Association of Gestational Age at Birth With Brain Morphometry

Gestational age (GA) at birth is an important factor in child health and neurodevelopment. Yet, few studies have evaluated the associations between GA and brain morphometry. The aim of this study was to explore the association between GA and brain structures of children aged 10 years. This was a prospective, population-based, cohort study out of Rotterdam, the Netherlands, involving women with singleton pregnancies who gave birth between 2002 and 2006. The offspring resulting from these births were invited to undergo neuroimaging at the age of 10. Data analysis was performed between 2019 and 2020. Ultrasonography of crown-rump length and biparietal diameter were used to assess GA. Brain images of the children were used to measure global and regional volumes, including total brain, cerebral and cerebellar gray and white matter, and subcortical gray matter volumes. Cortical thickness and surface area as well as neocortical folding were also measured. A total of 3079 children (1546 [50.2%] female) were included in the analysis. Positive associations were observed between GA and global and regional brain volumes. Longer duration of gestation was associated with larger brain volumes (4.5 cm(3)/ wk; 95% confidence interval [CI], 2.7-6.3 cm(3)/wk), as well as larger volumes of cerebral gray matter (2.8 cm(3)/wk; 95% CI, 1.8-3.7 cm(3)/wk), cerebral white matter (1.2 cm(3)/wk; 95% CI, 0.3-2.0 cm(3)/wk), cerebellar gray matter (0.4 cm(3)/wk; 95% CI, 0.2-0.5 cm(3)/wk), cerebellar white matter (0.1 cm(3)/wk; 95% CI, 0.1-0.2 cm(3)/wk), and subcortical gray matter (0.2 cm(3)/wk; 95% CI, 0.1-0.2 cm(3)/wk). When restricted to a sample of children born at term (between 37 and 42 weeks), these associations, except for cerebellar gray matter, remained consistent (4.5 cm(3)/wk; 95% CI, 1.8-7.7 cm(3)/wk). Positive associations were also observed between GA and cerebral cortex morphometry: longer duration of gestation was associated with larger cortical surface area and gyrification/folding. When restricted to the sample of children born at term, the results were similar. Longer gestational duration was associated with larger global and regional brain volumes, cortical surface area, and gyrification. These observations suggest that the last few weeks of pregnancy are important for long-term neurodevelopment.