Enhancement of amniotic cyclooxygenase type 2 activity in women with preterm delivery associated with twins or polyhydramnios

OBJECTIVE: We tested the hypothesis that preterm delivery in women with twi ns or polyhydramnios is associated with enhanced expression and activity of cyclooxygenase type 2 in the amnion. STUDY DESIGN: We obtained amniotic tissue samples from women undergoing pre term delivery complicated by either twins or polyhydramnios and also from w omen undergoing preterm cesarean delivery before or after labor. We measure d amniotic prostaglandin E-2 content and determined cyclooxygenase type 1 a nd type 2 expressions. We inhibited cyclooxygenase type 1 and type 2 activi ties with selective inhibitors. RESULTS: Preterm delivery attributed to twins or polyhydramnios was associa ted with higher prostaglandin E-2 production and enhanced amniotic expressi on of cyclooxygenase type 2. In contrast, cyclooxygenase type 1 expression was unchanged. Incubation of amniotic samples in vitro with either indometh acin or the selective cyclooxygenase type 2 inhibitor SC-236, but not with the cyclooxygenase type 1 inhibitor SC-560, effectively reduced prostagland in E-2 production. CONCLUSION: Preterm delivery related to multiple gestation or polyhydramnio s was associated with enhanced amniotic expression and activity of cyclooxy genase type 2.