The role of dendritic cells in recurrent pregnancy loss.

Recurrent pregnancy loss (RPL), defined as ≥ 2 consecutive losses, remains a significant clinical challenge with complex immunological underpinnings. While immune dysfunction underpins RPL, dendritic cells (DCs) emerge as central regulators of maternal-fetal tolerance. This review comprehensively explores the multifaceted roles of DC subsets at the maternal-fetal interface, including their contribution to immune tolerance, angiogenesis, placental development, and bidirectional interactions with trophoblasts and natural killer (NK) cells. We detail specific DC alterations in RPL, encompassing phenotypic shifts, functional defects, and disrupted DC-NK cell crosstalk, linking these changes to pregnancy loss risk. Emerging evidence highlights therapeutic strategies targeting DCs, such as tolerogenic DC vaccines and interventions modulating trophoblast MHC antigen presentation, alongside established immunomodulation, to restore immune balance. Underlying mechanisms like systemic inflammation impacting endometrial DCs are also discussed. By synthesizing current literature and controversies, this review elucidates the critical, yet complex, role of DC heterogeneity and function in RPL pathogenesis and discusses innovative interventions aimed at improving pregnancy outcomes.