Laminar Architecture and Morphometry of Developing Human Fetal Cerebellum

Background: One of the organs in the human fetus that starts to differentiate extremely early and keeps doing so throughout the postnatal period is the cerebellum. The goal of this study was to create a nomogram using the chronological events that were occurring and the relationship with progressing gestational age. Granule cells and Purkinje cells play a crucial role in the normal development of the cerebellum. Any disruption at the cellular level can lead to abnormal migration of these cells, potentially resulting in hypoplasia of the cerebellar vermis. Methodology: Tissue specimens from 60 human fetuses were studied for histological changes after being grouped into four from 13th week to 32nd week. Fetuses with any neurological deficit were excluded from the study. Different layers were identified, and the thickness of each layer was noted. Results: The first two groups had three layers, but the composition was different in both. The marginal and mantle layers in the second group disappeared completely. The third group showed presence of five layers, with addition of lamina dissecans, appearing for a transient period. The fourth group had four layers. The thickness of external granular layer and internal granular layer (IGL) increased throughout, except that the IGL made an appearance from the second group only. Lamina dissecans appeared, causing a significant shift between 23 and 27 weeks. The fetus has a four-layered structure near term, with an external granular layer persisting throughout the early postnatal stage of life. Progression of pregnancy was positively connected with the molecular and Purkinje cell layer (PCL) thickness. Conclusion: Progression of pregnancy was positively connected with the molecular and PCL thickness. Age determination and neuropsychiatric disorders of the developing fetus may benefit from such a link.