Preterm premature rupture of membranes (PPROM), which precedes approximately 30–40% of preterm births, is the main cause of neonatal morbidity, mortality, and long-term sequelae. In particular, almost half of all PPRPM cases are frequently complicated by subclinical acute inflammation in the placenta and fetal tissue, commonly named as acute histologic chorioamnionitis [HCA]. Increasing evidences suggest that HCA carries additional risks to both the pregnant women and their fetuses, including greater risk of imminent preterm birth, as well as sepsis, neurologic morbidity, and mortality in neonates. More accurate and early prenatal predictive markers (especially noninvasive ones) are urgently needed for identifying subclinical HCA in the context of PPROM.To identify potential biomarkers in the plasma that could predict histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM), using shotgun and targeted proteomic analyses.