MMP9 and infection: While MMP-2 and MMP-9 are physiologically involved in trophoblast invasion and angiogenesis, and MMP-3 in cervical remodeling (Timokhina et al., 2020), their overexpression has been associated with pregnancy complications such as preeclampsia, infection, and preterm labor (Barron et al., 2024; Mirani et al., 2025).