Labor Progress Varies With Foley vs Misoprostol Induction

May 22, 2013

By Will Boggs, MD

NEW YORK (Reuters Health) May 22 - Labor lasts just as long after induction with a Foley catheter or misoprostol, but the patterns of progress differ, a retrospective study suggests.

With the catheter, there's quick early progress that slows. With misoprostol, progress is slow at first and then speeds up, according to Dr. Methodius G. Tuuli and colleagues from Washington University School of Medicine in St. Louis, Missouri.

They compared the duration and progress of labor in 503 women induced with misoprostol and 114 induced with a Foley catheter. All were carrying singletons at term, with vertex presentations.

Total duration of labor (cervical dilation from 1 to 10 cm) did not differ between the misoprostol and Foley groups (12.0 vs 14.2 hours; p=0.19), according to a report May 8th online in the American Journal of Obstetrics and Gynecology.

However, women induced with the Foley catheter progressed more rapidly from 1 to 4 cm (3.4 vs 5.6 hours; p<0.01), whereas women induced with misoprostol progressed more rapidly from 4 to 10 cm (3.6 vs 6.3 hours; p<0.01).

Moreover, the transition from latent to active labor occurred when the cervix was roughly 4 cm dilated in the misoprostol group and at roughly 6 cm for the Foley group.

In subgroup analyses of nulliparous and multiparous women, patterns of labor progress were similar to those in the overall cohort, although the duration of labor was shorter among multiparous women induced with misoprostol than with a Foley catheter (11.7 vs 17.1 hours; p=0.03).

"These differences should be considered in the management of labor induced with the two methods," the researchers conclude. "Based on these findings, we recommend that diagnosis of failed induction of labor be made with caution prior to 6 cm cervical dilation, especially in women induced with the Foley catheter."

"The article shows no difference in the induction to delivery interval between the two methods," Dr. Mohamed Kandil, Professor of Obstetrics and Gynecology at Menofyi University, Egypt told Reuters Health. "However; this is a retrospective study liable to bias especially because the assignment of women into either group was based solely on the admitting physician."

"As a rule," Dr. Kandil said, "findings of retrospective studies should not be taken into consideration to change how labor is managed. Such changes should be based only on well designed randomized controlled trials."

Dr. Kandil favors the Foley catheter. "Foley catheter has no complications when compared to misoprostol, which may lead to complications such as tachysystole, hypertonus, uterine rupture, and increased C-section rate," he said. "Furthermore, the Foley has advantages (such) as the possibility of being used in women with previous cesarean, a contraindication for the use of misoprostol. It is also of low cost and lacks systemic side effects."

Dr. Kitty W. M. Bloemenkamp, Maternal Fetal Medicine Specialist from Leiden University Medical Center, Leiden, The Netherlands, advises, "Don't be in a hurry when inducing labor."

She told Reuters Health, "The main goal of labor induction is a safe and uncomplicated delivery for mother and child. When comparing different methods of induction of labor, effectiveness, safety, costs, and patient preference have to be taken into account. Unfortunately, the study of Tuuli et al did not investigate any maternal or neonatal outcomes, and therefore their study cannot answer this question."

"We recently showed that the use of a Foley catheter, in term women with an unfavorable cervix, resulted in equal vaginal delivery rates when compared to vaginal Prostaglandin E2 gel," Dr. Bloemenkamp said. "And a meta-analysis showed lower rates of hyperstimulation, resulting in less asphyxia and postpartum hemorrhage. For the comparison of the Foley catheter with prostaglandin E1 preparations, we have to await the results of ongoing randomized controlled trials.

Dr. Tuuli did not respond to a request for comments on this report.


Am J Obstet Gynecol 2013.


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