【摘要】 目的　观察米非司酮中期引产胎盘的病理变化及探讨米非司酮的作用机制。方法　将 70例宫内妊娠 16～ 2 0周要求引产的健康妇女随机分成两组 :Ⅰ组 (试验组 ) 1～ 3d服米非司酮共 3 0 0mg ,第 4d服用米索 ;Ⅱ组 (对照组 )水囊引产。两组均于分娩后取胎盘制备光镜及电镜标本。光镜检查 ,对胎盘各成分进行定性观察比较 ,纤维化绒毛定量分析 ,图像分析仪计算绒毛面积指数 ;透射电镜观察绒毛中滋养细胞、绒毛间质微血管、蜕膜细胞、颗粒细胞、间质的病理变化。免疫组化分析采用第八因子相关抗原 (FⅧRAg)单克隆抗体 ,SP免疫组化染色法 ,计算绒毛微血管密度 (MVD)。统计学处理用SAS系统进行t检验、χ2 检验。结果　与Ⅱ组比较 ,Ⅰ组绒毛面积指数减少 (P <0 0 1)、纤维化绒毛增多 (P <0 0 0 5 )、绒毛间质MVD下降 (P<0 0 1)、内皮细胞受损FⅧRAg表达量降低 ,合体滋养细胞的微绒毛数量减少、变短、脱失 ;细胞变性明显。内皮细胞变性。蜕膜细胞粗面内质网、线粒体减少 ;颗粒细胞高电子密度颗粒减少或消失。结论　米非司酮对中期引产胎盘绒毛滋养细胞、间质微血管、蜕膜细胞、颗粒细胞 ,产生了较明显的影响 ,对用于终止晚期妊娠应持慎重态度更多还原

【Abstract】 Objective To study the effect of mifepristone used for induced labor on the structure of placenta. Methods A randomized comparative study was performed in 70 normal pregnant women who requested induced labor at 16～20 weeks’ gestation.These women were randomly divided into 2 groups.In group 1(experimental group),women took mifepristone 100 mg orally per day for 3 days(total dose 300 mg).On the fourth day, misoprostol was added.In group 2 (control group),women were given water bag induced labor.The placenta samples of 2 groups after labor were observed under light and electron microscopes. Villi in 2 groups were researched with monoclonal antibody to factor Ⅷ related antigen(FⅧRAg)and streptaviin peroxidase(SP) methods,and a series of digital processors. Results Compared with group 2,the fibrotic villi were more ( P< 0 005)and the index of the villose square was lower( P< 0 01)in group 1.The villi and decidua of placenta showed more extensive and severer degeneration in group 1 than in group 2 under light and electron microscopes.Mifepristone reduced FⅧRAg staining and the micrangium density of villi significantly decreased in group 1 ( P <0 01). Conclusion Mifepristone can influence the structure of placenta in second trimester pregnancy.It should be prudent to use mifepristone for pregnant women in third trimester pregnancy.更多还原