Objective: To assess the effect of hysteroscopic polypectomy on the in vitro fertilization (IVF) results in infertile women with at least one prior negative IVF outcome. Methods: This retrospective cohort study included women who had attended the “2nd Department of Obstetrics and Gynecology of the National and Kapodistrian University of Athens” and “Iaso” Maternity Hospital from October 2019 to January 2023 for infertility treatment. The medical records of 345 women aged 18–45 years old without abnormal findings in hysterosalpingography (HSG) and with at least one previous failed IVF procedure were analyzed. The male factor was excluded, as well as a prior hysteroscopic removal of polyps. In 67 women, polyps were suspected during initial two-dimensional ultrasound (2D-US) examination. The final sample of the study comprised 40 patients, in which endometrial polyps were removed by hysteroscopy with the use of resectoscope. All patients underwent ovarian stimulation and IVF in the consecutive cycle using a short GnRh antagonist protocol. Main Results: After hysteroscopic polypectomy, 29 (72.5%) out of 40 patients had a positive pregnancy result: 26 (65%) clinical and 3 (7.5%) biochemical pregnancies were documented. There was a statistically significant difference between the number of clinical pregnancies before and after polypectomy (p < 0.001), as well as between the total number of pregnancies (p < 0.001). Secondary Results: Women with positive outcome were significantly younger and had significantly lower FSH levels (p < 0.007). They also had significantly higher AMH (p < 0.009) and peak estradiol levels (p < 0.013) and yielded more M II oocytes (p < 0.009) and embryos (p < 0.002). Conclusions: Hysteroscopic polypectomy in women with a suspected endometrial polyp using 2D ultrasound and a history of prior failed IVF attempt improves IVF outcomes in terms of the clinical and total number of pregnancies.

Successful embryo implantation requires dynamic, bidirectional communication between a developmentally competent blastocyst and a receptive endometrium, integrating hormonal, molecular, and immunologic signals. Increasing evidence indicates that endometrial receptivity is critically dependent on a specialized immune microenvironment that supports trophoblast invasion while maintaining maternal tolerance. This review synthesizes current knowledge on the immunologic regulation of implantation, with emphasis on uterine natural killer (uNK) cells, regulatory T cells (Tregs), macrophages, dendritic cells, and cytokine networks. We further examine intracellular signaling pathways—including JAK/STAT, PI3K/AKT, NF-κB, and MAPK—that integrate immune and decidual responses. The bidirectional embryo–endometrium dialogue is explored through embryo-derived mediators such as human chorionic gonadotropin (hCG), cytokines, growth factors, and extracellular vesicles. The endometrium is increasingly recognized as a biosensor of embryo quality, selectively supporting viable embryos. Disruption of this complex communication network is implicated in recurrent implantation failure and early pregnancy loss. Despite substantial mechanistic advances, clinical translation remains limited. Emerging strategies, including immune profiling, microbiome modulation, and extracellular vesicle-based diagnostics, hold promise for precision reproductive medicine.

Successful embryo implantation requires dynamic, bidirectional communication between a developmentally competent blastocyst and a receptive endometrium, integrating hormonal, molecular, and immunologic signals. Increasing evidence indicates that endometrial receptivity is critically dependent on a specialized immune microenvironment that supports trophoblast invasion while maintaining maternal tolerance. This review synthesizes current knowledge on the immunologic regulation of implantation, with emphasis on uterine natural killer (uNK) cells, regulatory T cells (Tregs), macrophages, dendritic cells, and cytokine networks. We further examine intracellular signaling pathways—including JAK/STAT, PI3K/AKT, NF-κB, and MAPK—that integrate immune and decidual responses. The bidirectional embryo–endometrium dialogue is explored through embryo-derived mediators such as human chorionic gonadotropin (hCG), cytokines, growth factors, and extracellular vesicles. The endometrium is increasingly recognized as a biosensor of embryo quality, selectively supporting viable embryos. Disruption of this complex communication network is implicated in recurrent implantation failure and early pregnancy loss. Despite substantial mechanistic advances, clinical translation remains limited. Emerging strategies, including immune profiling, microbiome modulation, and extracellular vesicle-based diagnostics, hold promise for precision reproductive medicine.