Summary: New research shows that placental oxygenation during the third trimester strongly predicts development of the fetal cerebral cortex and may forecast later childhood cognition and behavior.
Using magnetic resonance imaging (MRI) to assess placental function, the study provides clearer evidence of how the placenta mediates the effects of maternal health on fetal brain development and highlights opportunities for earlier detection and intervention for neurodevelopmental risk.
The findings emphasize the placenta’s essential role in early brain growth and suggest MRI-based placental measures could become important biomarkers in prenatal care.
Key Facts:
- MRI for placental assessment: MRI offers more specific and reliable measurements of placental oxygenation and growth than standard ultrasound, enabling more detailed study of how placental function relates to fetal brain development.
- Third-trimester oxygenation and cortical growth: Healthy placental oxygen levels in the third trimester are associated with larger cortical and prefrontal cortical volumes — regions crucial for learning, memory, and higher-order cognition.
- Potential for earlier intervention: Monitoring placental health with advanced imaging may allow earlier identification of fetuses at risk for cognitive or behavioral difficulties, opening new pathways for prenatal monitoring and targeted treatments.
Source: University of Western Ontario
Overview: A newly published study finds that oxygenation in the placenta during the final three months of pregnancy is an important predictor of fetal cortical growth — the development of the cerebral cortex — and likely relates to later childhood cognition and behavior.
“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,” said Emma Duerden, Canada Research Chair in Neuroscience & Learning Disorders at Western University, a Lawson Health Research Institute scientist and the study’s senior author.
Previous studies using ultrasound linked placental health to childhood cognitive outcomes. For this investigation, Duerden, lead author Emily Nichols and a multidisciplinary team from Western and Lawson used MRI to measure placental oxygenation (T2* mapping) alongside fetal brain imaging. MRI provides a more comprehensive and precise picture of placental function than conventional ultrasound, allowing researchers to examine relationships between placental oxygenation and specific brain regions.
“Ultrasound gives useful clinical information, but it can be imprecise. MRI allows us to better understand the mechanisms by which placental function influences the developing fetal brain,” Nichols said.
The study, published in JAMA Network Open, draws on expertise from Western’s Faculty of Education, Schulich School of Medicine & Dentistry, Western Engineering and Lawson Health Research Institute.
The placenta is the primary conduit for oxygen and nutrients to the fetus and serves as a key endocrine organ during pregnancy. If placental development is impaired, the fetus may receive insufficient oxygen and nutrients, which can affect brain growth.
Risk factors such as poor maternal nutrition, smoking, substance use, chronic hypertension, anemia and diabetes can contribute to placental dysfunction and fetal growth restriction. Fetal growth restriction affects roughly six percent of pregnancies and is estimated to impact about 30 million pregnancies worldwide each year.
“If the placenta does not develop properly, the fetal brain may not receive the oxygen or nutrients it needs, which could influence cognition and behavior during childhood,” Duerden added.
Impact on cortical and subcortical development
The researchers found that healthier placental oxygenation in the third trimester was specifically associated with greater cortical and prefrontal cortex volumes. These cortical regions support learning, memory and complex cognitive functions, suggesting third‑trimester placental health has important implications for developmental outcomes.
By contrast, placental oxygenation measured in these healthy samples did not appear to affect subcortical maturation — the deeper gray and white matter structures. The team notes subcortical regions such as the amygdala and basal ganglia may be more vulnerable to placental or maternal factors earlier in pregnancy, particularly in the second trimester.
“An unhealthy placenta can increase risk for later learning difficulties or, in some cases, neurodevelopmental disorders,” Duerden said. “These findings give us a clearer picture of when and how placental function may influence different brain regions.”
Nichols added: “With MRI-based measures like T2*, we can begin to benchmark healthy placental oxygenation levels that support cortical growth. That basic knowledge is essential for identifying early biomarkers of risk.”
For this longitudinal study, pregnant participants were scanned twice during the third trimester at Western’s Translational Imaging Research Facility. Such repeated in utero MRI scans are rare and create a rich dataset to examine growth over time.
“Very few groups worldwide collect two fetal MRI scans in the third trimester, so our dataset is unusually valuable for understanding brain and placental development trajectories,” Duerden said.
About this neurodevelopment research news
Author: Jeffrey Renaud
Source: University of Western Ontario
Contact: Jeffrey Renaud – University of Western Ontario
Image: The image is credited to Neuroscience News
Original Research: Open access. “T2* Mapping of Placental Oxygenation to Estimate Fetal Cortical and Subcortical Maturation” by Emma Duerden et al., JAMA Network Open
Abstract
T2* Mapping of Placental Oxygenation to Estimate Fetal Cortical and Subcortical Maturation
Placental dysfunction reduces the supply of nutrients and oxygen to the fetus. The timing of this dysfunction influences which brain structures are most vulnerable and affects developmental outcomes. Evidence from Doppler ultrasound in severe cases of placental dysfunction and intrauterine growth restriction suggests the fetus redistributes blood in a hierarchical pattern, prioritizing subcortical regions important for homeostasis at the expense of cortical regions responsible for higher-order functions.
Doppler studies point to cortical variability in response to changes in placental oxygenation, but the quality of evidence has been moderate to low, indicating a need for more sensitive imaging approaches. Recent research links MRI-derived placental T2* measures to birth weight, suggesting T2* could also reflect variations in fetal brain development.
This study tested whether MRI-based placental T2* values are associated with fetal cortical and subcortical brain volumes in typically developing fetuses scanned longitudinally in the third trimester. The authors hypothesized that reduced placental oxygenation would be associated with relatively smaller cortical volumes compared with subcortical regions.
The study was supported by grants from Brain Canada, The Children’s Health Research Institute, Canadian Institutes of Health Research, BrainsCAN and the Molly Towell Perinatal Research Foundation.