Sl. Hillier et al., THE RELATIONSHIP OF AMNIOTIC-FLUID CYTOKINES AND PRETERM DELIVERY, AMNIOTIC-FLUID INFECTION, HISTOLOGIC CHORIOAMNIONITIS, AND CHORIOAMNION INFECTION, Obstetrics and gynecology, 81(6), 1993, pp. 941-948
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.