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

Titrated oral misoprostol versus static regimen of oral misoprostol for induction of labour: a systematic review and meta-analysis

We aimed to conduct a systematic review and meta-analysis to compare the efficacy and safety of titrated oral misoprostol versus static oral misoprostol for labour induction. We searched for the available randomised clinical trials (RCTs) in the Cochrane Library, PubMed, ISI web of science, Scopus, and ClinicalTrials.gov. We included RCTs compared titrated oral misoprostol versus static regimen of oral misoprostol during labour induction. Our main outcomes were vaginal and caesarean delivery rates, uterine tachysystole, misoprostol side effects, and neonatal adverse events. Three RCTs met our inclusion criteria with a total number of 360 patients. The vaginal delivery rate did not significantly differ between both groups (p = 0.49). Titrated oral misoprostol was associated with significant increase in the caesarean delivery rate compared to static oral misoprostol (p = 0.04). Moreover, titrated oral misoprostol led to significant increase in the uterine tachysystole and misoprostol side effects (p = 0.01 & p = 0.003, respectively). There were no differences among both groups regarding different neonatal adverse events. In conclusion, titrated oral misoprostol increases the incidence of caesarean delivery, uterine tachysystole, and misoprostol side effects with a similar vaginal delivery rate compared to static dose misoprostol. Thus, static oral misoprostol should be used instead of titrated oral misoprostol during labour induction. Impact StatementWhat is already known on this subject? Different studies have evaluated titrated oral misoprostol administration for induction of labour and proved their efficacy in comparison with other induction methods. However, there is controversy among the published studies between titrated oral misoprostol and static oral misoprostol during induction of labour. A recent study concluded that hourly titrated misoprostol and static oral misoprostol are equally safe and effective when utilised for induction of labour with no fear of any adverse events. However, another study recommended static oral misoprostol administration for labour induction as it was linked to a lower caesarean section incidence, fewer drug side effects, and decline in complication rates in comparison with titrated oral misoprostol.What the results of this study add? Titrated oral misoprostol increases the incidence of caesarean delivery, uterine tachysystole, and misoprostol side effects with a similar vaginal delivery rate compared to static dose misoprostol.What the implications are of these findings for clinical practice and/or further research? Static oral misoprostol should be used instead of titrated oral misoprostol during labour induction. More future trials are required to confirm our findings.

Low-dose oral misoprostol for induction of labour

BACKGROUND

Misoprostol given orally is a commonly used labour induction method. Our Cochrane Review is restricted to studies with low-dose misoprostol (initially ≤ 50 µg), as higher doses pose unacceptably high risks of uterine hyperstimulation.

OBJECTIVES

To assess the efficacy and safety of low-dose oral misoprostol for labour induction in women with a viable fetus in the third trimester of pregnancy.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov,  the WHO International Clinical Trials Registry Platform (14 February 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials comparing low-dose oral misoprostol (initial dose ≤ 50 µg) versus placebo, vaginal dinoprostone, vaginal misoprostol, oxytocin, or mechanical methods; or comparing oral misoprostol protocols (one- to two-hourly versus four- to six-hourly; 20 µg to 25 µg versus 50 µg; or 20 µg hourly titrated versus 25 µg two-hourly static).

DATA COLLECTION AND ANALYSIS

Using Covidence, two review authors independently screened reports, extracted trial data, and performed quality assessments. Our primary outcomes were vaginal birth within 24 hours, caesarean section, and hyperstimulation with foetal heart changes.

MAIN RESULTS

We included 61 trials involving 20,026 women. GRADE assessments ranged from moderate- to very low-certainty evidence, with downgrading decisions based on imprecision, inconsistency, and study limitations. Oral misoprostol versus placebo/no treatment (four trials; 594 women) Oral misoprostol may make little to no difference in the rate of caesarean section (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.59 to 1.11; 4 trials; 594 women; moderate-certainty evidence), while its effect on uterine hyperstimulation with foetal heart rate changes is uncertain (RR 5.15, 95% CI 0.25 to 105.31; 3 trials; 495 women; very low-certainty evidence). Vaginal births within 24 hours was not reported. In all trials, oxytocin could be commenced after 12 to 24 hours and all women had pre-labour ruptured membranes. Oral misoprostol versus vaginal dinoprostone (13 trials; 9676 women) Oral misoprostol probably results in fewer caesarean sections (RR 0.84, 95% CI 0.78 to 0.90; 13 trials, 9676 women; moderate-certainty evidence). Subgroup analysis indicated that 10 µg to 25 µg (RR 0.80, 95% CI 0.74 to 0.87; 9 trials; 8652 women) may differ from 50 µg (RR 1.10, 95% CI 0.91 to 1.34; 4 trials; 1024 women) for caesarean section. Oral misoprostol may decrease vaginal births within 24 hours (RR 0.93, 95% CI 0.87 to 1.00; 10 trials; 8983 women; low-certainty evidence) and hyperstimulation with foetal heart rate changes (RR 0.49, 95% CI 0.40 to 0.59; 11 trials; 9084 women; low-certainty evidence). Oral misoprostol versus vaginal misoprostol (33 trials; 6110 women) Oral use may result in fewer vaginal births within 24 hours (average RR 0.81, 95% CI 0.68 to 0.95; 16 trials, 3451 women; low-certainty evidence), and less hyperstimulation with foetal heart rate changes (RR 0.69, 95% CI 0.53 to 0.92, 25 trials, 4857 women, low-certainty evidence), with subgroup analysis suggesting that 10 µg to 25 µg orally (RR 0.28, 95% CI 0.14 to 0.57; 6 trials, 957 women) may be superior to 50 µg orally (RR 0.82, 95% CI 0.61 to 1.11; 19 trials; 3900 women). Oral misoprostol probably does not increase caesarean sections overall (average RR 1.00, 95% CI 0.86 to 1.16; 32 trials; 5914 women; low-certainty evidence) but likely results in fewer caesareans for foetal distress (RR 0.74, 95% CI 0.55 to 0.99; 24 trials, 4775 women). Oral misoprostol versus intravenous oxytocin (6 trials; 737 women, 200 with ruptured membranes) Misoprostol may make little or no difference to vaginal births within 24 hours (RR 1.12, 95% CI 0.95 to 1.33; 3 trials; 466 women; low-certainty evidence), but probably results in fewer caesarean sections (RR 0.67, 95% CI 0.50 to 0.90; 6 trials; 737 women; moderate-certainty evidence). The effect on hyperstimulation with foetal heart rate changes is uncertain (RR 0.66, 95% CI 0.19 to 2.26; 3 trials, 331 women; very low-certainty evidence). Oral misoprostol versus mechanical methods (6 trials; 2993 women) Six trials compared oral misoprostol to transcervical Foley catheter. Misoprostol may increase vaginal birth within 24 hours (RR 1.32, 95% CI 0.98 to 1.79; 4 trials; 1044 women; low-certainty evidence), and probably reduces the risk of caesarean section (RR 0.84, 95% CI 0.75 to 0.95; 6 trials; 2993 women; moderate-certainty evidence). There may be little or no difference in hyperstimulation with foetal heart rate changes (RR 1.31, 95% CI 0.78 to 2.21; 4 trials; 2828 women; low-certainty evidence). Oral misoprostol one- to two-hourly versus four- to six-hourly (1 trial; 64 women) The evidence on hourly titration was very uncertain due to the low numbers reported. Oral misoprostol 20 µg hourly titrated versus 25 µg two-hourly static (2 trials; 296 women) The difference in regimen may have little or no effect on the rate of vaginal births in 24 hours (RR 0.97, 95% CI 0.80 to 1.16; low-certainty evidence). The evidence is of very low certainty for all other reported outcomes.

AUTHORS' CONCLUSIONS

Low-dose oral misoprostol is probably associated with fewer caesarean sections (and therefore more vaginal births) than vaginal dinoprostone, and lower rates of hyperstimulation with foetal heart rate changes. However, time to birth may be increased, as seen by a reduced number of vaginal births within 24 hours. Compared to transcervical Foley catheter, low-dose oral misoprostol is associated with fewer caesarean sections, but equivalent rates of hyperstimulation. Low-dose misoprostol given orally rather than vaginally is probably associated with similar rates of vaginal birth, although rates may be lower within the first 24 hours. However, there is likely less hyperstimulation with foetal heart changes, and fewer caesarean sections performed due to foetal distress. The best available evidence suggests that low-dose oral misoprostol probably has many benefits over other methods for labour induction. This review supports the use of low-dose oral misoprostol for induction of labour, and demonstrates the lower risks of hyperstimulation than when misoprostol is given vaginally. More trials are needed to establish the optimum oral misoprostol regimen, but these findings suggest that a starting dose of 25 µg may offer a good balance of efficacy and safety.

Safety and efficacy of titrated oral misoprostol solution versus vaginal dinoprostone for induction of labor: A single-center randomized control trial

Objective

To compare the efficacy and safety of the hourly administration of titrated oral misoprostol solution (OMS) and vaginal dinoprostone for induction of labor.

Methods

Titrated OMS was administrated hourly for induction of labor, starting with a dose of 20 µg and terminating at a dose of 50 µg. The safety and efficacy of OMS were compared with that of vaginal dinoprostone for induction of labor.

Results

From June 2016 to October 2019, 2280 (78.3%) and 2115 (72.9%) women who received titrated OMS and vaginal dinoprostone, respectively, had a vaginal delivery (P = 0.005). Cesarean delivery was performed in 632 (21.7%) and 783 (27.0%) women who received titrated OMS and vaginal dinoprostone, respectively (P = 0.008). Tachysystole with changes in fetal heart rate (FHR) was seen in 104 (3.6%) and 249 (8.6%) women in the OMS and dinoprostone groups, respectively (P = 0.007). The frequency of non‐reassuring FHR was lower in the OMS group compared to the dinoprostone group (P = 0.006).

Conclusion

The titrated OMS has an efficacy comparable to vaginal dinoprostone. Moreover, it causes a lower incidence of cesarean delivery, lower frequency of tachysystole with changes in FHR, and non‐reassuring FHR.

Titrated oral misoprostol has a similar efficacy to dinoprostone, but with a lower incidence of cesarean delivery and lower frequency of non‐reassuring fetal heart rate.

Challenges and Limitations of Clinical Trials on Labor Induction: A Review of the Literature

Induction of labor is a common obstetric procedure performed in nearly a quarter of all deliveries in the United States. Pharmacological (prostaglandins, oxytocin) and/or mechanical methods (balloon catheters) are commonly used for labor induction; however, there is ongoing debate as to which method is the safest and most effective. This narrative review discusses key limitations of published trials on labor induction, including the lack of well-designed randomized controlled trials directly comparing specific methods of induction, heterogeneous trial populations, and wide variation in the protocols used and outcomes reported. Furthermore, the majority of published trials were underpowered to detect significant differences in the most clinically relevant efficacy and safety outcomes (e.g., cesarean delivery, neonatal mortality). By identifying the limitations of labor induction trials, we hope to highlight the importance of quality published data to better inform guidelines and drive evidence-based treatment decisions.

Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour.

OBJECTIVE

To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups.

METHODS

We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group's Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012-13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves.

RESULTS

We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed 'best'. Few studies collected information on women's views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective.

LIMITATIONS

There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses.

CONCLUSIONS

Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention.

FUTURE WORK

Future trials should be powered to detect a method that is more cost-effective than misoprostol solution and report outcomes included in this NMA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Randomized clinical trial between hourly titrated and 2 hourly static oral misoprostol solution for induction of labor

BACKGROUND

Misoprostol is an effective agent for the induction of labor. Existing guidelines recommend oral misoprostol solution 25 μg every 2 hours. However, more research is required to optimize the use of oral misoprostol solution for the induction of labor.

OBJECTIVE

The purpose of this study was to compare efficacy and safety of hourly titrated-dose oral misoprostol solution with static-dose oral misoprostol solution every 2 hours for labor induction.

STUDY DESIGN

In this randomized controlled study, oral misoprostol solution was administered as (1) 20 μg hourly (≤4 doses) that was increased in the absence of regular uterine contractions to 40 μg hourly (≤4 doses) and then to 60 μg hourly (≤16 doses) or (2) 25 μg every 2 hours until active labor began (≤12 doses). A sample size of 146 women was planned with the use of a projected 95% rate for the primary endpoint (vaginal delivery within 24 hours) for hourly titrated-dose misoprostol and 80% rate for static-dose misoprostol every 2 hours. Safety outcomes included maternal morbidity and adverse neonatal outcomes.

RESULTS

From December 2013 to July 2015, 146 women were assigned randomly to treatment. Demographic and clinical factors were similar between groups, except for age. Vaginal delivery was achieved within 24 hours in 47 women (64.4%) who received hourly titrated-doses of misoprostol solution and 48 women (65.8%) who received 2-hourly static-dose misoprostol solution (P=1.00). Rates of vaginal delivery within 24 hours did not differ significantly between treatment groups for women who were nulliparous (P=1.00) or who had postterm pregnancies (P=.66), a Bishop score of ≤3 (P=.84), or oxytocin augmentation (P=.83). Cesarean deliveries were performed within 24 hours in 9 women who received hourly titrated-dose misoprostol solution and 2 women who received 2-hourly static-dose misoprostol solution (P=.056). Pyrexia and meconium-stained liquor occurred more frequently with the hourly titrated-dose regimen.

CONCLUSION

The static-dose oral misoprostol solution every 2 hours has similar efficacy as hourly titrated-dose misoprostol solution but with fewer side-effects and lower complication rates.

The use of misoprostol for cervical priming prior to hysteroscopy: a systematic review and analysis

The effects of misoprostol use on cervical priming prior to hysteroscopy have been controversial. Therefore, a systematic literature review and meta-analysis of studies were conducted to assess the effect of misoprostol on cervical priming prior to hysteroscopy. All studies published before July 2014 with data related to the use of misoprostol for cervical priming compared with placebo or no medication prior to hysteroscopy, were identified. Twenty-five randomized controlled trials involving 2,203 females were systematically analyzed. The results showed that, compared with placebo or no medication, the use of misoprostol prior to hysteroscopy led to a significant relief of the need for cervical dilatation, resulted in a significantly greater cervical width, had fewer hysteroscopy complications, and mild and insignificant side effects. Subgroup analyses revealed that the regimen of 200 or 400 μg vaginal misoprostol may be a simple and effective method for cervical priming, especially prior to operative hysteroscopy.

Comparative study of titrated oral misoprostol solution and vaginal dinoprostone for labor induction at term pregnancy

OBJECTIVE

To evaluate effectiveness and safety of titrated oral misoprostol solution (OMS) in comparison with vaginal dinoprostone for cervix ripening and labor induction in term pregnant women.

METHODS

A multicenter randomized controlled trial of women with term singleton pregnancy with indications for labor induction; 481 participants were allocated to receive titrated OMS with different doses by hourly administration according to the procedure or insert vaginal dinoprostone for cervix ripening and labor induction to compare maternal outcomes including indication of labor induction, mode of outcome of delivery, maternal morbidity, and neonatal outcomes between two groups for evaluating the efficacy and safety of titrated oral misoprostol induction.

RESULT

Proportion of delivery within 12 h of titrated oral misoprostol is significantly less than vaginal dinoprostone (p = 0.03), but no difference of total vaginal delivery rate (p = 0.93); the mean time of first treatment to vaginal delivery was longer in OMS group (21.3 ± 14.5 h) compared with the vaginal dinoprostone group (15.7 ± 9.6 h). Although the proportion of cesarean section between the two groups showed no statistically significant difference, OMS group showed significantly lower frequency of uterine hyperstimulation, hypertonus, partus precipitatus and non-reassuring fetal heart rate than dinoprostone group. Neonatal outcomes were similar evaluating from Apgar score and NICU admission. Our study also showed that labor induction of women with cervix Bishop score ≤3 needed increased dosage of misoprostol solution.

CONCLUSION

Titrated OMS is as effective as vaginal dinoprostone in labor induction for term pregnant women, with safer effect for its lower rate of adverse effect for women.

What is the optimal duration of oral misoprostol treatment for cervical ripening?

OBJECTIVES

To evaluate the number of misoprostol tablets needed to obtain a Bishop score (BS) ≥ 6 or a significant cervical change (≥2 points in BS) during cervical ripening.

METHODS

Retrospective study of women with term singleton pregnancies and a BS < 6 taking oral misoprostol (20 μg first 2 doses followed by 40 μg every 2 h) for cervical ripening.

RESULTS

We included 400 women, 72% nulliparous, mean age of 31.3 ± 5.9 years and 70% with a baseline BS ≤ 2. During cervical ripening, 61 (15.3%) achieved a BS ≥ 6 and 205 (51.3%) a significant change in BS. The incremental risk to achieve a BS ≥ 6 after 4 tablets was low (+3.25%) with an incremental probability of +12.75% for painful uterine contractions and +0.5% for abnormal fetal tracing (AFT). The incremental probability to achieve a significant change in BS after 7 tablets was low (+2.0%). 24.3% women delivered by cesarean section which likelihood significantly increased with maternal age <35 years, BMI ≥ 30, nulliparity, AFT, and baseline BS ≤ 2.

CONCLUSIONS

The marginal benefit of giving more than 7 misoprostol tablets (14 h) during cervical ripening is very low.

Oral misoprostol for induction of labour

BACKGROUND

Misoprostol is an orally active prostaglandin. In most countries misoprostol is not licensed for labour induction, but its use is common because it is cheap and heat stable.

OBJECTIVES

To assess the use of oral misoprostol for labour induction in women with a viable fetus.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 January 2014).

SELECTION CRITERIA

Randomised trials comparing oral misoprostol versus placebo or other methods, given to women with a viable fetus for labour induction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial data, using centrally-designed data sheets.

MAIN RESULTS

Overall there were 76 trials (14,412) women) which were of mixed quality.In nine trials comparing oral misoprostol with placebo (1109 women), women using oral misoprostol were more likely to give birth vaginally within 24 hours (risk ratio (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49; one trial; 96 women), need less oxytocin (RR 0.42, 95% CI 0.37 to 0.49; seven trials; 933 women) and have a lower caesarean section rate (RR 0.72, 95% CI 0.54 to 0.95; eight trials; 1029 women).In 12 trials comparing oral misoprostol with vaginal dinoprostone (3859 women), women given oral misoprostol were less likely to need a caesarean section (RR 0.88, 95% CI 0.78 to 0.99; 11 trials; 3592 women). There was some evidence that they had slower inductions, but there were no other statistically significant differences.Nine trials (1282 women) compared oral misoprostol with intravenous oxytocin. The caesarean section rate was significantly lower in women who received oral misoprostol (RR 0.77, 95% CI 0.60 to 0.98; nine trials; 1282 women), but they had increased rates of meconium-stained liquor (RR 1.65, 95% CI 1.04 to 2.60; seven trials; 1172 women).Thirty-seven trials (6417 women) compared oral and vaginal misoprostol and found no statistically significant difference in the primary outcomes of serious neonatal morbidity/death or serious maternal morbidity or death. The results for vaginal birth not achieved in 24 hours, uterine hyperstimulation with fetal heart rate (FHR) changes, and caesarean section were highly heterogenous - for uterine hyperstimulation with FHR changes this was related to dosage with lower rates in those with lower doses of oral misoprostol. However, there were fewer babies born with a low Apgar score in the oral group (RR 0.60, 95% CI 0.44 to 0.82; 19 trials; 4009 babies) and a decrease in postpartum haemorrhage (RR 0.57, 95% CI 0.34 to 0.95; 10 trials; 1478 women). However, the oral misoprostol group had an increase in meconium-stained liquor (RR 1.22, 95% CI 1.03 to 1.44; 24 trials; 3634 women).

AUTHORS' CONCLUSIONS

Oral misoprostol as an induction agent is effective at achieving vaginal birth. It is more effective than placebo, as effective as vaginal misoprostol and results in fewer caesarean sections than vaginal dinoprostone or oxytocin.Where misoprostol remains unlicensed for the induction of labour, many practitioners will prefer to use a licensed product like dinoprostone. If using oral misoprostol, the evidence suggests that the dose should be 20 to 25 mcg in solution. Given that safety is the primary concern, the evidence supports the use of oral regimens over vaginal regimens. This is especially important in situations where the risk of ascending infection is high and the lack of staff means that women cannot be intensely monitored.

Randomized clinical trial between hourly titrated oral misoprostol and vaginal dinoprostone for induction of labor

OBJECTIVE

The objective of the study was to compare the efficacy and safety of hourly titrated oral misoprostol with vaginal dinoprostone insert.

STUDY DESIGN

Subjects were randomized into hourly titrated oral misoprostol or dinoprostone 10 mg vaginal insert. Misoprostol was given as 20 μg hourly for 2 doses. In the absence of regular uterine contractions, the dose was increased to 30 μg hourly for 3 doses and then 40 μg for 1 dose, 50 μg for 1 dose, and 60 μg hourly for 4 doses. Before the 40 and 50 μg doses, 1 more hour of observation was given. The primary outcome variable was vaginal delivery within 24 hours. Safety assessments included the incidence of maternal morbidity and adverse neonatal outcomes.

RESULTS

A total of 160 women was enrolled in the study. The groups were similar for demographic and clinical factors. Vaginal delivery was achieved within 24 hours in 100 women (62.5%): 44 in the dinoprostone group (55.0%) and 56 in the misoprostol group (70.0%) (P = .05). The proportion of women who achieved vaginal delivery within 24 hours was significantly greater for nulliparous women in the misoprostol group (24 of 51, 58.5%) compared with the dinoprostone group (12 of 36, 33.3%; P = .0270). Significantly more women with baseline Bishop score of 3 or less in the misoprostol group had successful induction (43 of 59, 72.9%) compared with the dinoprostone group (27 of 60, 45.0%; P = .002). Frequencies of maternal adverse events were similar between groups.

CONCLUSION

Hourly titrated oral misoprostol can provide an efficacious and safe substitute for the expensive dinoprostone vaginal insert.

Titrated oral misoprostol for augmenting labour to improve maternal and neonatal outcomes

BACKGROUND

Labour dystocia is associated with a number of adverse maternal and neonatal outcomes. Augmentation of labour is a commonly used intervention in cases of labour dystocia. Misoprostol is an inexpensive and stable prostaglandin E1 analogue that can be administered orally, vaginally, sublingually or rectally. Misoprostol has proven to be effective at stimulating uterine contractions although it can have serious, and even life-threatening side-effects. Titration refers to the process of adjusting the dose, frequency, or both, of a medication on the basis of frequent review to achieve optimal outcomes. Studies have reported on a range of misoprostol titration regimens used for labour induction and titrated misoprostol may potentially be effective and safe for augmentation of labour.

OBJECTIVES

To examine the effects and safety of titrated oral misoprostol compared with placebo, oxytocin, other interventions, or no active treatment, in women with labour dystocia.

SEARCH METHODS

The Trials Search Co-ordinator of the Cochrane Pregnancy and Childbirth Group searched the Cochrane Pregnancy and Childbirth Group's Trials Register; date of search: 29 May 2013. We also searched the reference lists of retrieved studies

SELECTION CRITERIA

Randomised trials (including quasi-randomised and cluster-randomised trials) comparing titrated oral misoprostol with placebo, other interventions (e.g. oxytocin, other prostaglandins), or no treatment in women requiring augmentation of labour were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility for inclusion, carried out data extraction and assessed risk of bias in included studies. Data were entered by one author and checked for accuracy.

MAIN RESULTS

We included two randomised trials with a total of 581 women each comparing different regimens of titrated oral misoprostol with intravenous oxytocin. One study compared 20 mcg doses of misoprostol dissolved in water (repeated every hour up to four hours, after which the dose was increased to 40 mcg per hour up to a maximum total dose of 1600 mcg), while the second study gave women 75 mcg doses (repeated after four hours provided there were no adverse effects observed).Neither trial reported maternal death, severe maternal morbidity, or fetal/neonatal mortality outcomes, and only a few fetal/neonatal morbidity outcomes were considered, none of which were significantly different between groups. For several outcomes (such as maternal side-effects, instrumental birth, maternal blood transfusion for hypovolaemia and epidural analgesia), the number of events was generally too low for sufficient statistical power to be achieved. Maternal satisfaction was not reported in either trial. One trial reported a slight reduction in the median duration of labour from the start of augmentation to vaginal delivery in the oxytocin group.Neither trial reported significantly higher rates of caesarean section (CS) in the oral misoprostol group. Rates of vaginal delivery within 12 and 24 hours of commencing augmentation were not significantly different in the trial using a 20 mcg misoprostol dose. Neither trial had significantly higher rates of uterine hyperstimulation with fetal heart rate changes in the titrated oral misoprostol group. However, the rates of this outcome varied so greatly between the two studies as to suggest that other factors were at play. The only significant differences between groups related to uterine hyperstimulation (without fetal heart rate changes), and results were not consistent in the two trials. In the trial examining the higher dose of misoprostol, more women in the misoprostol group experienced hyperstimulation of labour measured over a 10-minute period compared with those receiving oxytocin (risk ratio (RR) 1.17, 95% confidence interval (CI) 1.02 to 1.35, 350 women). In the study examining the lower titrated dose of misoprostol, there was a lower incidence of tachysystole when labour was augmented with titrated oral misoprostol than with oxytocin (RR 0.39, 95% CI 0.17 to 0.91, 231 women) with no occurrences of hypertonus in either group of women.

AUTHORS' CONCLUSIONS

Important uncertainties still exist on the safety and acceptability of titrated oral misoprostol compared with intravenous oxytocin regimens in women with dystocia following spontaneous onset of labour. Although in facilities where electronic oxytocin infusion is not available, low-dose titrated misoprostol may offer a better alternative to an uncontrolled oxytocin infusion to avoid hyperstimulation. Further research is needed in both high- and low-resource settings More trials should be conducted to evaluate the effect of a standard titration oral misoprostol regimen, both following spontaneous labour and labour induction. Comparisons with other augmentation methods are also warranted, as are any effects on women's birth experiences.