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

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.

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.

Individualized misoprostol dosing for labor induction or augmentation: A review

Cesarean birth rates are greater than 20% in many developed countries. The main diagnoses contributing to the high rate of cesarean births in nulliparous women are dystocia and prolonged labor. Traditionally, a policy of vaginal dinoprostone for the treatment of unripe cervix or early amniotomy with oxytocin administration for a ripened cervix has been associated with a modest reduction in the rate of cesarean births due to arrest disorders. However, the course of vaginal dinoprostone is tedious and oxytocin should be administered through an infusion pump, which may be inconvenient in certain settings. Because misoprostol has powerful uterotropic and uterotonic effects, and has become a common agent used in the practice of obstetrics and gynecology, the United States Food and Drug Administration removed the absolute contraindication of the drug during pregnancy from its label in April 2002. However, excessive uterine contractility resulting in tachysystole or fetal distress is always a concern with the oral or vaginal use of fixed-dosage misoprostol. Therefore, misoprostol should be administered with caution to ensure that fetal hypoxia does not occur. A pilot trial examining the use of very small, frequent, titrated oral misoprostol dosages administered every 2 h was first conducted by Hofmeyr et al in 2001. Given women’s different metabolisms and responses to misoprostol, another method of titrating individualized oral misoprostol with dosing administered every hour relative to uterine response was then developed by Cheng in 2006. Based on previous studies, this titration method is potentially an ideal alternative to traditional dinoprostone, oxytocin or the previously established misoprostol dosing method for labor induction or augmentation.

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.

Titrated oral misoprostol solution versus vaginal misoprostol for labor induction

OBJECTIVE

To determine the efficacy and safety of a titrated oral misoprostol solution compared with vaginal misoprostol tablets for labor induction.

METHODS

A randomized, triple-blind, multicenter clinical trial was conducted between March 2010 and June 2011. Women with a single gestation (n=200) were randomized to receive a titrated oral misoprostol solution (initial misoprostol dose 20 μg/hour; dose increased by 20 μg/hour every 6 hours up to 80 μg/hour for a maximum of 48 doses) or vaginal misoprostol tablets (25 μg of misoprostol every 6 hours for a maximum of 8 doses). Risk ratios (RR) and 95% confidence intervals (CIs) were calculated for maternal and perinatal outcomes.

RESULTS

The frequencies of vaginal delivery not achieved within 12 hours (RR 0.87; 95% CI, 0.62-1.22) and within 24 hours (RR 1.11; 95% CI, 0.83-1.49) were similar in the 2 groups. No differences were found in terms of uterine hyperstimulation, unfavorable cervix at 12 and 24 hours, oxytocin augmentation, tachysystole, epidural analgesia, adverse effects, and perinatal outcome. Approximately 70% of the women preferred the oral solution.

CONCLUSION

A titrated oral misoprostol solution was as effective and safe for labor induction as vaginal misoprostol tablets. ClinicalTrial.gov: NCT00 992524.