Inside the womb: New method to measure how baby brains develop

The human brain undergoes rapid changes during pregnancy, with early growth influencing cognitive and developmental outcomes after birth. Early brain size has been linked to later academic abilities, while abnormal growth patterns are associated with risks for psychiatric disorders.

Much of our past understanding has relied on post-mortem studies, which fail to capture the full spectrum of normal development. In this study, the researchers created a tool that can automatically analyze images of the babies' brains while still in the womb.

The study
Since a baby's skull grows because of the slight pressure from the growing brain inside, the intracranial volume can be used as a measurement of brain growth.

They automated the measurement of intracranial volume, a reliable marker of brain size using 3D ultrasound, combined with artificial intelligence analysis.

To train the AI, they used 168 high-quality ultrasound images, enhancing the training process by introducing slight variations in the data to make the model more flexible.

The model was then tested on thousands of ultrasound scans from the YOUth Baby and Child cohort, which includes data from over 2,200 pregnancies, with measurements taken at 20 and 30 weeks of gestation.

The final model produced reliable and precise measurements of brain size, without the need for time-consuming manual checks. It automatically processed over 43,000 ultrasounds, identifying clear brain data and estimating brain growth for 18% of the scans.

The study revealed sex differences in brain growth as early as 20 weeks of gestation. Boys exhibited larger brain volumes than girls but also showed faster growth during the critical period between 20 and 30 weeks of pregnancy.

Opportunities for Clinical and Scientific Impact
This approach is groundbreaking because it enables large-scale studies of fetal brain development and provides insights into how early differences may influence future cognitive and developmental outcomes.

With further refinements, this tool could help researchers answer important questions about prenatal brain growth and its impact on health and behavior later in life.

Early detection of atypical growth patterns could help identify risks for neurodevelopmental disorders even before the baby is born.

About the scientific paper:

First author: Sonja M. C. de Zwarte, The Netherlands
Published in: Human Brain Mapping, December 2024
Link to paper: https://onlinelibrary.wiley.com/doi/10.1002/hbm.70058