Objective To investigate the expression level and clinical significance of circular RNAs(circRNAs)in serum extracellular vesicles(EVs)of patients with recurrent spontaneous abortion(RSA).Methods The serum samples from 3 RSA patients and 3 nor-mal pregnant women(controls)visited our hospital from May 2021 to March 2023 were collected and the gene expression profiling chips were used to screen for differentially expressed circRNAs in serum EVs.Ten RSA patients and 10 normal pregnant women were enrolled in a training set and 80 RSA patients and 64 normal pregnant women were enrolled in a validation set.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the levels of differentially expressed circRNAs between the two groups.The predictive value of differentially expressed circRNAs for RSA was evaluated by the receiver operating characteristic(ROC)curve.Results A total of 57 563 circRNAs in serum EVs were detected by the gene expression profiling chips.Compared with the control group,3 516 circRNAs were differentially expressed in RSA patients,including 2 377 up-regulated and 1 139 down-regulated.The de-tection results of qRT-PCR in the training set and validation set showed that the expression levels of hsa＿circ＿0054403 in serum EVs of RSA patients(2.07[1.00,6.68])was significantly higher than that in the control group(1.00[0.42,1.46],U=1 239,P＜0.01),while those of hsa＿circ＿0020897(0.33[0.11,1.40]vs 1.00[0.46,3.66],U=1 712,P＜0.01)and hsa＿circ＿0072745(0.49[0.22,1.60]vs 1.00[0.51,7.93],U=1 714,P＜0.01)were significantly lower than that in the control group.The ROC curve showed that the hsa＿circ＿0054403,hsa＿circ＿0020897,and hsa＿circ＿0072745 in serum EVs had high predictive value for RSA.Their AUCROC were 0.758,0.666,and 0.664,respectively,and the corresponding sensitivity and specificity were 47.5% and 100.0%,50.0% and 81.2%,and 62.5% and 70.3%,respectively.When the three circRNAs were combined,it's AUCROC,sensitivity,and specificity were 0.842,73.7%,and 79.7%,respectively.Conclusion The hsa＿circ＿0054403,hsa＿circ＿0020897,and hsa＿circ＿0072745 in serum EVs of RSA patients are abnormally expressed,which may serve as the potential markers for predicting RSA.

Objective To investigate the expression level and clinical significance of circular RNAs(circRNAs)in serum extracellular vesicles(EVs)of patients with recurrent spontaneous abortion(RSA).Methods The serum samples from 3 RSA patients and 3 nor-mal pregnant women(controls)visited our hospital from May 2021 to March 2023 were collected and the gene expression profiling chips were used to screen for differentially expressed circRNAs in serum EVs.Ten RSA patients and 10 normal pregnant women were enrolled in a training set and 80 RSA patients and 64 normal pregnant women were enrolled in a validation set.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the levels of differentially expressed circRNAs between the two groups.The predictive value of differentially expressed circRNAs for RSA was evaluated by the receiver operating characteristic(ROC)curve.Results A total of 57 563 circRNAs in serum EVs were detected by the gene expression profiling chips.Compared with the control group,3 516 circRNAs were differentially expressed in RSA patients,including 2 377 up-regulated and 1 139 down-regulated.The de-tection results of qRT-PCR in the training set and validation set showed that the expression levels of hsa＿circ＿0054403 in serum EVs of RSA patients(2.07[1.00,6.68])was significantly higher than that in the control group(1.00[0.42,1.46],U=1 239,P＜0.01),while those of hsa＿circ＿0020897(0.33[0.11,1.40]vs 1.00[0.46,3.66],U=1 712,P＜0.01)and hsa＿circ＿0072745(0.49[0.22,1.60]vs 1.00[0.51,7.93],U=1 714,P＜0.01)were significantly lower than that in the control group.The ROC curve showed that the hsa＿circ＿0054403,hsa＿circ＿0020897,and hsa＿circ＿0072745 in serum EVs had high predictive value for RSA.Their AUCROC were 0.758,0.666,and 0.664,respectively,and the corresponding sensitivity and specificity were 47.5% and 100.0%,50.0% and 81.2%,and 62.5% and 70.3%,respectively.When the three circRNAs were combined,it's AUCROC,sensitivity,and specificity were 0.842,73.7%,and 79.7%,respectively.Conclusion The hsa＿circ＿0054403,hsa＿circ＿0020897,and hsa＿circ＿0072745 in serum EVs of RSA patients are abnormally expressed,which may serve as the potential markers for predicting RSA.