Peripheral Blood Expression of MMPs and DNA Methylation-Related Genes in Women with Recurrent Spontaneous Abortion: A Case-Control Study

<ns3:p>Background Recurrent spontaneous abortion (RSA) is one of the most common reproductive complications among women of childbearing age. Several factors—including genetic, anatomical, endocrine, infectious, environmental, and immunological causes—have been implicated in RSA. This study aimed to explore the potential association between RSA and the expression patterns of selected genes involved in critical biological processes related to pregnancy maintenance and miscarriage. Methods The relative expression levels of <ns3:italic>matrix metallopeptidase 2 (MMP2)</ns3:italic>, <ns3:italic>matrix metallopeptidase 9 (MMP9)</ns3:italic>, <ns3:italic>DNA methyltransferase 1 (DNMT1)</ns3:italic>, <ns3:italic>DNA methyltransferase 3 alpha (DNMT3A)</ns3:italic>, and <ns3:italic>methylenetetrahydrofolate reductase (MTHFR)</ns3:italic> were evaluated using peripheral blood samples from 30 women with a history of two or more spontaneous abortions (cases) and 30 age-matched non-pregnant women with no history of miscarriage and at least one successful pregnancy (controls). Results No significant differences in the mRNA expression levels of the target genes were observed between women with RSA and the control group. Conclusions Our findings suggest that peripheral blood gene expression profiles of <ns3:italic>MMP2, MMP9, DNMT1, DNMT3A</ns3:italic>, and <ns3:italic>MTHFR</ns3:italic> may not adequately reflect tissue-specific changes associated with RSA. Further investigations using relevant tissues, such as placental or decidual samples, are warranted to better understand the molecular mechanisms underlying RSA.</ns3:p>