Development of a Nomogram for Predicting Intravasation Before Transvaginal 4-Dimensional Hysterosalpingo-Contrast Sonography

BACKGROUND: Intravasation during transvaginal 4-dimensional hysterosalpingo-contrast sonography (TVS 4D-HyCoSy) may lead to false-negative results in tubal patency evaluation. Although the influencing factors associated with intravasation have been investigated, some factors are only identified during 4D-HyCoSy, thus currently no studies on preventing intravasation. However, several preprocedural features can be collected in advance, which may be valuable in predicting intravasation. OBJECTIVE: The purpose of this study is to establish a nomogram incorporating the preprocedural features to predict the risk of intravasation before TVS 4D-HyCoSy. METHODS: The data of 276 infertile women with patent fallopian tubes were analyzed retrospectively. They were assigned to the study group (n = 62) and the control group (n = 214) according to the development of intravasation. The preprocedural characteristics were collected to investigate the predictors independently associated with intravasation, which were then served as the construction of a nomogram. The performance of the nomogram was verified internally. RESULTS: History of uterine curettage (OR = 2.341, P = 0.009), endometrial thickness (OR = 0.587, P < 0.001), and examination schedule (OR = 0.790, P = 0.024) were found to be the independent influencing factors associated with intravasation. The established nomogram incorporating these preprocedural features was useful for predicting the risk of intravasation prior to 4D-HyCoSy. It yielded net benefits when the predicted probability was less than 50%. CONCLUSION: The nomogram incorporating the preprocedural characteristics achieved a net benefit for clinical decision-making when the estimated risk was less than 50%. It is recommended to change the examination schedule for patients with an estimated risk greater than 50% and perform 4D-HyCoSy when the risk is less than 50%.