RESUMEN
OBJECTIVE: Despite its widespread use, in vitro fertilization (IVF) outcomes are challenged by implantation failure, largely due to factors such as embryo quality and endometrial receptivity. In this study, we investigated the clinical effect of office hysteroscopy (OH) on the subsequent frozen-thawed embryo transfer (FET) in infertile women who experienced a failed IVF-embryo transfer (IVF-ET) cycle. METHODS: We included 577 infertile women who underwent OH because of a history of failed ET between October 2019 and September 2021. During OH, visible endometrial polyps (EPs) were diagnosed and removed by curette or biopsy forceps; chronic endometritis (CE) was diagnosed by histopathology and immunohistochemistry and treated with oral doxycycline (0.2 g/d) for 14 days. According to the hysteroscopic findings and endometrial pathology with immunohistochemistry, patients were divided into three groups: group A (n = 161) had CE with or without EPs, group B (n = 156) had EPs only, and group C (n = 260) had no CE or EPs. RESULTS: In the following FET cycle, the implantation rates were 47%, 51%, and 45% (P = 0.411); the clinical pregnancy rates were 56%, 62%, and 55% (P = 0.436); the live birth rates were 45%, 51%, and 42% (P = 0.205); and the miscarriage rates were 18%, 16%, and 22% (P = 0.497) in groups A, B, and C, respectively. There were no significant differences among groups (P > 0.05). CONCLUSION: OH is helpful for diagnosis and treatment of abnormal intrauterine environment in women with a failed IVF cycle and further improves their pregnancy outcome in the following FET.
RESUMEN
The prevalence of endometriosis is approximately 10% in women of reproductive age, and 30-50% of women with endometriosis are infertile. Metformin has been reported to inhibit the growth of ectopic lesions in endometriosis. However, its effect on the eutopic endometrium of endometriosis is unknown. This study aimed to identify whether metformin affects endometrial receptivity in infertile women with minimal/mild endometriosis. We enrolled 10 infertile women who were diagnosed with minimal/mild endometriosis through laparoscopy. Paired endometrial tissues of the secretory phase from participants were collected during surgery and after 2 months of metformin treatment (n = 5) or no medical treatment (n = 5). Protein expression profiles of the paired endometrium were detected by proteomics and compared using the self-control method (2 months later vs. in surgery). Proteomics data revealed six proteins associated with endometrial receptivity among the significantly upregulated proteins after metformin treatment (fold change > 1.5, P < 0.05). Insulin-like growth factor binding protein 7 (IGFBP-7) showed the most robust increase in these six endometrial receptivity-related proteins (fold change: 8.668, P < 0.05), while there was no significant change in the controls (fold change: 1.906, P > 0.05). The upregulation of IGFBP-7 has been validated through target proteomics, immunohistochemistry, and further demonstrated in endometriosis mouse models induced by autotransplantation. This study revealed that metformin upregulated the expression of IGFBP-7 in the endometrium of human and mouse models of endometriosis. Metformin potentially affects endometrial receptivity of minimal/mild endometriosis by improving the expression of the endometrial receptivity marker IGFBP-7.