Open AccessAbnormal expression of MMP‐9 and imbalance of MMP‐9/TIMP‐1 is associated with prolonged uterine bleeding after a medical abortion with mifepristone and misoprostol
Author(s) -
LI LI,
ZHOU ZANHUA,
HUANG LILI
Publication year - 2009
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.1080/00016340902898024
Subject(s) - mifepristone , medicine , misoprostol , medical abortion , matrix metalloproteinase , abortion , obstetrics , metrorrhagia , gynecology , pregnancy , family planning , research methodology , population , biology , genetics , environmental health
Objective. To investigate the expression of matrix metalloproteinase‐9 (MMP‐9) and tissue inhibitory of metalloproteinase‐1 (TIMP‐1) in women who had undergone a medical abortion and explore their possible role in the mechanism of prolonged uterine bleeding after a mifepristone‐misoprostol abortion. Design . Cross‐sectional study. Setting . Tertiary referral university hospital. Sample . Forty women were recruited following a medical abortion with mifepristone and misoprostol, 20 with duration of bleeding >14 days and 20 with duration of bleeding ≤ 14 days. Methods. Endometrial specimens were stained with hematoxylin and eosin for histological examination. The expression of MMP‐9 and TIMP‐1 was evaluated by immunohistochemistry. Main outcome measures . Histology was analyzed by light microscope and expression of MMP‐9 and TIMP‐1 was semi‐quantitatively evaluated. Results . Histological examination showed residual villi and trophoblasts with inflammatory cell infiltration in women with duration of bleeding >14 days after a medical abortion (bleeding group), whereas each sample of women with duration of bleeding ≤ 14 days after a medical abortion (control group) showed normal endometrial changes. Immunohistochemistry and semi‐quantitative scoring showed a significantly decreased expression level of MMP‐9 in the bleeding group, compared with the control group. There was no significant difference of TIMP‐1 expression between the bleeding group and the control group. The MMP‐9/TIMP‐1 ratio value was significantly lower in the bleeding group than in the control group. Conclusion . This study documents that prolonged bleeding after a medical abortion with mifepristone and misoprostol is associated with retained products of conception with inflammatory cell infiltration, abnormal expression of MMP‐9 and imbalance of MMP‐9/TIMP‐1.