PRENATAL DEVELOPMENT OF THE HUMAN LIVER THROUGH THE LENS OF SINGLE-CELL TECHNOLOGIES

Background: Prenatal liver development integrates hepatobiliary differentiation, vascular and stromal assembly, and fetal hematopoiesis. Methods: This structured narrative review evaluated peer-reviewed human embryonic and fetal-liver studies identified in PubMed/MEDLINE and PubMed Central through July 2026. Claims were weighted by donor-level replication, spatial or protein corroboration, and functional validation. Results: Single-cell and spatial atlases consistently resolve epithelial, endothelial, mesenchymal, stromal, hematopoietic, and immune compartments and place selected states within ductal-plate, vascular, and hematopoietic niches. The review examines hepatobiliary hybrid progenitors, ID3-positive hepatoblast candidates, stellate-endothelial transitional states, and function-associated fetal HSPC populations. Agreement is strongest for major compartments and broad maturation patterns, but weaker for rare states, lineage direction, and inferred cell-cell signaling. Ambient RNA, dissociation bias, donor composition, and integration strategy can materially alter marker and pathway estimates. Conclusion: These atlases provide a robust framework for prenatal liver biology, but most trajectories and communication networks remain inferential. Progress requires donor-level replication, standardized developmental-age metadata, orthogonal spatial or protein confirmation, causal perturbation, and public release of reusable data.