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Updated: May 24, 2026
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Neonatal neurobehavior and diffusion MRI changes in brain reorganization due to intrauterine growth restriction in a
Elisenda Eixarch1, Dafnis Batalle, Miriam Illa
1Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia, Hospital Clinic, Barcelona, Spain.
Insights
Intrauterine growth restriction (IUGR) causes significant neurodevelopmental issues and brain reorganization evident at birth. Diffusion MRI reveals these changes, offering potential for early intervention in affected newborns.
Area of Science:
- Neuroscience
- Developmental Biology
- Medical Imaging
Background:
- Intrauterine growth restriction (IUGR) affects 5-10% of newborns, increasing the risk of abnormal neurodevelopment.
- The brain reorganization patterns in IUGR fetuses are not well understood.
- A rabbit model was developed for studying IUGR's effects on the fetal brain.
Purpose of the Study:
- To describe the pattern of fetal brain reorganization caused by IUGR.
- To identify functional correlates of this brain reorganization.
- To utilize diffusion MRI for characterizing IUGR-induced brain changes.
Main Methods:
- IUGR was induced in fetal rabbits by reducing uteroplacental blood flow.
- Neonatal neurobehavioral tests were performed at postnatal day 1.
- High-resolution diffusion MRI was used to analyze brain structure.
- Voxel-based analysis identified differences in diffusion tensor imaging parameters.
Main Results:
- IUGR rabbits showed significantly impaired neurobehavioral performance.
- Diffusion MRI revealed widespread fractional anisotropy (FA) differences in gray and white matter regions.
- Specific brain regions affected include the cortex, hippocampus, putamen, and white matter tracts.
- Regional FA changes correlated with poorer neurobehavioral outcomes.
Conclusions:
- IUGR is linked to complex brain reorganization detectable at birth.
- These findings suggest opportunities for early therapeutic interventions.
- Diffusion MRI serves as a valuable tool for monitoring brain changes in fetal conditions like IUGR.
Background:
Intrauterine growth restriction (IUGR) affects 5-10% of all newborns and is associated with a high risk of abnormal neurodevelopment. The timing and patterns of brain reorganization underlying IUGR are poorly documented. We developed a rabbit model of IUGR allowing neonatal neurobehavioral assessment and high resolution brain diffusion magnetic resonance imaging (MRI). The aim of the study was to describe the pattern and functional correlates of fetal brain reorganization induced by IUGR.
Methodology/Principal Findings:
IUGR was induced in 10 New Zealand fetal rabbits by ligation of 40-50% of uteroplacental vessels in one horn at 25 days of gestation. Ten contralateral horn fetuses were used as controls. Cesarean section was performed at 30 days (term 31 days). At postnatal day +1, neonates were assessed by validated neurobehavioral tests including evaluation of tone, spontaneous locomotion, reflex motor activity, motor responses to olfactory stimuli, and coordination of suck and swallow. Subsequently, brains were collected and fixed and MRI was performed using a high resolution acquisition scheme. Global and regional (manual delineation and voxel based analysis) diffusion tensor imaging parameters were analyzed. IUGR was associated with significantly poorer neurobehavioral performance in most domains. Voxel based analysis revealed fractional anisotropy (FA) differences in multiple brain regions of gray and white matter, including frontal, insular, occipital and temporal cortex, hippocampus, putamen, thalamus, claustrum, medial septal nucleus, anterior commissure, internal capsule, fimbria of hippocampus, medial lemniscus and olfactory tract. Regional FA changes were correlated with poorer outcome in neurobehavioral tests.
Conclusions:
IUGR is associated with a complex pattern of brain reorganization already at birth, which may open opportunities for early intervention. Diffusion MRI can offer suitable imaging biomarkers to characterize and monitor brain reorganization due to fetal diseases.
