Interleukin 8 concentrations in amniotic fluid and peripheral venous plasma during human pregnancy and parturition

Abstract

To establish the gestational and labour-associated changes in interleukin 8 (IL-8) release, we have determined the concentration of this cytokine in maternal peripheral plasma and amniotic fluid from 1 5 weeks of gestation to term and in association with spontaneous-onset labour at term and preterm. No statistically significant changes in peripheral plasma IL-8 concentration were observed during pregnancy or in association with labour onset (mean concentration 56.5±14.5 ng/l, N = 64). The IL-8 concentrations in amniotic fluid were up to 50-fold greater than those observed in peripheral plasma (p<0.05) and increased significantly (p<0.05) during pregnancy. At term, but before the onset of labour, amniotic fluid concentrations of IL-8 averaged 969.2±553.5 ng/l (N= 12). In association with labour at term, IL-8 concentrations increased to 3895.8±1414.4 ng/l (N=6, p<0.03). The concentration of IL-8 in amniotic fluid obtained from women in preterm labour averaged 1854.7±1352.6 ng/l (N=6) but was not statistically different from the concentration of IL-8 in amniotic fluid obtained from gestational aged-matched non-labouring controls. Although the precise role of intrauterine IL-8 at the time of parturition awaits elucidation, these data support the concept that this cytokine may be involved in the biochemical events associated with the onset and/or propagation of normal labour in the human.