The oviduct: a key to unlocking reproductive science

Despite significant advances, assisted reproductive techniques (ARTs) remain suboptimal due to challenges linked to embryo development and quality, often attributed to the epigenetic reprogramming process and environmental factors. The aim of this review is to summarize the function of the oviduct, the organ where fertilization takes place. This organ plays a crucial but often overlooked role in natural fertilization, where it selectively allows only a few sperm to reach the egg, contrary to what happens in in vitro conditions, where oocytes are exposed many sperm, without this always resulting in fertilization. The oviduct environment is vital for fertilization, since it creates a reservoir for sperm, extending their viability and readiness for fertilization. In addition, the environment provided by this organ is optimal for the early stages of embryo development. Interactions between embryos and oviduct cells affect gene expression, improving embryo quality. Mimicking the conditions of the oviduct, by using oviductal fluid in culture media, for example, or developing advanced 3D cultures and microfluidic systems, can improve ART outcomes and embryo quality. In conclusion, the oviduct is essential for creating the optimal environment for fertilization and embryo development. Replicating its conditions can enhance ART success and the health of the offspring, highlighting its importance in reproductive processes. KEY WORDS: Oviduct, ART, reproduction.