Objective: We sought to evaluate the distribution of scavenger receptor for hemoglobin positive (CD163(+)) cells in the placenta and fetal membranes from pregnancies complicated by preterm prelabor rupture of membranes with respect to the presence and absence of histological chorioamnionitis.
Methods: Sixty-two women with singleton pregnancies with a gestational age between 24+0 and 36+6 weeks were included in a prospective cohort study. CD163 was evaluated by immunohistochemistry in the placenta and fetal membranes. The number of CD163(+) cells and neutrophils was counted in the following locations: fetal membranes' amnion, chorion, and decidua, as well as the placenta's amnion, chorionic plate, subchorionic fibrin, stem villi, terminal villi, and decidua.
Results: CD163(+) cells were found in all compartments of the placenta and the fetal membranes regardless of the inflammatory status. A positive correlation between the number of CD163(+) cells and neutrophils in the subchorionic fibrin and the chorionic plate was found. The number of CD163(+) cells was higher in the placental subchorionic fibrin and chorionic plate when histological chorioamnionitis was present.
Conclusion: The presence of histological chorioamnionitis affected the number of CD163(+) cells in the placental chorionic plate and in the subchorionic fibrin but not in the fetal membranes.