Altered Expression of Circulating miR-223-3p in Patients with Idiopathic Recurrent Pregnancy Loss: A Case and Control Study

Background: Circulating microRNAs (miRNAs or miRs) are key regulators of a wide array of biological processes that aberrantly express under physiological as well as pathological conditions. This study aims to determine whether altered expression of circulating miR-223-3p in plasma is associated with an increased risk of idiopathic recurrent pregnancy loss (iRPL), and if it could be a novel non-invasive biomarker for diagnosis of iRPL. Materials and Methods: In this case and control study, Plasma samples were obtained from 60 women with a history of >= 2 consecutive miscarriages and 60 women with at least one full-term pregnancy and no history of miscarriage. The samples were used to assess the expression of circulating miR-223-3p by quantitative real-time polymerase chain reaction (qPCR) and determine the correlation between patient clinico-demographic parameters and miR-223-3p expression levels. We used receiver operating characteristic (ROC) curve analysis to evaluate the diagnostic accuracy of miR-223-3p for the diagnosis of iRPL. Results: There was significant up-regulation in miR-223-3p expression in patients with iRPL compared with healthy controls (P=0.002). No significant correlation was found between the expression level of miR-223-3p and the number of miscarriages in iRPL patients (P=0.344). ROC curve analysis revealed that the area under the curve (AUC) value for miR-223-3p was 0.658 [95% confidence interval (95% CI): 0.5590.757, P=0.002). Conclusion: These results suggest that a higher expression level of circulating miR-223-3p may be closely related with the increased risk of iRPL and possibly serve as a promising non-invasive diagnostic biomarker for iRPL.