Vaginal Misoprostol Administration for Cervical Ripening and Labor Induction

Comparative study of dinoprostone and misoprostol for induction of labor in patients with premature rupture of membranes after 35 weeks

The modalities of induction of labor in the event of premature rupture of membranes are controversial. The main purpose of this study was to compare the modalities of delivery after the use of dinoprostone or misoprostol for labor induction in the preterm rupture of membranes after 35 weeks in women with an unfavorable cervix. We then studied maternal and fetal morbidity for the two drugs. Retrospective, single-center, comparative cohort study in a level 3 maternity unit in France from 2009 to 2018 comparing vaginal administration of misoprostol 50 µg every six hours (maximum 150 µg) and administration of dinoprostone 10 mg, a slow-release vaginal insert, for 24 h (maximum 20 mg), for labor induction in the preterm rupture of membranes after 35 weeks in women with an unfavorable cervix (Bishop score < 6). We included 904 patients, 656 in the misoprostol group and 248 in the dinoprostone group. Vaginal delivery rate was significantly higher in the dinoprostone group (89% vs. 82%, p = 0.016). There were more cesarean sections for abnormal fetal heart rate in the misoprostol group (p = 0.005). The time interval from induction to the beginning of the active phase of labor and the duration of labor were shorter in the misoprostol group than in the dinoprostone group (437 min vs. 719 min, p < 0.001 and 335 min vs. 381 min, p = 0.0023, respectively). Maternal and neonatal outcomes were not significantly different in the two groups. Vaginal dinoprostone used for labor induction in preterm rupture of membranes seems to be more effective for vaginal delivery than vaginal misoprostol (50 µg).

Quality assessment of patient leaflets on misoprostol-induced labour: does written information adhere to international standards for patient involvement and informed consent?

OBJECTIVES

The need for thorough patient information is increasing as maternity care becomes more medicalised. The aim was to assess the quality of written patient information on labour induction. In most Danish hospitals, misoprostol is the first-choice drug for induction in low-risk pregnancies. Misoprostol has been associated with adverse side effects and severe outcomes for mother and child and is not registered for obstetric use in Denmark.

SETTING

Secondary care hospitals in Denmark.

DATA

Patient information leaflets from all hospitals that used misoprostol as an induction agent by June 2015 (N=13).

DESIGN

Patient leaflets were evaluated according to a validated scoring tool (International Patient Decision Aid Standards instrument, IPDAS), core elements in the Danish Health Act, and items regarding off-label use and non-registered medication. Two of the authors scored all leaflets independently.

OUTCOME MEASURES

Women's involvement in decision-making, information on benefits and harms associated with the treatment, other justifiable treatment options, and non-registered treatment.

RESULTS

Generally, the hospitals scored low on the IPDAS checklist. No hospitals encouraged women to consider their preferences. Information on side effects and adverse outcomes was poorly covered and varied substantially between hospitals. Few hospitals informed about precautions regarding outpatient inductions, and none informed about the lack of evidence on the safety of this procedure. None informed that misoprostol is not registered for induction or explained the meaning of off-label use or use of non-registered medication. Elements such as interprofessional consensus, long-term experience, and health authorities' approval were used to add credibility to the use of misoprostol.

CONCLUSIONS

Central criteria for patient involvement and informed consent were not met, and the patient leaflets did not inform according to current evidence on misoprostol-induced labour. Our findings indicate that patients receive very different, sometimes contradictory, information with potential ethical implications. Concerns should be given to outpatient inductions, where precise written information is of particular importance.

Comparing the effect of oral and vaginal isosorbide dinitrate in pre-induction cervical ripening in term pregnancy: A controlled clinical trial

Background:

Cervical ripening for labor induction is one of the most important issues in midwifery. Isosorbide dinitrate (ISDN) is one of the most important choices that have been proposed for cervical ripening, but still there are controversies regarding its prescription. The present study aimed to evaluate the effects of vaginal and oral ISDN compared to the control group for pre-induction cervical ripening.

Materials and Methods:

In this non-blinded clinical trial, 149 nulliparous women with term or prolonged pregnancy were randomly selected and divided into three groups by block randomization. The intervention group included vaginal (50 subjects, 40 mg) and oral (49 subjects, 20 mg) ISDN groups. The third group was the control group (50 subjects) which did not receive any medication. The amount of ripening was given by Bishop score evaluated before taking medication and 24 h after taking it.

Results:

After 24 h, Bishop score in vaginal ISDN group significantly increased compared to the oral ISDN and control groups (P < 0.001 for both). Although the increase in Bishop score was lower in the oral ISDN group than in the vaginal group, it had a statistically significant increase in comparison to the control group (P = 0.001). All the three groups were matched regarding pregnancy termination and cesarean causes, and there was no statistically significant difference among the three groups (P > 0.05).

Conclusion:

Prescribing vaginal ISDN for cervical ripening was effective, and it can be used with confidence.

Is low dose vaginal misoprostol better than dinoprostone gel for induction of labor: a randomized controlled trial

OBJECTIVE

To compare the efficacy and safety profile of low dose vaginal misoprostol with dinoprostone gel for induction of labor in term pregnancies.

METHODS

The study was conducted at Lady Hardinge Medical College and Smt Sucheta Kriplani Hospital on 100 pregnant women with term pregnancy after application of inclusion and exclusion criteria. The women were randomized in 2 groups of 50 women each. Group I received misoprostol 25μg at every six hour vaginally for a maximum of five doses for induction of labor; while group II received dinoprostone gel 0.5 mg every six hourly for a maximum of three doses. Maternal outcomes such as mode of delivery and induction delivery interval; and fetal outcomes such as APGAR score and incidence of NICU admission were assessed in both the groups. Statistical analysis was done using student t-test and chi-square test.

RESULTS

There was no significant difference in the mean induction to delivery interval in both the groups (14.32±0.13 hours in Group I and 14.92±0.18 hours in Group II, p=0.75), mode of delivery, indication of cesarean section and perinatal outcome. However, significant difference was observed in requirement of oxytocin augmentation in both the groups (32% in Group I and 68% in Group II, p=0.005).

CONCLUSION

Vaginal misoprostol in low doses is similar in efficacy and safety to dinoprostone gel for cervical ripening and labor induction in term pregnancy.

The pharmacology of prostaglandins for induction of labor

Prostaglandin medications are frequently used in the process of induction of labor. Understanding the history and research that supports prostaglandin use for induction of labor is crucial for safe practice. Dinoprostone has been the standard of care for cervical ripening in term pregnancies. Misoprostol administration via various routes has been shown to be efficacious. Oral misoprostol in particular is effective and associated with reassuring maternal and fetal outcomes. In addition, cost has become a variable in decision making regarding best practice. More research is necessary to determine the safest medication, route, dose, and interval of administration. This article reviews cervical physiology and endogenous prostaglandin activity in relation to labor, and the pharmacologic profiles of synthetic prostaglandins currently used for induction of labor.

Comparison of the efficacy and safety of titrated oral misoprostol and a conventional oral regimen for cervical ripening and labor induction

OBJECTIVE

To compare the efficacy and safety of titrated oral misoprostol and a conventional oral regimen for cervical ripening and labor induction.

METHODS

A randomized double-blind trial of women with term singleton pregnancies with indications for labor induction. Participants were allocated to receive 20 mL of misoprostol solution (1 μg/mL) orally every 1 hour for 4 doses then titrated to 40 μg every 1 hour (titrated group) or 50 μg of misoprostol orally every 4 hours up to 12 hours (conventional group). Primary outcomes were success rate of cervical ripening within 12 hours, interval from first dose until more favorable cervix or active labor occurred, and total dose of misoprostol.

RESULTS

Sixty-four participants were included. Mean total dose of misoprostol and incidence of tachysystole were significantly higher in the titrated compared with the conventional group (236.2±110.1 μg vs 103.1 ± 35.7 μg; P=0.001 and 25.0% vs 6.3%; P=0.03), whereas success rate, interval from drug administration to more favorable cervix and delivery, proportion of patients delivered vaginally within 12 hours and 24 hours, need for oxytocin augmentation, cesarean delivery rate, maternal adverse effects and complications, and neonatal outcome were not significantly different (P>0.05).

CONCLUSION

Conventional oral misoprostol is as effective as titrated misoprostol for cervical ripening and labor induction, but has a lower incidence of tachysystole and a lower total dose of misoprostol is required. ClinicalTrial.gov: NCT00886860.

Comparison of labor induction with titrated oral misoprostol solution between nulliparous and multiparous women

AIM

To compare the outcomes of labor induction with oral misoprostol solution between nulliparous and multiparous women.

METHODS

We retrospectively reviewed the medical records of all patients between 37 and 42 weeks of gestation with a Bishop score <or=6 who underwent labor induction with titrated oral misoprostol solution. The women were allocated into two groups: nulliparous and multiparous. The women received one basal unit of misoprostol solution (20 mL, 1 microg/mL) every hour for four doses; additional doses were titrated against individual uterine response. The interval of latent and active phase and vaginal delivery within 12 h were the primary outcomes.

RESULTS

Of the 112 women included in the study, 49 (43.8%) mulliparae and 63 (56.2%) multiparae underwent labor induction with titrated oral misoprostol solution. Complete vaginal delivery occurred within 12 h in 21 (42.9%) nulliparae and 54 (85.7%) multiparae (RR, 0.54; 95% CI, 0.39-0.76). All induction intervals, including the latent and active phases, were significantly shorter in the multiparous group (P < 0.01). Induction failure did not occur in any patient in either of the groups. There were no instances of hyperstimulation, which was defined as tachysystole or hypertonus with nonreassuring fetal heart rate pattern, although tachysystole, defined as the presence of at least six contractions in 10 min over at least two 10-min windows, occurred in four (8.2%) nulliparous women and in four (6.3%) multiparous women. Hypertonus, defined as a single contraction lasting more than 2 min, did not occur in either group. None of the neonates in either group had an Apgar score of <7 at 1 min.

CONCLUSION

Titrated oral misoprostol solution is a promising method of labor induction for both nulliparous and multiparous women.

A randomised controlled trial of intravaginal dinoprostone, intravaginal misoprostol and transcervical balloon catheter for labour induction

OBJECTIVE

To compare the efficacy and safety of induction of labour by vaginal application of dinoprostone or misoprostol or transcervical insertion of a balloon (Bard) catheter.

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level Swedish hospital.

POPULATION

A total of 592 women who had undergone full-term pregnancies, not previously been subjected to a caesarean section, and required induction of labour for common, routine indications.

METHODS

Women were randomly assigned to induction of labour using intravaginal dinoprostone (2 mg once every 6 hours) or misoprostol (25 micrograms once every 4 hours) or a transcervical balloon catheter.

MAIN OUTCOME MEASURES

The time interval between induction to delivery in general and vaginal delivery in particular, the mode of delivery, maternal and neonatal parameters of outcome.

RESULTS

Of the 588 subjects included in the final intention-to-treat analysis, 191 were assigned to treatment with dinoprostone, 199 with misoprostol and 198 with the balloon catheter. The shortest mean induction-to-delivery interval was obtained with the catheter (12.9 hours versus 16.8 and 17.3 hours for dinoprostone and misoprostol, respectively). The efficacies of the two prostaglandins were similar. The maternal and neonatal outcomes associated with each of the three procedures were similar.

CONCLUSIONS

Induction of labour with a transcervical balloon catheter is effective and safe and can be recommended as the first choice. The two prostaglandins, dinoprostone and misoprostol, were shown to be equally effective and safe, while misoprostol costs significantly less and is easier to store.

Titrated oral compared with vaginal misoprostol for labor induction: a randomized controlled trial

OBJECTIVE

To compare the efficacy and safety of titrated oral misoprostol and vaginal misoprostol for labor induction.

METHODS

Women between 34 and 42 weeks of gestation with an unfavorable cervix (Bishop score less than or equal to 6) and an indication for labor induction were randomLy assigned to receive titrated oral or vaginal misoprostol. The titrated oral misoprostol group received a basal unit of 20 mL misoprostol solution (1 mcg/mL) every 1 hour for four doses and then were titrated against individual uterine response. The vaginal group received 25 mcg every 4 hours until attaining a more favorable cervix. Vaginal delivery within 12 hours was the primary outcome. The data were analyzed by intention-to-treat.

RESULTS

Titrated oral misoprostol was given to 101 (48.8%) women and vaginal misoprostol to 106 (51.2%) women. Completed vaginal delivery occurred within 12 hours in 75 (74.3%) women in the titrated oral group and 27 (25.5%) women in the vaginal group (relative risk [RR] 8.44, 95% confidence interval [CI] 4.52-15.76). The incidence of hyperstimulation was 0.0% in the titrated oral group compared with 11.3% in the vaginal group (RR 0.08, 95% CI 0.01-0.61). Although more women experienced nausea (10.9%) in the titrated oral group (RR 27.07, 95% CI 1.57-465.70), fewer infants had Apgar scores of less than 7 at 1 minute in the titrated oral group than in the vaginal group (RR 0.10, 95% CI 0.01-0.76).

CONCLUSION

Titrated oral misoprostol is associated with a lower incidence of uterine hyperstimulation and a lower cesarean delivery rate than vaginal misoprostol for labor induction in patients with unfavorable cervix.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00529295

LEVEL OF EVIDENCE

I.

Cervical preparation for second-trimester surgical abortion prior to 20 weeks of gestation

Roughly 11% of induced abortions in the United States are performed after 14 weeks of gestation, most commonly by dilation and evacuation (D&E). For a D&E procedure, the cervix must be dilated sufficiently to allow passage of operative instruments and products of conception without injuring the uterus or cervical canal. Preoperative preparation of the cervix reduces the risk of cervical laceration and uterine perforation. The cervix may be prepared with osmotic dilators, prostaglandin analogues, or both. Osmotic dilators currently available in the United States include Dilapan-S, Lamicel, and laminaria. Laminaria tents are made from dehydrated seaweed and require 12-24 h to achieve greatest dilation. The synthetic products, Dilapan-S and Lamicel, achieve maximum effect within 6 h. Dilapan-S achieves greater dilation than the others and, thus, requires fewer dilators to be placed but may be more difficult to remove. For same day procedures, Dilapan-S and Lamicel are preferable to laminaria. A single set of one to several dilators is usually adequate for D&E before 20 weeks of gestation. Additional sets over 1-2 days may be needed in challenging cases. Misoprostol, a prostaglandin analogue, is sometimes used instead of osmotic dilators; however, the data to support such use are limited. Misoprostol is inferior to overnight dilation with laminaria for cervical priming prior to D&E. Misoprostol use as an adjunct to overnight osmotic dilation is only marginally beneficial for priming beyond 16 weeks and does not truly demonstrate any benefit before 19 weeks of gestation. Limited data demonstrate the safety of misoprostol prior to D&E in patients with a uterine scar. The Society of Family Planning recommends preoperative cervical preparation to decrease the risk of complications when performing a D&E prior to 20 weeks of gestation. The three currently available osmotic dilators (laminaria, Lamicel, and Dilapan-S) are safe and effective for this use. Since no single protocol has been found to be superior, clinical judgment is warranted when selecting a method of preoperative cervical preparation.