Increased amniotic fluid leukotriene C4 concentration in term human parturition.

The purpose of this study was to determine whether parturition is associated with changes in the amniotic fluid concentration of leukotriene C4, an arachidonate lipoxygenase metabolite. Amniotic fluid was collected from 36 women not in labor and from 30 women in active labor with cervical dilation of greater than or equal to 6 cm. The concentration of leukotriene C4 was determined by radioimmunoassay. The median amniotic fluid concentration of leukotriene C4 was greater in laboring women than in nonlaboring women: 121 pg/ml (range, 52 to 261 pg/ml) versus 73.5 pg/ml (range, 6 to 249 pg/ml), respectively (p = 0.0008). These data are consistent with activation of the lipoxygenase pathway during spontaneous parturition at term.