Titrated oral misoprostol solution compared with intravenous oxytocin for labor augmentation: a randomized controlled trial. Obstet Gynecol. 2010;116:612-618. [PMID: 20733443 DOI: 10.1097/aog.0b013e3181ed36cc]

Association of oxytocin augmentation with postpartum hemorrhage: a systematic review and meta-analysis

OBJECTIVE

The current study aims to evaluate the correlation between oxytocin augmentation and postpartum hemorrhage.

METHOD

PubMed, Web of Science, and Scopus has been searched for studies assessing the correlation between oxytocin augmentation and postpartum hemorrhage up to January 24, 2024. The search strategy included relevant keywords related to PPH and oxytocin augmentation. The risk of bias assessment was conducted by two reviewers using the Newcastle-Ottawa Scale (NOS). To pool the effects sized of included studies odds ratios (OR) of interest outcome with their 95% confidence interval (CI) were used.

RESULTS

Eight studies were included in this meta-analysis. The pooled analysis of the included studies showed a statistically significant association between oxytocin augmentation and increased odds of PPH (pooled odds ratio [OR] = 1.27, 95% confidence interval [CI]: 1.05-1.53; I2 = 84.94%; p = 0.01). Publication bias was assessed using funnel plots, which appeared relatively asymmetrical, indicating significant publication bias. Galbraith plot and trim and fill plot were used for publication bias. Sensitivity analyses were performed by leave one out method.

CONCLUSION

This meta-analysis suggests that using oxytocin for labor augmentation is linked to a significant increase in the risk of PPH. It highlights the need for careful monitoring and consideration when using oxytocin, especially in low and middle-income countries where guidelines and supervision are crucial.

Effect of misoprostol versus oxytocin on delivery outcomes after labour induction in pregnant women: A systematic review and meta-analysis of randomized controlled trials

A large number of randomized controlled trials (RCTs) have been published on the effects of oral/vaginal misoprostol and oxytocin on delivery outcomes; however, data from these RCTs are conflicting. Although some meta-analyses summarized available findings in this regard, several eligible RCTs have been published since the release of those meta-analyses. Therefore, the current updated systematic review and meta-analysis of RCTs was conducted to compare the effects of oral/vaginal misoprostol and oxytocin on delivery and neonatal outcomes. A systematic search, using relevant keywords, was done in the online databases of PubMed/Medline, Scopus, and ISI Web of Science, up to April 2023, to identify eligible articles investigating the effect of oral/vaginal misoprostol and oxytocin on delivery outcomes including maternal [cesarean/vaginal delivery within 24 h after labour induction, Tachysystole, hypertonicity, hyper-stimulation, postpartum hemorrhage (PPH)] and neonatal outcomes [mean Apgar score, admission to neonatal intensive care unit (NICU), and death]. In total, 45 RCTs with a total sample size of 8406 participants were included. Meta-analysis revealed that vaginal misoprostol administration, compared with oxytocin, resulted in a significant reduction in the rate of cesarean and a significant increase in the rate of vaginal delivery and Tachysystole risk. Also, oral misoprostol was associated with a significant reduction in the rate of cesarean and a significant increase in the risk of hypertonicity compared with oxytocin. However, oral misoprostol had no significant effect on vaginal delivery compared with oxytocin. For other outcomes including hyper-stimulation, perinatal death, NICU admission, and mean Apgar score among newborns, we found no significant difference between oral/vaginal misoprostol and oxytocin. In total, vaginal/oral misoprostol might be a better method for labour induction compared with oxytocin. PROSPERO registration: CRD42023412325.

Efficacy comparison of titrated oral solution of misoprostol and intravenous oxytocin on labour induction in women with full-term pregnancy

A double-blind randomised trial was conducted on women with gestational age of 40-42 weeks of pregnancy and Bishop score of more than 5. The first group received oxytocin infusion and the second group received a titrated oral solution of misoprostol. Then, the two groups were compared by the primary outcome (the number of deliveries in the first 24 hours of intervention). The two groups did not have any significant difference in maternal and gestational age at the time of intervention, primary Bishop score, parity and neonatal weight. The number of deliveries in the first 24 hours was greater in the misoprostol group. Duration of onset of intervention to proper contractions was longer in the misoprostol group. However, the number of deliveries between 6-12 hours, 12-18 hours and 18-24 hours after induction was greater in the misoprostol group. The incidence of tachysystole and meconium was greater in the misoprostol group.Impact statementWhat is already known on this subject? Labour induction is widely used where the continuation of pregnancy might be dangerous for the mother or the baby. Of the various methods used for induction, misoprostol which is a prostaglandin E1 analogue has been reviewed more in recent years. Misoprostol has various routes of administration but in most studies only vaginal administration has been evaluated, leaving us with limited data about oral administration.What do the results of this study add? Oral misoprostol is a suitable method for labour induction and can be used as an alternative to oxytocin.What are the implications of these findings for clinical practice and/or further research? Misoprostol is not expensive, has a long shelf life, accessible in underdeveloped countries and rural areas and has several routes of administrations such as oral, sublingual and vaginal. Despite the fact that the oral route of misoprostol has a fast absorption and easier administration, there are relatively few studies assessing the the use of the oral route of misoprostol. Misoprostol is a suitable method for Labour induction and it has the potentials of being used as an alternative for oxytocin, however, the optimum dosages, the preferred route of administration, the maximum dose, the maximum time for administration, and maternal and neonatal safety should be studied more.

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.

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.