Laminaria versus extra-amniotic saline solution infusion for cervical ripening in second-trimester labor inductions

The aim of this study was to determine which cervical ripening method, laminaria placement or extra-amniotic saline solution infusion, was associated with the shorter interval from induction to delivery in the second trimester.

Women admitted for indicated second-trimester labor induction with an unfavorable cervix were randomly assigned to receive either intracervical placement of laminaria (n = 25) or extra-amniotic saline solution infusion (n = 25) with concurrent concentrated oxytocin and vaginally administered prostaglandin E2 (10 mg every 6 hours). Treatment success was defined as an interval from induction to delivery of < or =24 hours.

Maternal age, race, parity, gestational age, and initial cervical dilatation were similar between the groups. Indications for uterine evacuation were also similar and included fetal death (n = 7), aneuploidy (n = 20), fetal structural anomaly (n = 18), and maternal indications (n = 4). There was no difference in the mean intervals from induction to delivery (laminaria, 16 +/- 8 hours, vs extra-amniotic saline solution infusion, 17 +/- 10 hours) or the number of treatment successes (laminaria, n = 23, vs extra-amniotic saline solution infusion, n = 21). Retained placenta, live birth, and hemorrhage occurred with similar frequencies in the two groups.

Relative to laminaria, extra-amniotic saline solution infusion did not shorten the induction-to-delivery interval in women undergoing indicated second-trimester labor induction with concentrated oxytocin and low-dose vaginally administered prostaglandin E2.