Mifepristone for labour induction after previous caesarean section. The effects of mifepristone on cervical ripening and labor induction in primigravidae. Labor induction in women at term with mifepristone (RU 486): a double-blind, randomized, placebo-controlled study. Cervical ripening with mifepristone before labor induction: a randomized study. Induction of labor with mifepristone--a randomized, double-blind study versus placebo. Use of mifepristone to ripen the cervix and induce labor in term pregnancies.
To evaluate the efficacy and tolerance of mifepristone in women undergoing induction of labour at term after previous caesarean section.
                A prospective double blind placebo controlled trial.
                Thirty-two women at term (after 37.5 weeks' amenorrhea) who had had a previous caesarean delivery with a low transverse uterine incision. All women had a clear clinical indication for induction of labour with unfavourable cervical conditions (Bishop's score < 4). They were randomised to receive either 200 mg of mifepristone or placebo on days one and two of a four-day observation period.
                Thirteen women entered spontaneous labour: 11 were treated with mifepristone and two were in the control group (P < 0.01). Thirteen women, still with an unfavourable cervix on day four needed cervical ripening with vaginal tablets of prostaglandins. Of these, four had received mifepristone and nine the placebo. Mean oxytocin requirements were lower in the mifepristone group (P < 0.01) and the mean time interval between day one and start of labour was also significantly shorter in this group. Mode of delivery and neonatal outcome were similar in both groups.
                Induction of labour is facilitated in term women with prior caesarean section by the use of mifepristone. This induction agent appears safe and useful with no adverse events on the fetus or mother. To compare the effects of 50 mg or 200 mg of oral mifepristone with placebo on cervical ripening and induction of labor in primigravid women at term with unfavorable cervices.
                This was a double-blind study in which 80 primigravidae at term with a modified Bishop score of 4 or less were randomly assigned to one of three treatment groups. They were assessed at 24-hour intervals for 72 hours, after which labor was induced if it had not occurred spontaneously.
                Two hundred milligrams of mifepristone resulted in a favorable cervix (with a Bishop score greater than 6 or in spontaneous labor) in significantly more women than placebo (P = .01). An improvement in cervical ripening was seen in the group given 50 mg of mifepristone, but this was not statistically significant. There were more cesarean deliveries performed for fetal distress in the group treated with 200 mg of mifepristone than placebo, but this was not statistically significant and was not associated with any differences between groups in terms of neonatal outcome.
                Mifepristone, a progesterone antagonist, is known to cause softening and dilation of the human early pregnant cervix and an increase in uterine activity. It is theoretically attractive for use as an adjunct in cervical priming and labor induction. In this study, 200 mg of mifepristone was significantly more likely to result in a favorable cervix than placebo. To determine the efficacy and safety of mifepristone as an induction agent for the initiation of labor or as a cervical ripening agent in women at term.
                Our study group contained 120 women at term (after 37.5 weeks' amenorrhea) who had clear clinical indications for labor induction. They were randomized to receive either 200 mg of mifepristone or placebo on days 1 and 2 of a 4-day observation period, with labor induction planned for day 4. Eight patients, three treated with mifepristone and five receiving placebo, had to be excluded from the survey because they required cesareans for medical reasons (fetal distress or maternal complications) less than 12 hours after taking the first tablet.
                Forty-one subjects entered spontaneous labor, 31 treated with mifepristone and ten in the control group (P < .001). Forty-five needed cervical maturation with prostaglandins on day 4, 13 of whom had received mifepristone and 32 of whom had been given placebo (P < .001). Thirteen women treated with mifepristone and 13 who had taken placebo had mature cervices sufficient for classic labor induction with oxytocin and amniotomy. Patients who delivered vaginally needed a much lower amount of oxytocin when mifepristone had been given, and the mean time interval between day 1 of the survey and the onset of labor was also significantly shorter in this group.
                Although more studies are needed, we have found mifepristone to be a safe, efficient, and suitable induction agent for initiation of labor in women at term. To determine the efficacy and safety of mifepristone for cervical ripening in post-term pregnancies.
                Women with post-term pregnancies and Bishop scores less than 6 were assigned randomly to mifepristone (41 patients) or placebo (42 patients). Mifepristone was given orally in a dose of 400 mg. Efficacy was assessed by change in the Bishop score within 48 hours after treatment; a score of 6 or greater was considered a "strict" success. An "extended" success rate was defined, including all patients with scores of at least 6 or those who delivered within 48 hours of treatment. Antenatal safety was assessed by fetal heart rate testing before and throughout labor. Neonatal safety was assessed by Apgar score, arterial or venous pH of cord blood, and blood glucose level during the first 48 hours. Analysis used Student t test for continuous variables, Kruskal-Wallis test for ordinal data, and chi2 for categoric variables.
                Strict success was achieved in 10 of 18 mifepristone patients (55%) evaluated for Bishop score on day 2 versus 8 of 29 placebo patients (27.5%) (P=.004). Extended success was achieved in 33 mifepristone patients (80.5%) and 21 placebo patients (50.0%) (P=.004). There were no statistical differences with regard to number of cesareans or fetal and neonatal safety.
                Mifepristone proved effective for cervical ripening and reduced the time to delivery compared with placebo, but it did not improve the rate of cesarean. Our study did not include enough pregnancies to reach conclusions about fetal or neonatal safety. To evaluate the efficacy of mifepristone in inducing labor in women with an unripe cervix, its effect on the cervix and on the status of the newborn.
                In a prospective double-blind study, 36 post-term pregnant women with a Bishop score of 5 or less received either 400 mg mifepristone (n=24) or placebo (n=12). If, 48 hours after the treatment was started, labor had not begun or the Bishop score was 5 or less, the women were given 0.5 mg prostaglandin E2 intracervically, a treatment which was repeated 12 hours later, if necessary.
                During the first 48 hours following treatment, 19 (79.2%) of the women treated with mifepristone and two of the women (16.7%) treated with placebo went into labor. In addition, one and three women, respectively, had a ripe cervix at the end of the 48h period. The overall success rate was thus 83.3% for mifepristone and 41.7% for placebo (p=0.008; OR 14.8; 95% CI 2.1-107.6). The median time from the start of treatment to delivery was also shorter (mifepristone 36h23' and placebo 53h17'). Treatment with intracervical PGE2 was needed more often after the placebo. The duration of labor, however, tended to be shorter after placebo than after mifepristone in the women who delivered vaginally. The frequencies of instrumental delivery were similar in both treatment groups. The median Apgar score was slightly lower at 1 minute (p<0.05) following mifepristone treatment, but did not differ at 5 and 10 minutes. There was no difference between the two treatment groups in the umbilical pH at delivery.
                The results of the present study show that mifepristone is a simple and effective treatment for inducing labor in post-term women with an unripe cervix. This study was undertaken to determine the efficacy of mifepristone for ripening the cervix and inducing labor in term pregnancies.
                In a double-blind placebo-controlled dose-finding study, 346 women received 50, 100, 200, 400, or 600 mg of mifepristone or placebo. The main endpoint for efficacy was the number of patients in whom labor occurred between 12 and 45 and 54 hours after treatment or who had a Bishop score 6 or greater. Maternal and fetal tolerability was also studied.
                No significant efficacy was observed whatever the dose of mifepristone. Mifepristone was well tolerated by the mother and fetus.
                Mifepristone, at doses up to 600 mg, does not induce labor within 54 hours in patients with unfavourable cervical status.
There is insufficient information available from clinical trials to support the use of mifepristone to induce labour. However, the studies suggest that mifepristone is better than placebo in reducing the likelihood of caesarean sections being performed for failed induction of labour; therefore, this may justify future trials comparing mifepristone with the routine cervical ripening agents currently in use. There is little information on effects on the baby.