Tissue concentrations of cytokines in the lower uterine segment during preterm parturition

Abstract

Aims: To determine the concentrations of tumor necrosis factor α, interleukin-1β, interleukin-6, and interleukinin the lower uterine segment during preterm parturition. Methods: In 71 patients who delivered prematurely nonelective cesarean tissue specimens were obtained from the lower uterine segment. The patients were grouped in relation to the stage of cervical dilatation (< 2 cm, 2–< 4 cm, ≥ 4 cm), duration of labor (≤ 6h, > 6–12 h; > 12 h), and parity (1 versus > 1). Cytokine concentrations in protein extracts of the tissue samples were measured using enzyme-linked immunosorbent assays. Results: Median concentration of tumor necrosis factor α did not change, but that of interleukin-1β, interleukin-6, and interleukin-8 were significantly higher at 2–< 4 cm than at < 2 cm cervical dilatation (6.6, 67.7, and 125.8 versus 1.1, 17.6, and 22.2 pg/mg protein, respectively). The concentrations of interleukin-6 and interleukin-8 showed a further increase at ≥ 4 cm (297.2 and 468.6 pg/mg, respectively), but for interleukin 1β a decrease was observed (0.6 pg/mg). Cytokine concentrations were not related to duration of labor or parity. Conclusions: Local inflammationassociated changes that are mainly related to the stage of cervical dilatation and to only a minor degree to uterine activity may play a crucial role in preterm parturition.