Human brain R2* transitions across birth from the womb to early infancy.

Area of Science:

• Neuroscience
• Developmental Biology
• Medical Imaging

Background:

• Iron is crucial for early brain development, impacting myelination and neurotransmitter synthesis.
• The perinatal period involves significant brain adaptation to extrauterine stimuli and metabolic demands.
• Previous studies lacked the spatiotemporal resolution to detail brain iron changes around birth.

Purpose of the Study:

• To map longitudinal brain iron growth trajectories using R2* estimation across the perinatal period.
• To investigate regional differences in brain iron development.
• To examine the influence of sex, gestational age, and birth weight on these trajectories.

Main Methods:

• Utilized a longitudinal cohort of 147 multi-echo MRI scans from 25 to 60 post-conceptual gestational weeks.
• Applied R2* estimation to map brain iron concentration.
• Analyzed developmental trajectories across fetal, newborn, and neonatal periods.

Main Results:

• Parietal and superior temporal regions showed predominantly linear iron growth trajectories.
• Occipital cortex, temporal pole, inferior temporal, and frontal regions exhibited non-linear growth patterns.
• Growth rates for non-linear trajectories peaked around 40 weeks, emphasizing the birth transition window.

Conclusions:

• This study provides the first longitudinal R2* development insights across birth.
• Distinct regional brain iron growth patterns were uncovered, potentially aligning with neurodevelopmental phases.
• The findings highlight the critical role of the perinatal period for brain iron accretion and adaptation.