Abstract

Purpose Recurrent spontaneous abortion (RSA) endangers women's health with a 5%–15% clinical incidence. Exploring the diagnostic capability of miR-199a-5p in RSA and its role in the function of trophoblast cells. Methods qRT-PCR detected miR-199a-5p and E2F3 expression; correlation and Logistic regression analyses clarified their clinical relevance. Western blot, dual-luciferase reporter assay, CCK-8, and Transwell assays were used to verify the targeting relationship between miR-199a-5p and E2F3, and their regulatory effects on trophoblast biological functions and EMT. Results miR-199a-5p level in patients with RSA is significantly decreased, and it has good diagnostic efficacy (AUC = 0.804, 95% CI: 0.724–0.883, sensitivity: 76.2%, specificity: 79.6%). Furthermore, a multivariate model combining miR-199a-5p with clinical parameters achieved an AUC of 0.903, with 85.2% sensitivity and 84.1% specificity. miR-199a-5p is an independent risk factor for RSA, negatively correlated with E2F3 and inflammatory markers, and is positively correlated with reproductive hormones. miR-199a-5p directly targets E2F3. Overexpression of miR-199a-5p promotes the function of trophoblast cells, while overexpression of E2F3 reverses these effects. Conclusions miR-199a-5p shows promise as a diagnostic marker for RSA, modulates trophoblast functions and EMT by targeting E2F3, participates in RSA progression and provides a novel therapeutic target.