Developing reliable models that capture the complexity of maternal– embryonic interactions and implantation is essential for deepening our understanding of early embryonic development as well as the underlying mechanisms of reproductive disorders. Conventional two-dimensional (2D) culture systems, however, fall short in accurately replicating the dynamic and multilayered in vivo microenvironment. In contrast, three-dimensional (3D) organoid technologies have recently emerged as a transformative approach, offering structurally and functionally relevant platforms that better reflect physiological conditions. This review highlights the latest strategies, innovations, and methodological advances in employing 3D organoids to model maternal–embryonic communication and implantation processes. It also outlines their growing potential in research applications and personalized medicine, particularly within the context of assisted reproductive technologies. Furthermore, the review discusses future directions for organoid-based studies from the endometrium, oviduct, ovary, testis, and epididymis have been established, their integration with gametes and embryos marks a new frontier. Cross-species work, especially your pioneering studies on endometrial organoids and lacunoids/cystoids, opens translational opportunities for understanding maternal–embryonic crosstalk, implantation biology, and fertility disorders. The review will discuss current advances, technical challenges, and future directions toward interconnected organoid systems (organoid-on-chip).

In the last 10 years, porcine somatic cell nuclear transfer to generate transgenic pig has been performed tremendous development with introduction and knockout of many genes. However, efficiency of porcine somatic cell nuclear transfer is still low and embryo transfer (ET) is one of important step for production efficiency. In porcine ET for production of transgenic cloned pig, we can consider many of points to increase production rates. In respect of seasonality and weather, porcine ET usually is not performed in summer and winter. Cloned transgenic embryos must be transferred into reproductive tracts of recipients where embryos are located after natural fertilization with similar estrous cycle. If cloned embryos with 2∼4 cell stage are transferred, they must be transferred into oviducts in periovulatory stage. Number and deposition sites of transferred cloned embryos are important. And we must compare the methods of ET between surgical and non-surgical ones in respect of production efficiency. Sow recipients after natural estrus is most preferred recipients however its cost is must be considered. Here we will review many of current studies about porcine embryo transfer to increase production efficiency of transgenic pigs and strategies for further studies.