Amniotic fluid 5-hydroxyeicosatetraenoic acid in preterm labor

5-Hydroxyeicosatetraenoic acid (5-HETE) is an arachidonate lipoxygenase product capable of stimulating human uterine contractility in a dose-dependent manner in vitro. The purpose of this study was to determine if preterm labor is associated with changes in the concentration of this metabolite in amniotic acid. Amniotic fluid was obtained by transabdominal amniocentesis from three groups of women with preterm labor: group 1 — women without intraamniotic infection who responded to tocolysis (n = 32); group 2 — women without intraamniotic infection who failed to respond to tocolysis (n = 22); and group 3 — women with intraamniotic infection (n = 14). 5-HETE was determined by radioimmunoassay. The median amniotic fluid concentration of 5-HETE in women who responded to tocolysis (median = 1412 pg/ml; range: 111–3547) was significantly lower than in women who delivered despite tocolysis (median = 2052 pg/ml; range 136–7774) and women with intraamniotic infection (median = 1876 pg/ml; range: 543–7033) [p < 0.05]). No difference in amniotic fluid concentrations' of 5-HETE were found between women in groups 2 and 3 (p 〉 0.05).