Cervical fetal fibronectin correlates to prostaglandin E2–induced cervical ripening and can be identified in cervical tissue

OBJECTIVE: Our purpose was to investigate whether prostaglandin E2–induced cervical ripening can be related to changes in fetal fibronectin levels and whether fetal fibronectin can be detected by immunohistochemistry in amniotic and cervical tissue. STUDY DESIGN: Fetal fibronectin levels in cervical mucus were quantitated in 28 nulliparous term pregnant women with unfavorable cervical states before and after intracervical application of prostaglandin E2 gel. The concentration of fetal fibronectin was determined with use of an enzyme immunoassay. Cervical biopsy specimens and amniotic tissue for immunohistochemical analysis were obtained from three term pregnant women and after parturition in three women. Cervical biopsy specimens from two nonpregnant women served as controls. Immunohistochemical analysis was performed with antibodies directed toward fetal fibronectin. RESULTS: The fetal fibronectin level in cervical mucus was low in all women before prostaglandin E2 application. In women with a successful prostaglandin E2–induced ripening (i.e., an increase of cervical score with ?3 points), a tenfold increase in the fetal fibronectin level was registered. In women with an insufficient cervical ripening after prostaglandin E2 treatment no significant increase in the fetal fibronectin level was registered. The immunohistochemical analyses have identified fetal fibronectin in the epithelial cells of the cervix uteri. CONCLUSION: Successful prostaglandin E2–induced cervical ripening seems to be related to a significant increase in cervical fetal fibronectin levels. Fetal fibronectin can be detected immunohistochemically in the pregnant human cervix. (Am J Obstet Gynecol 1998;178:540-5.)