Related Experiment Video
Updated: Mar 10, 2026
A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis
Published on: January 7, 2018
Third Trimester Brain Growth in Preterm Infants Compared With In Utero Healthy Fetuses
Marine Bouyssi-Kobar1,2, Adré J du Plessis3, Robert McCarter4
1The Developing Brain Research Laboratory, Departments of Diagnostic Imaging and Radiology.
Insights
Preterm infants show impaired brain growth during the third trimester, even without visible brain injury. Risk factors like sepsis and oxygen support worsen reduced brain volumes in these vulnerable infants.
Area of Science:
- Neonatal neuroscience
- Fetal development research
- Pediatric brain imaging
Background:
- Preterm infants often exhibit impaired brain development compared to term infants.
- The precise timing and progression of impaired brain development during the third trimester remain unclear.
- Understanding these early developmental changes is crucial for timely intervention.
Purpose of the Study:
- To compare third-trimester brain volumes and growth trajectories in preterm infants versus healthy fetuses.
- To identify clinical risk factors associated with altered brain volumes in preterm infants during the third trimester.
Main Methods:
- Prospective recruitment of preterm infants (<32 weeks GA, <1500g) without structural brain injury and healthy fetuses.
- Anatomic T2-weighted MRI scans were acquired for brain parcellation.
- Analysis included cerebrum, cerebellum, brainstem, and intracranial cavity volumes.
Main Results:
- Reduced brain volumes and slower growth trajectories were observed in preterm infants compared to controls across all measured brain regions.
- Clinical factors linked to reduced brain volumes included dexamethasone treatment, extra-axial blood, sepsis, and oxygen support duration.
- These findings were present in the absence of detectable parenchymal injury on conventional MRI.
Conclusions:
- Preterm infants experience impaired global and regional brain growth during the third trimester, irrespective of detectable MRI injury.
- Early brain growth deficits in preterm infants highlight the vulnerability of the developing brain in the neonatal intensive care unit environment.
Background And Objectives:
Compared with term infants, preterm infants have impaired brain development at term-equivalent age, even in the absence of structural brain injury. However, details regarding the onset and progression of impaired preterm brain development over the third trimester are unknown. Our primary objective was to compare third-trimester brain volumes and brain growth trajectories in ex utero preterm infants without structural brain injury and in healthy in utero fetuses. As a secondary objective, we examined risk factors associated with brain volumes in preterm infants over the third-trimester postconception.
Methods:
Preterm infants born before 32 weeks of gestational age (GA) and weighing <1500 g with no evidence of structural brain injury on conventional MRI and healthy pregnant women were prospectively recruited. Anatomic T2-weighted brain images of preterm infants and healthy fetuses were parcellated into the following regions: cerebrum, cerebellum, brainstem, and intracranial cavity.
Results:
We studied 205 participants (75 preterm infants and 130 healthy control fetuses) between 27 and 39 weeks' GA. Third-trimester brain volumes were reduced and brain growth trajectories were slower in the ex utero preterm group compared with the in utero healthy fetuses in the cerebrum, cerebellum, brainstem, and intracranial cavity. Clinical risk factors associated with reduced brain volumes included dexamethasone treatment, the presence of extra-axial blood on brain MRI, confirmed sepsis, and duration of oxygen support.
Conclusions:
These preterm infants exhibited impaired third-trimester global and regional brain growth in the absence of cerebral/cerebellar parenchymal injury detected by using conventional MRI.
