Preterm premature rupture of membranes (PPROM) is defined as rupture of membrane 
that happens before the onset of labor and 37 weeks. Subclinical intrauterine 
infection is major etiological factor in the pathogenesis that increases 
mortality and morbidity associated with PPROM. This study was performed to 
evaluate the levels of maternal serum urokinase plasminogen activator receptor 
(uPAR), ST2 and interleukin (IL)-33 in PPROM and its relation with maternofetal 
infectious and morbidity. A total of 74 pregnant women, of which 49 with PPROM 
between 24 and 34 weeks gestation, and 25 normal pregnant women without PPROM 
were included in the study. Study group was seperated into 2 subgroups as PPROM 
and PPROM-histological chorioamnionitis (PPROM-HC). The blood samples were taken 
before the any medication. The mean serum IL-33, ST2, and uPAR values in the 
PPROM-HC group were significantly higher than PPROM and control group. The 
cut-off values of IL-33, ST2, and uPAR were determined as 5.2, 2 and 6.4 ng/mL, 
respectively. A cut-off value of IL-33 of 5.2 ng/mL, the cut-off of ST2 of 2 
ng/mL and the cut-off of uPAR of 6.4 ng/mL showed similar sensitivity, 
specificity to IL-6 and the better sensitivity and specificity as compared to 
C-reactive protein and total leucocyte count in predicting infection in PPROM. 
We evaluated the predictive value of uPAR, ST2 and IL-33 in PPROM and we 
concluded that all of them can be used as reliable biomarkers to determine 
infection without any clinical signs but it is necessary to be studied in 
different cohort groups and infectious diseases.