Amniotic fluid soluble Toll-like receptor 4 in pregnancies complicated by preterm prelabor rupture of the membranes

Objective: To determine amniotic fluid soluble Toll-like receptor 4 (sTLR4) levels in women with preterm prelabor rupture of the membranes according to the presence of microbial invasion of the amniotic cavity and histological chorioamnionitis and its relation to neonatal outcome. Methods: One hundred two women with singleton pregnancies with a gestational age between 24 + 0 and 36 + 6 weeks were included in a prospective cohort study. Amniocenteses were performed, and the concentrations of sTLR4 in the amniotic fluid were determined using sandwich enzyme-linked immunosorbent assay technique. Results: Women with the presence of microbial invasion of the amniotic cavity had higher sTLR4 levels [median 54.2 ng/mL, interquartile range (IQR) 10.15-289.9] than those without this condition (median 18.1 ng/mL, IQR 8.1-29.9; p = 0.001). Women with the presence of histological chorioamnionitis had a higher sTLR4 level (median 28.0 ng/mL, IQR 11.15-178.1) compared with women without histological chorioamnionitis (median 13.0 ng/mL, IQR 7.8-28.7; p = 0.003). A mixed linear model was used to adjust for confounders. The difference was found only between women with and without microbial invasion of the amniotic cavity in this model. Conclusions: Microbial invasion of the amniotic cavity was associated with higher amniotic fluid sTLR4 levels independent of confounders.