Spontaneous abortion is one of the most common complications of pregnancy， and two or more spontaneous abortions in a row are defined as recurrent spontaneous abortion （RSA）， of which about half of patients have unknown etiology. However， the pathogenesis of unexplained RSA （URSA） has not been elucidated， and the lack of effective treatment has made it one of the key and difficult points in the field of obstetrics and gynecology. This article conducts a literature review of recent research on URSA and finds that the pathogenesis of URSA is related to the imbalance of immune tolerance at the maternal-fetal interface， apoptosis of trophoblast cells， inhibition of angiogenesis， and activation of immune responses. Immunotherapy （including cell therapy， cytokine therapy， and immunosuppressive intervention）， hormone drugs， anticoagulant regimens， and traditional Chinese medicine therapies are commonly used in clinical practice to intervene in URSA， but the safety and effectiveness of some therapies are still controversial.

Objective:To assess a value of dual energy index(DEI)and effective atomic number(Zeff)of dual-energy computed tomography(DECT)combined with slope of energy spectrum curve in identifying the component of urinary tract stones.Methods:The clinical and DECT imaging data of 111 patients with urinary tract stones who admitted to Nantong Haimen People's Hospital from October 2019 to October 2022 were selected,and the diameters of the urinary tract stones of all patients were<5 mm.The components of outside body stones of all patients were analyzed by infrared spectrum.The accuracy,sensitivity and specificity of the DEI,Zeff,slope of energy spectrum curve and the combination of the them were respectively calculated in identifying the components of urinary tract stones.Results:In 111 patients,the patients with calcium oxalate stones were 75(67.57%),and ones with hydroxyapatite were 15 cases(13.51%),and ones with uric acid stones were 21 cases(18.92%),and there were no other type of stone included cysteine.The differences of CT values(F=487.691,P<0.001),DEI values(F=395.553,P<0.001),Zeff values(F=818.689,P<0.001)and the slopes of energy spectrum curves(H=19.615,P<0.001)were statistically significant among the three types of stones.The overall accuracies of DEI,Zeff and slope of energy spectrum curve were 87.39%(97/111),84.68%%(94/111)and 81.98%(91/111)in identifying the components of urinary tract stone.The range of diagnostic accuracies of DEI,Zeff and the slope of energy spectrum curve was between 80%and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.The overall accuracy of DEI,Zeff combined with slope of energy spectrum curve was 94.59%(105/111)in identifying the components of urinary tract stones.The diagnostic accuracies of DEI,Zeff combined with slope of energy spectrum curve were respectively 94.59%,94.59 and 100%for calcium oxalate stones,hydroxyapatite and uric acid stones.Conclusion:Compared with the single indicator of DECT,the DEI and Zeff combined with the slope of the energy spectrum curve showed better diagnostic accuracy in identifying the components urinary track stones.