Effectiveness of extra-ovular injection of prostaglandin E2 in tylose gel to ripen the cervix prior to elective induction of labor at term.

Ripening of the unfavorable cervix (Bishop score less than or equal to 4) was obtained in 92 clinically normal gravidae at term (68 nulliparae and 24 parous women), not in labor and with intact membranes, by injecting one or two doses (250 to 500 mug each) of prostaglandin (PG)E2 suspended in a viscous gel (5% Tylose) into the extra-ovular space. On average 7 to 8 hours after the injection the mean increase of the cervical score was 3.7 and 4.1 in the nulliparous and parous women, respectively. Complications associated with placement of the catheter were few. The method is simple, well tolerated and no untoward maternal or perinatal effects could be directly attributed to it. However, suitable criteria for predicting both the effect of the procedure and the optimal PG dose to be administered are still needed.