Objective To explore the cervical softening effect of mifepristone by shear wave elastography（SWE）before painless abortion surgery.MethodsA total of 87 pregnant women who underwent painless abortion surgery in our hospital were selected

and randomly divided into a test group of 43 cases and a control group of 44 cases.The test group took50 mg of mifepristone at 8 pm the day before surgery

while the control group took no medication.The SWE technique was used to measure the shear wave veloaty（SWV）of the external os anterior and posterior at the day before the surgery （before the medication of the test group）and on the day of the surgery.The differences of SWV measured 2 times in the test group and the control group were compared.The relationship between the cervical SWV measured on the day of surgery and the intraoperative cervical dilation evaluation was analyzed.ResultsThe SWV of the external os anterior and posterior measured one day before the surgery in the test group were statistically different from those measured on the day of the surgery（both P<0.05）.There were no statistic difference between the SWV of the external os anterior and posterior measured one day before the surgery and the value measured on the day of the surgery in the control group.The results of correlation analysis showed that the SWV of the external os anterior on the day of surgery was positively correlated with the intraoperative cervical dilation evaluation（r=0.458

P<0.05）.There was no significant correlation between the SWV of the external os posterior and the intraoperative cervical dilation evaluation.Conclusion SWE can be used to detect the cervical softening effect caused by mifepristone.SWV of the external os anterior is expected to be one of the indicators for objectively evaluating cervical softness.