Induction of labor using one dose vs multiple doses of misoprostol

a randomized controlled trial

Verónica Maria Pimentel, Moona Arabkhazaeli, Jee Young Moon, Alexander Wang, Arisa Kapedani, Peter S. Bernstein, Pamela J. Tropper

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Background: Misoprostol is a common agent that is used to ripen the cervix and induce labor, yet there is no clear evidence of the optimal number of doses needed to achieve a higher rate of vaginal delivery. Objective: Our primary objective was to compare the rate of vaginal delivery within 24 hours between a 1-dose and a multiple-dose regimen of misoprostol for the induction of labor. Study Design: A randomized controlled trial was conducted from March 2016 to March 2017 that compared a single dose to up to 4 doses of misoprostol. Randomization was stratified by parity. Women with a singleton pregnancy ≥37 weeks gestation with intact membranes who had been admitted for labor induction with a Bishop score ≤6 were included. Our primary outcome was the rate of vaginal delivery within 24 hours. Secondary outcomes included time to vaginal delivery, cesarean delivery rate, and maternal and neonatal morbidity. Based on a power of 80%, an alpha of.05, and the assumption that 50% of women in the multiple-misoprostol group would deliver vaginally in 24 hours, a sample size of 220 patients was needed to detect a 20% increase in vaginal delivery rate within 24 hours in the 1-misoprostol group. Continuous variables were compared with the use of the Mann-Whitney test. Categoric variables were compared with the use of the Fisher's exact test. Probability values <.05 were considered statistically significant. Results: Two hundred fifty women were assigned randomly. Demographics and clinical characteristics were similar between groups. In the univariate analysis, there was no difference in the rate of vaginal delivery within 24 hours between the 1-misoprostol group and the multiple-dose group (41.7% vs 44.7%, respectively; P=.698) or time to vaginal delivery (1187 min vs 1321 min, respectively; P=.202). The 1-misoprostol group had a greater cesarean delivery rate (35.8% vs 22.8%; P=.034). In a Poisson regression that controlled for Bishop score before the initiation of oxytocin, parity, gestational age, body mass index, estimated fetal weight, artificial rupture of membrane at <6 cm, and Foley balloon placement, the treatment group was no longer associated with cesarean delivery rate. Instead, a Bishop score of <4 before the initiation of oxytocin and nulliparity were associated significantly with cesarean delivery rate. Conclusion: In this first randomized controlled trial in the literature to compare a single with a multiple dosing of misoprostol, we found that the 1-dose regimen is an acceptable alternative for the induction for labor, especially for multiparous women and for patients with a Bishop score >4 after the first dose.

Original languageEnglish (US)
JournalAmerican Journal of Obstetrics and Gynecology
DOIs
StateAccepted/In press - Jan 1 2018

Fingerprint

Induced Labor
Misoprostol
Randomized Controlled Trials
Pregnancy
Random Allocation
Parity
Cervix Uteri
Sample Size
Mothers
Morbidity
Membranes

Keywords

  • cesarean delivery
  • induction of labor
  • misoprostol
  • oxytocin
  • vaginal delivery rate

ASJC Scopus subject areas

  • Obstetrics and Gynecology

Cite this

Induction of labor using one dose vs multiple doses of misoprostol : a randomized controlled trial. / Pimentel, Verónica Maria; Arabkhazaeli, Moona; Moon, Jee Young; Wang, Alexander; Kapedani, Arisa; Bernstein, Peter S.; Tropper, Pamela J.

In: American Journal of Obstetrics and Gynecology, 01.01.2018.

Research output: Contribution to journalArticle

@article{5a7ff10645684d5f92114bd91c84f208,
title = "Induction of labor using one dose vs multiple doses of misoprostol: a randomized controlled trial",
abstract = "Background: Misoprostol is a common agent that is used to ripen the cervix and induce labor, yet there is no clear evidence of the optimal number of doses needed to achieve a higher rate of vaginal delivery. Objective: Our primary objective was to compare the rate of vaginal delivery within 24 hours between a 1-dose and a multiple-dose regimen of misoprostol for the induction of labor. Study Design: A randomized controlled trial was conducted from March 2016 to March 2017 that compared a single dose to up to 4 doses of misoprostol. Randomization was stratified by parity. Women with a singleton pregnancy ≥37 weeks gestation with intact membranes who had been admitted for labor induction with a Bishop score ≤6 were included. Our primary outcome was the rate of vaginal delivery within 24 hours. Secondary outcomes included time to vaginal delivery, cesarean delivery rate, and maternal and neonatal morbidity. Based on a power of 80{\%}, an alpha of.05, and the assumption that 50{\%} of women in the multiple-misoprostol group would deliver vaginally in 24 hours, a sample size of 220 patients was needed to detect a 20{\%} increase in vaginal delivery rate within 24 hours in the 1-misoprostol group. Continuous variables were compared with the use of the Mann-Whitney test. Categoric variables were compared with the use of the Fisher's exact test. Probability values <.05 were considered statistically significant. Results: Two hundred fifty women were assigned randomly. Demographics and clinical characteristics were similar between groups. In the univariate analysis, there was no difference in the rate of vaginal delivery within 24 hours between the 1-misoprostol group and the multiple-dose group (41.7{\%} vs 44.7{\%}, respectively; P=.698) or time to vaginal delivery (1187 min vs 1321 min, respectively; P=.202). The 1-misoprostol group had a greater cesarean delivery rate (35.8{\%} vs 22.8{\%}; P=.034). In a Poisson regression that controlled for Bishop score before the initiation of oxytocin, parity, gestational age, body mass index, estimated fetal weight, artificial rupture of membrane at <6 cm, and Foley balloon placement, the treatment group was no longer associated with cesarean delivery rate. Instead, a Bishop score of <4 before the initiation of oxytocin and nulliparity were associated significantly with cesarean delivery rate. Conclusion: In this first randomized controlled trial in the literature to compare a single with a multiple dosing of misoprostol, we found that the 1-dose regimen is an acceptable alternative for the induction for labor, especially for multiparous women and for patients with a Bishop score >4 after the first dose.",
keywords = "cesarean delivery, induction of labor, misoprostol, oxytocin, vaginal delivery rate",
author = "Pimentel, {Ver{\'o}nica Maria} and Moona Arabkhazaeli and Moon, {Jee Young} and Alexander Wang and Arisa Kapedani and Bernstein, {Peter S.} and Tropper, {Pamela J.}",
year = "2018",
month = "1",
day = "1",
doi = "10.1016/j.ajog.2018.03.034",
language = "English (US)",
journal = "American Journal of Obstetrics and Gynecology",
issn = "0002-9378",
publisher = "Mosby Inc.",

}

TY - JOUR

T1 - Induction of labor using one dose vs multiple doses of misoprostol

T2 - a randomized controlled trial

AU - Pimentel, Verónica Maria

AU - Arabkhazaeli, Moona

AU - Moon, Jee Young

AU - Wang, Alexander

AU - Kapedani, Arisa

AU - Bernstein, Peter S.

AU - Tropper, Pamela J.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Background: Misoprostol is a common agent that is used to ripen the cervix and induce labor, yet there is no clear evidence of the optimal number of doses needed to achieve a higher rate of vaginal delivery. Objective: Our primary objective was to compare the rate of vaginal delivery within 24 hours between a 1-dose and a multiple-dose regimen of misoprostol for the induction of labor. Study Design: A randomized controlled trial was conducted from March 2016 to March 2017 that compared a single dose to up to 4 doses of misoprostol. Randomization was stratified by parity. Women with a singleton pregnancy ≥37 weeks gestation with intact membranes who had been admitted for labor induction with a Bishop score ≤6 were included. Our primary outcome was the rate of vaginal delivery within 24 hours. Secondary outcomes included time to vaginal delivery, cesarean delivery rate, and maternal and neonatal morbidity. Based on a power of 80%, an alpha of.05, and the assumption that 50% of women in the multiple-misoprostol group would deliver vaginally in 24 hours, a sample size of 220 patients was needed to detect a 20% increase in vaginal delivery rate within 24 hours in the 1-misoprostol group. Continuous variables were compared with the use of the Mann-Whitney test. Categoric variables were compared with the use of the Fisher's exact test. Probability values <.05 were considered statistically significant. Results: Two hundred fifty women were assigned randomly. Demographics and clinical characteristics were similar between groups. In the univariate analysis, there was no difference in the rate of vaginal delivery within 24 hours between the 1-misoprostol group and the multiple-dose group (41.7% vs 44.7%, respectively; P=.698) or time to vaginal delivery (1187 min vs 1321 min, respectively; P=.202). The 1-misoprostol group had a greater cesarean delivery rate (35.8% vs 22.8%; P=.034). In a Poisson regression that controlled for Bishop score before the initiation of oxytocin, parity, gestational age, body mass index, estimated fetal weight, artificial rupture of membrane at <6 cm, and Foley balloon placement, the treatment group was no longer associated with cesarean delivery rate. Instead, a Bishop score of <4 before the initiation of oxytocin and nulliparity were associated significantly with cesarean delivery rate. Conclusion: In this first randomized controlled trial in the literature to compare a single with a multiple dosing of misoprostol, we found that the 1-dose regimen is an acceptable alternative for the induction for labor, especially for multiparous women and for patients with a Bishop score >4 after the first dose.

AB - Background: Misoprostol is a common agent that is used to ripen the cervix and induce labor, yet there is no clear evidence of the optimal number of doses needed to achieve a higher rate of vaginal delivery. Objective: Our primary objective was to compare the rate of vaginal delivery within 24 hours between a 1-dose and a multiple-dose regimen of misoprostol for the induction of labor. Study Design: A randomized controlled trial was conducted from March 2016 to March 2017 that compared a single dose to up to 4 doses of misoprostol. Randomization was stratified by parity. Women with a singleton pregnancy ≥37 weeks gestation with intact membranes who had been admitted for labor induction with a Bishop score ≤6 were included. Our primary outcome was the rate of vaginal delivery within 24 hours. Secondary outcomes included time to vaginal delivery, cesarean delivery rate, and maternal and neonatal morbidity. Based on a power of 80%, an alpha of.05, and the assumption that 50% of women in the multiple-misoprostol group would deliver vaginally in 24 hours, a sample size of 220 patients was needed to detect a 20% increase in vaginal delivery rate within 24 hours in the 1-misoprostol group. Continuous variables were compared with the use of the Mann-Whitney test. Categoric variables were compared with the use of the Fisher's exact test. Probability values <.05 were considered statistically significant. Results: Two hundred fifty women were assigned randomly. Demographics and clinical characteristics were similar between groups. In the univariate analysis, there was no difference in the rate of vaginal delivery within 24 hours between the 1-misoprostol group and the multiple-dose group (41.7% vs 44.7%, respectively; P=.698) or time to vaginal delivery (1187 min vs 1321 min, respectively; P=.202). The 1-misoprostol group had a greater cesarean delivery rate (35.8% vs 22.8%; P=.034). In a Poisson regression that controlled for Bishop score before the initiation of oxytocin, parity, gestational age, body mass index, estimated fetal weight, artificial rupture of membrane at <6 cm, and Foley balloon placement, the treatment group was no longer associated with cesarean delivery rate. Instead, a Bishop score of <4 before the initiation of oxytocin and nulliparity were associated significantly with cesarean delivery rate. Conclusion: In this first randomized controlled trial in the literature to compare a single with a multiple dosing of misoprostol, we found that the 1-dose regimen is an acceptable alternative for the induction for labor, especially for multiparous women and for patients with a Bishop score >4 after the first dose.

KW - cesarean delivery

KW - induction of labor

KW - misoprostol

KW - oxytocin

KW - vaginal delivery rate

UR - http://www.scopus.com/inward/record.url?scp=85046164152&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85046164152&partnerID=8YFLogxK

U2 - 10.1016/j.ajog.2018.03.034

DO - 10.1016/j.ajog.2018.03.034

M3 - Article

JO - American Journal of Obstetrics and Gynecology

JF - American Journal of Obstetrics and Gynecology

SN - 0002-9378

ER -