Induced cervical ripening with Mifepristone in first trimester abortion. A double-blind randomized biomechanical study.

Mifepristone (RU 486; Roussel-Uclaf, Paris, France) is an antiprogesterone used for termination of very early pregnancy. The ripening effect of Mifepristone on the human pregnant cervix was studied in 42 healthy women from 7 to 11 weeks gestation. The women were randomly allocated to oral treatment of either 100 mg Mifepristone or placebo for 24 and 12 hours before vacuum aspiration. An objective method has been designed to measure the force necessary to step-wise dilate the cervix from 4 to 11 mm. Significant (p less than 0.05) changes in the stiffness of the cervix were demonstrated in patients treated with Mifepristone, reflecting ripeness. The treatment was simple and had no side effects.