Abstract:

Objective To evaluate the risk factors for major hemorrhage in patients with residual pregnancy tissue （RPT） combined with uterine arteriovenous fistula （UAVF） following early pregnancy abortion by using a nomogram model based on ultrasonic features. Methods A total of 113 patients who had RPT combined with UAVF after early pregnancy abortion and were admitted to our hospital from January 2019 to January 2024 were selected as the study subjects. All the patients underwent ultrasound examination. According to the occurrence of major hemorrhage， the patients were divided into a major hemorrhage group and a non-major hemorrhage group. The ultrasonic characteristics were compared between these two groups. Logistic multivariate analysis was employed to screen the risk factors for major hemorrhage， and a nomogram model was established. The predictive value of the model for major hemorrhage was evaluated using the receiver operating characteristic （ROC） curve. Results Among the 113 patients， the incidence rate of major hemorrhage was 22.12% （25/113）. Ultrasonographic features revealed irregular cysticsolid lesions within the uterine cavity， accompanied by characteristic mosaiclike color flow signals， which suggested RPT combined with UAVF. In the major hemorrhage group， the diameter of dilated vessels， the maximum lesion diameter， the peak systolic velocity （PSV）， and the enddiastolic velocity （EDV） were significantly larger than those in the nonmajor hemorrhage group. Conversely， the resistance index （RI） and the thickness of the lower uterine segment myometrium were significantly smaller （all P < 0.05）. Logistic regression analysis indicated that the diameter of dilated vessels， PSV， and EDV were risk factors for major hemorrhage， whereas the thickness of the lower uterine segment myometrium was a protective factor （all P < 0.05）. The ROC curve demonstrated that the nomogram model based on multivariate analysis had a sensitivity of 96.0% and a specificity of 86.4% for predicting major hemorrhage. Conclusions An increased diameter of dilated vessels， an elevated blood flow velocity， and a thinning of the lower uterine segment myometrium are independent predictive factors for major hemorrhage in patients with RPT combined with UAVF after early pregnancy abortion. The nomogram model established based on these factors exhibits high predictive efficacy.

Key words: early pregnancy loss, residual pregnancy tissue, uterine arteriovenous fistula, massive hemorrhage, digital subtraction angiography