PROSTAGLANDIN-F2-ALPHA OUTPUT BY AMNION-CHORION-DECIDUA - RELATIONSHIP WITH LABOR AND PROSTAGLANDIN E(2) CONCENTRATION AT THE AMNIOTIC SURFACE

OBJECTIVE: Our purpose was to evaluate prostaglandin F-2 alpha output at fetal membrane surfaces relative to labor and to assess amniotic prostaglandin E(2) concentration changes on prostaglandin F-2 alpha output. STUDY DESIGN: Intact and separated fetal membranes from 10 elective cesarean sections and nine vaginal deliveries were incubated in double-sided perfusion chambers. Prostaglandin F-2 alpha and 13,14-dihydro-15-keto-prostaglandin F-2 alpha output was measured by radioimmunoassay. Alterations of prostaglandin F-2 alpha and 13,14-dihydro-15-keto-prostaglandin F-2 alpha output were assessed after exogenous prostaglandin E(2) addition at amniotic surfaces of intact membranes. RESULTS: Prostaglandin F-2 alpha concentration was higher at maternal surfaces of intact but not separated membranes after labor (p = 0.0001). Amniotic 13,14-dihydro-15-keto-prostaglandin F-2 alpha was increased in association with preceding labor (p = 0.038). Addition of prostaglandin E(2) at the amniotic surface did not alter prostaglandin F-2 alpha or 13,4-dihydro-15-keto-prostaglandin F-2 alpha production. CONCLUSION: Prostaglandin F-2 alpha concentration at the maternal surface of fetal membranes likely plays a critical role in induction or maintenance of myometrial contractions associated with term labor independent of amniotic fluid prostaglandin E, concentrations.