IMPORTANCE: Human trophoblast development is essential for implantation, placental formation, and pregnancy success yet has historically been challenging to study because of limited access to early human tissues and the inadequacy of animal models to capture human-specific features. Advances in stem cell and organoid technologies have now provided tractable, renewable platforms that more faithfully reproduce human trophoblast biology.
OBJECTIVE: To summarize the development of human trophoblast organoids, outline their overall fidelity and utility for dissecting trophoblast lineage specification, and discuss their emerging role as translational tools for understanding placental development and pathologies specific to pregnancy.
EVIDENCE REVIEW: We reviewed primary literature related to primary trophoblast model systems, establishment of epithelial organoid systems, and trophoblast stem cells and organoid cultures (2018-2025) and subsequent studies that benchmarked organoids against in vivo trophoblast populations using transcriptomic, epigenetic, and functional assays. Particular attention was given to work characterizing trophoblast lineage fidelity, refinements in culture conditions, and applications of trophoblast organoids to model infection.
FINDINGS: First-trimester trophoblast organoids recapitulate villous cytotrophoblast progenitors and their capacity to generate both syncytiotrophoblast and invasive extravillous trophoblast lineages, with refinements now enabling more physiologic orientation and maturation cell states. Term and pluripotent stem cell-derived organoid systems expand the developmental spectrum, although each platform carries unique strengths and limitations. These models are beginning to yield insight into pregnancy-relevant conditions, including viral pathogenesis, impaired trophoblast invasion, and disease-associated epigenetic memory. Emerging work demonstrates that trophoblast organoids can serve as patient-specific models for interrogating placental dysfunction.
CONCLUSION AND RELEVANCE: Trophoblast organoids represent state-of-the-art in vitro systems for studying human trophoblast development, bridging a critical gap between animal models and primary tissue culture systems. By enabling detailed analysis of lineage specification and patient-specific pathophysiology, they hold great promise for advancing both fundamental discovery and translational applications in reproductive medicine, with potential future use in clinical contexts such as fertility assessment and in vitro fertilization.
