The Impact of Uterine Disorders on Embryo Implantation and Early Survival: From Molecular Insights to Clinical Evidence.

Background: Embryo implantation and early survival in a synchronized, receptive endometrium are critical for establishing a successful pregnancy, but uterine pathologies can present challenges to reproductive success by significantly impacting this complex process.

Objectives: The purpose of this review was to analyze the impact of uterine pathologies on embryo implantation, early embryo survival, and finally on the development of infertility, with references to reproductive outcomes and the main evidence related to therapeutic strategies.

Methods: The relevant publications were identified after queries of the following sources: PubMed, Google Scholar, Web of Science, and publishers' databases, complemented by a cross-check of the reference lists. We used a combination of the search terms "uterine pathology," "infertility," "embryo implantation," and "embryo survival" with terms relevant to the topic of each paragraph, such as "endometrial polyps (EPs)," "leiomyoma," "uterine malformations," "adenomyosis," and "intrauterine adhesions (IUAs)."

Outcome: All articles describing the influence of each uterine pathology on embryo implantation/early survival were included, with a focus on the role of EPs, leiomyomas, uterine malformations, adenomyosis, and IUAs.

Conclusions and outlook: The exact influence of uterine diseases on the uterine-embryo crosstalk is unknown. Nevertheless, numerous molecular mechanisms have been proposed to explain some of the underlying processes. Tailored treatments for each specific disease may improve the endometrial milieu and, thus, reproductive outcomes. Future studies should aim to further understand the underlying molecular phenomena driving the development of these pathologies, how they may disrupt early embryo life stages, and the exact benefit of medical and surgical treatments on embryo survival.