Amniotic fluid myeloperoxidase in pregnancies complicated by preterm prelabor rupture of membranes

Objective: To determine amniotic fluid myeloperoxidase concentration in women with preterm prelabor rupture of the membranes with microbial invasion of the amniotic cavity and histological chorioamnionitis. Methods: One hundred eighty-one women with singleton pregnancies with a gestational age between 24+0 and 36+6 weeks were included in this study. Amniocenteses were performed, and myeloperoxidase concentration in the amniotic fluid was determined using ELISA. Result: Women with microbial invasion of the amniotic cavity had higher median myeloperoxidase concentration than women without this condition (149.2 ng/mL vs. 54.6 ng/mL; p = 0.0006). Women with the presence of histological chorioamnionitis had higher median myeloperoxidase concentration than women without histological chorioamnionitis (103.7 ng/mL vs. 50.0 ng/mL; p = 0.0001). The presence of both microbial invasion of the amniotic cavity and histological chorioamnionitis was associated with higher median myeloperoxidase concentration (456.0 ng/mL vs. 52.9 ng/mL; p < 0.0001). The results remained significant after adjusting for gestational age. Conclusions: Increased amniotic fluid myeloperoxidase in microbial invasion of the amniotic cavity and histological chorioamnionitis confirm a role of myeloperoxidase in preterm prelabor rupture of the membranes pathophysiology.