MMP9 and preterm premature rupture of the membranes: MMP-9 has been shown to mediate the key events leading to membrane rupture in fetal membranes, and MMP-9 expression was also found to be elevated in the AF of PPROM women with MIAC; moreover, to our knowledge, previous research did not investigate the changes in MMP-9 levels in AF associated with imminent SPTD in the context of PPROM.