Resumen:
In this article, we present a review about the use of the term "preembryo" in the scientific literature as well as Bioethics from its origin, back in June 1979, to the end of the year 2014. We analyze their evolution along the time comparing with other terms commonly used in embryology. Also, we show the relevant journals in which this term appears, (offering the impact index within their specific field), and the authors who use it the most. The term "preembryo" arose in the scientific literature in 1979, remaining for about 6 years without reappearing in the scientific literature. Then, after an increase of articles, that covers the 90's decade, began to decrease its use without having disappeared altogether. Our study also shows that the use of the word "preembryo" has not increased with the passage of time; on the contrary, it is becoming less used in the biomedical literature. This does not occur with other terms that name the embryo before implantation, which have not ceased to increase during these years, both referring to the human species and other animal species. Finally, the term "pre-embryo" appears very little in journals related to the reproduction biology area, but it does so in obstetrics and gynecology, where many articles on assisted reproduction are published. Our findings suggest that, instead of replacing classical embryological terms, the word "preembryo" does not seem to affect the use of them. Likewise, this word has a hypertrophied use in humans without an apparent reason, which would support the artificial nature of this term. Finally, the term "pre-embryo" appears very little in journals of reproduction biology area, but it does so in obstetrics and gynecology, where many articles on assisted reproduction are published. In conclusion, instead of substituting classical embryological terms, the word "pre-embryo" does not seem to affect the use of them and in the current discussions about the human condition of the embryo this term is no longer used.