OPTIMIZATION OF APPROACHES TO USING MIFEPRISTONE TO PREPARE FOR LABOR

Objective. To optimize approaches to preparing the cervix uteri for labor with mifepristone in patients tending to prolong pregnancy and to define their management tactics after inadequately ineffective initial preparation with th is drug. Subjects and methods. One hundred and twenty-two patients at 256—298 days gestation were examined. Mifepristone alone was used to prepare 90 women (Group 1) for labor; if the agent was inadequately effective, the following labor preparation stage or labor induction was made in 32 women (Group 2) Results. After the use of mifepristone, regular labor activity developed during preinduction in 84.2% before 287 days gestation and in 61.4% at >287 days. The risk for labor abnormalities showed a 1.7-fold increase with advancing gestational age at which preinduction was initiated (p=0.02). Moreover, at 42 weeks or more gestation, the need to continue preinduction was generated 2.5 times more frequently (p=0.015). The outcomes of preinduction were comparatively analyzed to determine whether it was reasonable to continue preparation for labor if mifepristone was inadequately effective. The active phase of labor was achieved in 90 and 68.8% of Groups 1 and 2 women, respectively (p=0.03). The latter group was also characterized by the high rate of abnormalities in labor activity (34.4% versus 18.9%;p=0.009) and abdominal delivery (40.6% versus 25.5%;р=0.09) Conclusion. 1. The optimal gestational age at which mifepristone preinduction is the maximum effective is 40 weeks 4 days to 40 weeks 5 days. 2. It is reasonable to continue preparation for labor if mifepristone is inadequately effective in certain clinical situations; however, account must be taken of the reduced efficiency of the used methods and the increased risk of cesarean delivery.

mifepristone, preparation for delivery, induction, prolonged pregnancy, ineff iciency of induction