THE RELATIONSHIP OF AMNIOTIC-FLUID CYTOKINES AND PRETERM DELIVERY, AMNIOTIC-FLUID INFECTION, HISTOLOGIC CHORIOAMNIONITIS, AND CHORIOAMNION INFECTION

Objective: To assess the association between cytokines in the amniotic fluid (AF) and preterm delivery, the isolation of bacteria from the A F or chorioamnion, and histologic chorioamnionitis. Methods: Fifty afe brile women with intact membranes in preterm labor at or before 34 wee ks' gestation underwent anmiocentesis. Cytokine levels were measured i n AF, and cultures were performed. Placentas were cultured and examine d histologically. Results: Thirty-two (64%) of the 50 patients deliver ed at or before 34 weeks' gestation. Delivery at or before 34 weeks, c ompared with delivery after 34 weeks, was related to increased levels of interleukin-6 (IL-6) (88 versus 12%; P < .001), interleukin-1 (IL-1 ) alpha (50 versus 6%; P = .004), IL-1 beta (42 versus 0%; P = .002), and prostaglandin (PG) E, (66 versus 22%; P = .008). Bacteria were rec overed from the AF of nine (18%) of the 50 patients. All of the cytoki nes with increased levels, plus tumor necrosis factor (TNF)-alpha, wer e related to bacteria in the AF. Increased IL-6, IL-1 alpha, IL-1 beta , TNF-alpha, and PGE2 were also associated with histologic chorioamnio nitis among women who delivered within 1 week of amniocentesis. Elevat ed cytokine levels were not related to chorioamnion infection. Conclus ions: Elevated AF cytokines and PGE, predicted delivery before 34 week s' gestation and delivery within 7 days of the amniocentesis, as well as AF infection and histologic chorioamnionitis. These findings suppor t the hypothesis that infection is one cause of preterm delivery, oper ating via a mechanism involving induction of cytokine production.