The serum levels of circulating matrix metalloproteinase MMP-9, MMP-2/TIMP-2 complex and TIMP-1 do not change significantly during normal pregnancy: a pilot study

OBJECTIVE: Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. They exhibit proteolytic activity implicating the efficiency of trophoblast invasion to the uterine wall involving marked hemodynamic and uterine changes. In this pilot study sera of 13 women with normal pregnancy was analyzed to evaluate the usage of MMPs as diagnostic tool. The concentrations of circulating MMP-9, MMP-2/TIMP-2 complex and TIMP-1 in different time points during normal pregnancy has not been studied. The serum levels of MMP-9, TIMP-1, TIMP-2 and MMP-2/TIMP-2 complex were determined by enzyme-linked immunosorbent assay (ELISA). Using the same method, we have shown that serum MMPs are elevated in spontaneous early pregnancy failure as compared to normal pregnancy. RESULTS: The serum levels of MMP-9 and TIMP-1 were stable throughout pregnancy. The level of MMP-2/TIMP-2 complex was slightly increased after week 15 without statistical significance. For our best knowledge, this is a first study of the serum levels of MMP-9, MMP-2/TIMP-2 and TIMP-1 on different time points during normal pregnancy. Further measurements with the correlation to the outcome of the pregnancy are needed.