Clinical Trial And Mechanism Of Three Methods For Termination Of Second Trimester Pregnancies And The Ultrastructure Changes

Objectives:1To evaluated the clinical safety and effectiveness in China ontermination of second-trimester pregnancy using mifepristone combined withintra-amniotic ethacridine lactate versus mifepristone combined with themisoprostol, recommended by WHO, and the Chinese routinely used methodintra-amniotic injection of ethacridine lactate.2To study the effects of different induced labor methods on morphologyand biochemical indicators of placental villus and decidua.3In order to select the suitable induced labor method from two sides,basic and clinical, conforming to China’s nation conditions.Methods:1A clinical comparison study of forty five patients on termination ofsecond-trimester pregnancy using the above three induced labor methods.2The ultrastructure of placental villus and decidual tissue in threeinduced labor methods were investigated by transmission electronmicroscope(TEM).3Immunohistochemistry and image analysis technique were used tocharacterise the expression of NF-κB, COX-2, BAX, BCL-2, TNF-α andTGF-β1in placental villus and decidual tissue of the above three inducedlabor methods.Result:1Comparing to MM+EL group and MM group, significant longer inabortion time and significant more in volume of hemorrhage were observed inpatients of EL group(P<0.05). But comparing to MM group, significant longerin abortion time was observed in patients of MM+EL group(P<0.05), therewas no significant difference in volume of hemorrhage between MM group and MM+EL group.2Tissue morphological changes: no specific lesions were detected inplacenta villus of MM group. With conventional histology, the deciduashowed various degrees of interstitial edema and necrosis, level ofMM<EL<MM+EL; the villi showed various degrees of interstitial edema andpatchy necrosis in EL group and MM+EL group, more serious damage inMM+EL group. At the ultrastructural level, the decidua and villi showedvarious degrees of degeneration and necrosis, MM+EL group was the mostserious damage than the other two groups(MM<EL<MM+EL).3The expression of NF-κB, COX-2, BAX, BCL-2, TNF-α and TGF-β1:Comparing to controls(MM group and EL group), significant increase inNF-κB and TNF-α expression, significant decrease in BCL-2and TGF-β1expression, were all found in decidua and trophoblast of placenta withMM+EL group; but no significant differences were observed between thecontrols(MM group and EL group) in the expression of NF-κB, BCL-2,TNF-α and TGF-β1. There were no significant differences were observedamong the three groups(MM group, EL group, MM+EL group) in decidua andtrophoblast of the expression of COX-2, BAX.Conclusions:1All the MM, EL and MM+EL regimes were effective with high successand were safe for the termination of second trimester pregnancy. But forpregnancies of gestational age over12to16weeks, MM regime was betterthan the other two regimes. For pregnancies of gestational age over16to24weeks,addition of mifepristone to ethacridine lactate may shorten theinduction-to-abortion time compared with the use of ethacridine lactate alonewithout increasing the number of complication.2From the ultrastructure of placenta and the expression of BAX, BCL-2,one of the important mechanisms of rivanol and mifepristone/rivanol inducedlabor was apoptosis/necrosis, and mifepristone could enhance the effect.3The mechanism of Mifepristone abortion was the result that the deciduaand villi apoptosis necrosis (BAX, BCL-2and ultrastructure), inflammation (NF-kappa B), immune rejection (TNF alpha, TGF-beta1) work together tomake prostaglandin synthesis enhancement.4Mifepristone also have synergy to rivanol the aspects of inflammatory(nf-kappa B) and immunization (TNF alpha, TGF-beta1).