabolism?
Placental metabolism refers to the biochemical processes that allow the placenta to convert nutrients from the mother’s bloodstream into energy and essential molecules for fetal growth. It plays a critical role in regulating how nutrients and oxygen reach the fetus, supporting development throughout pregnancy. Changes in placental metabolism can impact fetal health, particularly brain development.
This study builds on earlier work from Smith and Mooney, which showed that PAE doesn’t just impact the fetus directly – it also disrupts how the placenta functions. Their research linked alcohol exposure to stress at the cellular level, leading to damage in the fetal brain. The new study takes this a step further by identifying specific metabolic pathways that change when the placenta is exposed to alcohol.
“A lot of past research has focused on genes, and this doesn’t fully capture the placenta’s ability to supply nutrients to the developing fetus. Our focus on metabolites lets us identify what nutrients are missing from the alcohol-exposed fetus. This new information will guide us in designing better interventions to improve fetal outcomes,” Smith explains.
How Alcohol Changes Placental Metabolism
The researchers compared placental tissue from alcohol-exposed and control mice, finding major differences in how the placenta processes energy. Normally, the placenta relies on carbohydrates, but after alcohol exposure, it shifts toward lipid metabolism instead. This change was closely tied to lower fetal brain weight – a hallmark of fetal alcohol spectrum disorder – but didn’t affect overall body weight.
Saini describes the significance of this finding, “Maternal metabolism is one of the under appreciated topics in prenatal alcohol research. This study fits in the missing piece of the puzzle and show alcohol’s impact on placental metabolism to selectively reduce fetal brain weight, and not body weight. This research highlights the vital role of a mother’s metabolism and the placenta in supporting fetal brain development.”
By combining expertise in metabolism (Smith), brain development (Mooney), and metabolomics (Saini), the team showed that placental metabolism plays a key role in fetal brain growth. Their findings provide new details about how alcohol exposure affects development at a molecular level and reinforce the need for continued research on these metabolic changes. Understanding these metabolic effects could help identify ways to reduce their impact on fetal growth.
For more details, read the full study:
Saini, N., Mooney, S. M., & Smith, S. M. (2025). Alcohol reprograms placental glucose and lipid metabolism which correlate with reduced fetal brain but not body weight in a mouse model of prenatal alcohol exposure. The Journal of Nutrition. https://doi.org/10.1016/j.tjnut.2025.02.011.