A new study into fetal growth shows a predictor of healthy brain development is placenta oxygen levels, which researchers measured using MRI. Oxygenation levels not only seem to be a predictor of cortical growth and cognition, but likely childhood behavior as well. The findings are published in JAMA Network Open. [1]
“Many factors can disrupt healthy brain development in utero, and this study demonstrates the placenta is a crucial mediator between maternal health and fetal brain health,” study senior author Emma Duerden, PhD, from Western University’s Lawson Health Research Institute said in a statement.
While a fetus is typically monitored with ultrasound, scientists for this study opted to use an MRI, as it produces more detailed images of the fetus and allowed the team to better assess placental and brain health to find any correlation.
“While ultrasound provides some measure of placental function, it is imprecise and prone to error, so MRI is just a bit more specific and precise,” Emily Nichols, PhD also from Western University and the study’s lead author explained in the statement . “You wouldn’t use MRI necessarily to diagnose placental growth restriction, you would use ultrasound, but MRI gives us a much better way to understand the mechanisms of the placenta and how placental function is affecting the fetal brain.”
Placental dysfunction can lead to variations in blood flow distribution to the fetus, with oxygenated blood prioritized for the brain in a process known as brain sparing. However, the impact on specific brain regions, particularly cortical versus subcortical areas, remains unclear. Previous studies using ultrasounds have suggested cortical regions may respond to changes in placental oxygenation, but images were not sensitive enough to make any firm correlations.
For this study, 49 female participants were scanned twice using MRI in their third trimester, revealing a significant association between placental oxygenation levels and fetal brain volumes. Specifically, the findings suggest that cortical brain regions are more susceptible to variations in placental oxygenation compared to subcortical regions. This implies that mapping oxygen saturation levels in the placenta could serve as a biomarker for not only fetal brain development and function, but it can also be a method for identifying fetal hypoxia.
“[With these findings] we now have a better understanding of how the placenta affects the cortex. With this basic knowledge, we now have an idea of how these two things are related and we can identify or benchmark healthy levels that lead to brain cortical growth,” Nichols added. “The subcortical regions of the brain appear to be unaffected by placental growth, at least in the healthy samples from our study.”
Interestingly, placental oxygenation may not affect the development of gray and white matter structures of the brain. However, subcortical structures in the brain, responsible for temperament or motor functions, seem to be impacted by placental health as early as the second trimester.
“An unhealthy placenta can place babies at risk for later life learning difficulties, or even something more serious, like a neurodevelopmental disorder,” Duerden added. “This research can open a lot of doors as we still don’t really understand everything there is to know about the placenta. We are just scratching the surface.”
While the findings are significant, the authors note the study is limited by the small sample size as well as a potential selection bias. Further research is needed to explore any clinical implications thoroughly.
The full study is available at the link below.
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