Gestational age and neonatal brain microstructure in term born infants: a birth cohort study.

Birit F P Broekman,Anqi Qiu,Michael J Meaney,Anne Rifkin-Graboi,Marielle V Fortier,Yap-Seng Chong,Peter D Gluckman,Yue Li,Seang Mei Saw,Kenneth Kwek,Changqing Wang,Nouchine Hadjikhani

doi:10.1371/journal.pone.0115229

Abstract

ObjectiveUnderstanding healthy brain development in utero is crucial in order to detect abnormal developmental trajectories due to developmental disorders. However, in most studies neuroimaging was done after a significant postnatal period, and in those studies that performed neuroimaging on fetuses, the quality of data has been affected due to complications of scanning during pregnancy. To understand healthy brain development between 37–41 weeks of gestational age, our study assessed the in utero growth of the brain in healthy term born babies with DTI scanning soon after birth.MethodsA cohort of 93 infants recruited from maternity hospitals in Singapore underwent diffusion tensor imaging between 5 to 17 days after birth. We did a cross-sectional examination of white matter microstructure of the brain among healthy term infants as a function of gestational age via voxel-based analysis on fractional anisotropy.ResultsGreater gestational age at birth in term infants was associated with larger fractional anisotropy values in early developing brain regions, when corrected for age at scan. Specifically, it was associated with a cluster located at the corpus callosum (corrected p<0.001), as well as another cluster spanning areas of the anterior corona radiata, anterior limb of internal capsule, and external capsule (corrected p<0.001).ConclusionsOur findings show variation in brain maturation associated with gestational age amongst ‘term’ infants, with increased brain maturation when born with a relatively higher gestational age in comparison to those infants born with a relatively younger gestational age. Future studies should explore if these differences in brain maturation between 37 and 41 weeks of gestational age will persist over time due to development outside the womb.

Highlights

Understanding healthy fetal brain development is essential to be able to detect abnormal developmental trajectories due to developmental disorders [1]
Microstructure development is best measured by diffusion tensor imaging (DTI) [10], with white matter maturation characterized by increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD) [11]
The Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort consisted of pregnant Asian women attending the first trimester antenatal ultrasound scan clinic at the National University Hospital (NUH) and KK Women’s and Children’s Hospital (KKH) in Singapore, which are the two major maternity hospitals in Singapore

Summary

Introduction

Understanding healthy fetal brain development is essential to be able to detect abnormal developmental trajectories due to developmental disorders [1]. A recent study showed the extraordinary rates of structural growth in the very early postnatal period [13]. As such imaging after a significant postnatal period will not inform us much about the in utero brain development and it remains unclear if altered neuroconnectivitity emerges prenatally [14]. During the third trimester growth and neurogenesis of the fetal brain increase significantly, the direct effects of a relatively younger gestational age at birth in healthy term infants on these processes are not yet well understood [14, 17]

Methods

Results

Conclusion