Neste documento vou colocar por ordem cronológica as últimas revisões sistemáticas.
West HM, Jozwiak M, Dodd JM. Methods of term labour induction for women with a previous caesarean section. Cochrane Database of Systematic Reviews 2017, Issue 6. Art. No.: CD009792. DOI: 10.1002/14651858.CD009792.pub3.
[…]Vaginal misoprostol versus intravenous oxytocin (one trial, 38 women): this trial stopped early because one woman who received misoprostol had a uterine rupture (RR 3.67, 95% CI 0.16 to 84.66) and one had uterine dehiscence. No other outcomes (including GRADE outcomes) were reported. […] Implications for practice
There is insufficient information available from randomised controlled trials to inform clinical decisions regarding the optimal method of induction of labour in women with a prior caesarean birth. For women with an unfavourable cervix who require induction of labour, the risks and benefits of mechanical and pharmacologic options of cervical ripening, as well as labour induction and augmentation need to be considered. Whilst the data in this review are insufficient to inform practice in terms of the best method of induction for women with a prior caesarean, it is important to highlight that one study, which used misoprostol, was stopped early due to serious complications associated with its use.[…]
Weeks AD, Navaratnam K, Alfirevic Z. Simplifying oral misoprostol protocols for the induction of labour. BJOG. 2017;124(11):1642-1645.
[…]‘Oral misoprostol’, however, is not a single entity and systematic reviewers have struggled to cope with the wide variation in protocols (Table 1). Published randomised trials have a wide variety of misoprostol doses (20–200 μg) and frequency of administration (1–6 hourly). Some protocols use a single dose for the whole induction period, whereas others escalate the dose until the desired effect is achieved. Some use misoprostol purely for cervical ripening and replace it with an oxytocin infusion once membrane rupture is feasible, whereas others use oral misoprostol continuously until delivery. But the variation doesn’t stop there. Until recently there was no commercially produced low‐dose misoprostol tablet, and so clinicians developed their own ways of preparing and administering the intended dose. Some practitioners divided the small and notoriously crumbly 200‐ or 100‐μg tablets into fragments. Others made up 1‐μg/ml solutions by dissolving tablets in tap water. It is only recently that commercially available 25‐μg tablets have become available (Cipla, India; Azanta A/S, Denmark), but these are not yet widely available. […]What is the way forward? Although off‐label drug use remains essential in pregnancy (for example with betamethasone for fetal lung maturation), clinicians continue to worry about using an off‐label drug when labelled alternatives are available. The development or import of a commercially available 25‐μg tablet licensed for labour induction would therefore be a major advance and would provide a definitive protocol. Until that time we recommend the use of 25‐μg tablets or solution used every 2 hours. It appears to be safe to use it up to the time of birth rather than simply for cervical ripening; however, use of this ‘extended’ protocol should include close observation and the use of acute tocolytics when hyperstimulation is suspected. There are no direct comparisons of the extended protocol with the standard regimen, nor of the stepped increase in misoprostol dose up to 50 μg. However, they appear to be safe and effective in studies in which they have been used. More research is required into ways of reducing adverse outcomes in high‐risk groups (nulliparous women or those with a scarred uterus), potentially using a combination of mechanical and uterotonic methods.[…]
Alfirevic Z, Keeney E, Dowswell T, et al. Methods to induce labour: a systematic review, network meta-analysis and cost-effectiveness analysis. BJOG. 2016;123(9):1462-70.
Future trials should be designed and powered to detect a method that is more cost-effective than low-dose titrated oral misoprostol.
Chen W, Xue J, Peprah MK, Wen SW, Walker M, Gao Y, Tang Y. A systematic review and network meta‐analysis comparing the use of Foley catheters, misoprostol, and dinoprostone for cervical ripening in the induction of labour. BJOG 2016;123:346–354.
No method of labour induction demonstrated overall superiority when considering all three clinical outcomes. Decisions regarding the choice of induction method will depend upon the relative preference for effecting vaginal delivery within 24 hours, minimising the incidence of uterine hyperstimulation with adverse FHR changes and avoiding caesarean section. (abstract)
Vaginal misoprostol followed by vaginal dinoprostone are the most effective methods for induction of labour after 28 weeks of gestation in women with intact membranes, in terms of achieving delivery within 24 hours; however, these methods are associated with higher rates of uterine hyperstimulation with adverse FHR changes. In contrast, mechanical induction using Foley catheters was the least effective method of induction, along with oral misoprostol and intracervical dinoprostone, but had the lowest incidence of uterine hyperstimulation with FHR changes. Oral misoprostol was the best method of induction in terms of reducing the likelihood of delivery by caesarean section, and caused less uterine hyperstimulation with FHR changes than vaginal misoprostol.
Alfirevic Z, Keeney E, Dowswell T, et al. Labour induction with prostaglandins: a systematic review and network meta-analysis. BMJ. 2015;350:h217. Published 2015 Feb 5. doi:10.1136/bmj.h217
Low dose(<50 µg) titrated oral misoprostol solution had the lowest probability of caesarean section, whereas vaginal misoprostol (≥50 µg) had the highest probability of achieving a vaginal delivery within 24 hours. These findings have important implications for a series of current national and international guidelines for induction of labour and future research in this area.
Alfirevic Z, Aflaifel N, Weeks A. Oral misoprostol for induction of labour. Cochrane Database of Systematic Reviews 2014, Issue 6. Art. No.: CD001338. DOI: 10.1002/14651858.CD001338.pub3
Oral misoprostol as an induction agent is effective at achieving vaginal birth. It is more effective than placebo, as effective as vaginal misoprostol and vaginal dinoprostone, and results in fewer caesarean sections than oxytocin alone.
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.
A systematic review and meta-analysis admin 2019-05-24T08:23:05+00:00
Intravaginal misoprostol appears to be more efficient for labor induction than intracervical dinoprostone; however, dinoprostone has been demonstrated to be safer because of the lower incidence of uterine hyperstimulation and tachysystole. Further high-quality studies assessing the possible effectiveness of misoprostol and dinoprostone in selected groups of patients are warranted.
Hofmeyr GJ, Gülmezoglu AM, Pileggi C. Vaginal misoprostol for cervical ripening and induction of labour. Cochrane Database of Systematic Reviews 2010, Issue 10. Art. No.: CD000941. DOI: 10.1002/14651858.CD000941.pub2.
Vaginal misoprostol is effective in inducing labour but more research is needed on safety
Sometimes it is necessary to bring on labour artificially because of safety concerns for the mother or baby. Misoprostol is a hormone given by insertion through the vagina or rectum, or by mouth to ripen the cervix and bring on labour. The review of 121 trials found that larger doses of misoprostol are more effective than prostaglandin and that oxytocin is used in addition less often. However, misoprostol also increases hyperstimulation of the uterus. With smaller doses, the results are similar to other methods. The trials reviewed are too small to determine whether the risk of rupture of the uterus is increased. More research is needed into the safety and best dosages of misoprostol. Another Cochrane review has shown that the oral route of administration is preferable to the vaginal route.