Abstract: To study the expression of matrix metalloproteinase-25(MMP-25) in the villi and decidua of normal early pregnant and spontaneous abortion women and to find the possible function of MMP25 in embry implantation and its relationship with spontaneous abortion. Methods Semi-quantitative RTPCR and immunohistochemistry were used to determine the expression and distribution of MMP-25 mRNA and protein in villi and decidua of normal early pregnant and spontaneous abortion women. Results① MMP-25 mRNA expressed in villi and decidua of the normal early pregnancy group and increased with the raise of pregnancy weeks in each group, also it was significantly increased compared with the abortion group, and the differences among each week and between the pregnancy group and the abortion group were significant (both P＜0.05). ② In villous tissues, MMP-25 expressed in the cytotrophoblasts and syncytiotrophoblasts and increased with the increase of pregnancy week in the normal early pregnancy group, however it only expressed in the syncytiotrophoblasts in the abortion group, and the mean ODs of the two groups were 0.21±0.02 and 0.13±0.04(P＜0.05)． In deciduous tissues, MMP-25 mainly expressed in the glandular epithelium cells in the normal early pregnancy group and was very weak in the abortion group, and the mean ODs of the two groups were 0.25±0.13 and 0.21±0.12(P＜0.05). Conclusion MMP-25 may play an important role in the embryo implantation and placentation. The decrease of MMP-25 may relate to spontaneous abortion.

Key words: Matrix metalloproteinase-25, Early pregnancy, Spontaneous abortion, Villi, Decidua