Induction of labor: the misoprostol controversy

Outcome of misoprostol and oxytocin in induction of labour

BACKGROUND

Induction of labour is the process of initiating the labour by artificial means from 24 weeks of gestation. The main aim of this study is to find out the maternal and foetal outcomes after induction of labour with misoprostol and oxytocin beyond 37 weeks of gestation.

METHODS

This was a hospital-based observational study carried out at Paropakar Maternity and Women's Hospital, Nepal. Misoprostol of 25 µg was inserted in posterior fornix of vagina or oxytocin infusion was started from 2.5 units on whom induction was decided. Maternal and foetal/neonatal outcomes were observed. Collected data were analysed using SPSS and MS Excel.

RESULTS

General induction rate was found to be 7.2%. In this study, post-term pregnancy was found to be the most common reason for induction of labour. Analysis of onset of labour led to the finding that mean onset of labour was much rapid in oxytocin (6.6 h) than misoprostol (13.6 h). However, there is similarity in induction-delivery interval in both groups. Overall, the rate of normal delivery and caesarean section was found to be 64.9% and 33.2%, respectively. Similarly, normal delivery within 12 h was seen in 18.4% of the patients given with misoprostol and 43.5% in oxytocin group. Foetal distress was found as the most common reason for caesarean section. The overall occurrence of maternal complication was found to be similar in misoprostol and oxytocin groups, nausea/vomiting being the most common (36.7%) complication followed by fever (24.1%). Besides this, the most common neonatal complication found in overall cases was meconium stained liquor (49.2%).

CONCLUSION

It was found that misoprostol was used most frequently for induction of labour compared to oxytocin. The onset of labour was found to be rapid in oxytocin than misoprostol. However, the occurrence of side effects was found to be similar in both misoprostol and oxytocin groups.

Orally administered misoprostol for induction of labor with prelabor rupture of membranes at term

Prelabor rupture of membranes (PROM) occurs in approximately 8% to 10% of women with term pregnancies. The management of PROM continues to be controversial. Approaches include expectant management and immediate induction of labor. The use of orally administered misoprostol for the management of women with PROM may provide significant advantages when they choose immediate induction of labor. This literature review presents current evidence that supports the use of oral misoprostol for women with PROM, including the benefits of a decreased interval time from PROM to vaginal birth, good safety profile, and reductions in the use of oxytocin augmentation and epidural anesthesia. In addition to clinically proven benefits to women of oral misoprostol for PROM, it also has the potential to reduce chorioamnionitis by reducing the number of sterile vaginal examinations performed thereby reducing the risk of ascending bacteria. Women have also reported acceptability and satisfaction when using oral misoprostol for immediate induction of labor. This review of literature discusses what is known about the use of orally administered misoprostol for the management of term PROM and makes recommendations for clinical use.

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.

Gastrointestinal prophylaxis in neurocritical care

The aim of this study is to review and summarize the relevant literature regarding pharmacologic and non-pharmacologic methods of prophylaxis against gastrointestinal (GI) stress ulceration, and upper gastrointestinal bleeding in critically ill patients. Stress ulcers are a known complication of a variety of critical illnesses. The literature regarding epidemiology and management of stress ulcers and complications thereof, is vast and mostly encompasses patients in medical and surgical intensive care units. This article aims to extrapolate meaningful data for use with a population of critically ill neurologic and neurosurgical patients in the neurological intensive care unit setting. Studies were identified from the Cochrane Central Register of controlled trials and NLM PubMed for English articles dealing with an adult population. We also scanned bibliographies of relevant studies. The results show that H(2)A, sucralfate, and PPI all reduce the incidence of UGIB in neurocritically ill patients, but H(2)A blockers may cause encephalopathy and interact with anticonvulsant drugs, and have been associated with higher rates of nosocomial pneumonias, but causation remains unproven and controversial. For these reasons, we advocate against routine use of H(2)A for GI prophylaxis in neurocritical patients. There is a paucity of high-level evidence studies that apply to the neurocritical care population. From this study, it is concluded that stress ulcer prophylaxis among critically ill neurologic and neurosurgical patients is important in preventing ulcer-related GI hemorrhage that contributes to both morbidity and mortality. Further, prospective trials are needed to elucidate which methods of prophylaxis are most appropriate and efficacious for specific illnesses in this population.

The Latent Phase of Labor: Diagnosis and Management

The latent phase of labor is complex and not completely understood by modern science. Studies often ignore evaluation of this phase of labor because determination of onset is subjective. In this article, the definition and time parameters of latent phase labor are discussed, and generalized distinctions between prelabor and labor are evaluated. Outpatient relief measures for latent phase as well as inpatient medical interventions for prolonged latent phase of labor are reviewed. Recommendations for policy development are included along with a discussion about the need to consider the significance of time limits. For optimal outcomes, clinicians are encouraged to individualize a management plan that is made in collaboration with the laboring woman.

Low-dose oral misoprostol for induction of labor: a systematic review

OBJECTIVE

To estimate the efficacy and safety of low-dose oral misoprostol compared with dinoprostone (PGE2), vaginal misoprostol, and oxytocin for labor induction in women with a viable fetus.

DATA SOURCES

We conducted electronic database searches of PubMed, MEDLINE, EMBASE, and the Cochrane Library for articles published before January 2008 using the keywords misoprostol, labor, induction, randomized controlled trials, dinoprostone, oxytocin, pregnancy, and maternal and fetal side effects.

METHODS OF STUDY SELECTION

We included randomized controlled trials comparing 20-25 micrograms oral misoprostol with vaginal misoprostol, dinoprostone or oxytocin given to women at 32-42 weeks of gestation for labor induction. From 401 citations identified, results from nine studies were finally analyzed using the Review Manager software. Relative risk (RR) and 95% confidence intervals (CIs) were calculated using fixed and random-effects models.

TABULATION, INTEGRATION, AND RESULTS

Nine articles with 2,937 women met the inclusion criteria. The five trials comparing oral misoprostol and dinoprostone showed significantly fewer women requiring cesarean delivery in the misoprostol group (20% compared with 26%; RR 0.82, 95% CI 0.71-0.96). There were no statistically significant differences in risks of uterine hyperstimulation or need for oxytocin augmentation. Two trials compared oral with vaginal low-dose misoprostol. Women using oral misoprostol were significantly less likely to experience uterine hyperstimulation with fetal heart rate changes (2% compared with 13%; RR 0.19, 95% CI 0.08-0.46), but there were no significant differences in other outcomes.

CONCLUSION

Low-dose oral misoprostol solution (20 micrograms) administered every 2 hours seems at least as effective as both vaginal dinoprostone and vaginal misoprostol, with lower rates of cesarean delivery and uterine hyperstimulation, respectively.

Sublingual compared with vaginal misoprostol for labour induction at term: a randomised controlled trial

OBJECTIVE

To compare the efficacy and safety of 50 microg of sublingual misoprostol with 25 microg of vaginal misoprostol administered for labour induction at term. Design Double-blinded, randomised controlled trial. Setting University Hospital, Kaunas, Lithuania. Sample A total of 140 women at term with indications for labour induction. Methods Women were randomised to receive either 50 microg of sublingual misoprostol with vaginal placebo (n = 70) or sublingual placebo with 25 microg of vaginal misoprostol (n = 70) every 4 hours (maximum six doses). Main outcome measures The number of women delivering vaginally within 24 hours of labour induction. Results Fifty-eight women (83%) in the sublingual misoprostol group and 53 (76%) in the vaginal misoprostol group delivered vaginally within 24 hours [relative risk (RR) 1.1, 95% confidential interval (CI) 0.9-1.3]. However, the induction to vaginal delivery time was significantly shorter in the sublingual group (15.0 +/- 3.7 hours) compared with the vaginal group (16.7 +/- 4.1 hours, P = 0.03). The incidence of tachysystole was more than three-fold higher in the sublingual than in the vaginal group (14 versus 4.3%; RR 3.3, 95% CI 0.9-11.6), but this was not statistically significant. There were no significant differences in the incidence of hypertonus or hyperstimulation syndrome, mode of delivery, interventions for fetal distress or neonatal outcomes between the two groups. Conclusion A 50 microg of sublingual misoprostol 4 hourly for labour induction at term seems to have similar efficacy as 25 microg of vaginal misoprostol. Further studies on safety with larger numbers of women need to be conducted before routine sublingual misoprostol use in this setting.

Clinical Use of Relaxin to Facilitate Birth: Reasons for Investigating the Premise

In the United States, both medical and nonmedical factors have driven the cesarean section rate to over 26% of all deliveries. In addition to questions of increased cost associated with operative delivery, some have questioned the ethics of performing cesarean section for nonmedical reasons. Reduction of both the duration and the pain associated with vaginal delivery would likely bring about a decline in the rate of both medical and nonmedical cesarean sections. This chapter summarizes recent findings that support the premise that through its growth-promoting and softening effects on the cervix, short-term subcutaneous administration of pharmacologic amounts of relaxin to women at term holds promise as a means of reducing the duration and discomfort associated with delivery. Two recent studies conducted in pregnant rats demonstrated that the cervix is highly responsive to relaxin during the antepartum period and that short-term subcutaneous administration of the hormone to relaxin-deficient animals not only promotes growth and softening of the cervix, but also reduces the duration of labor and delivery. Moreover, recent human clinical trials examining the influence of 24 weeks of continuous subcutaneous administration of recombinant human relaxin for the treatment of scleroderma provided evidence not only that the human reproductive tract is responsive to relaxin, but also that the administration of the hormone does not cause serious adverse side effects. It is concluded that recent findings provide an impetus for an investigation into relaxin's potential for cervical remodeling and facilitating birth in women.

Misoprostol use for labor induction in developing countries: a prospective study in Guinea

BACKGROUND

The purpose of this study was to assess the efficacy, side effects and cost of misoprostol regimens in various obstetrical situations frequently occurring in developing countries.

STUDY DESIGN

One hundred and four parturient women with indications for labor induction received different regimens of misoprostol in the range of 50-800 microg according to their gestational age. Misoprostol was administered by the vaginal route, every 6h without exceeding four doses.

RESULTS

All indications for labor induction concerned women with a gestational age of more than 30 weeks, except in the intrauterine death cases. The mean overall duration of labor was 7.8 h (+/-4.6 h). The mean amount of misoprostol used was 226 microg (+/-196 microg). The difference in the mean labor duration between the four indications for induction was statistically significant (P<0.01). It was also significant for the mean total dose of misoprostol used. Total dose of misoprostol and Bishop score were inversely proportional. Two caesarean deliveries and two uterine ruptures were recorded, but no maternal deaths. The mean Apgar score was 8.0 (+/-1) at 1 min and 9.5 (+/-0.8) at 5 min. In our series, four fetal deaths occurred. The mean cost of misoprostol for labor induction was around US$ 1, with a range of 0.05-4.

CONCLUSIONS

The use of vaginal misoprostol appears to be relevant in developing countries in cases where labor induction is indicated. Nevertheless, the advantages of misoprostol (low cost, facility of storage) are counter-balanced by side-effects (C-section, uterine rupture) which can be harmful for the mother and also for the newborn.

Reducing postpartum hemorrhage in Africa

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality in sub-Saharan Africa. This is being addressed by leading professional organizations, which point to the importance of a skilled attendant at birth. But they also emphasize that the active management of the third stage of labor is proven to reduce the incidence of PPH. In low-income settings, the prostaglandin misoprostol should be considered as it is low-cost, stable at room temperature and easy to administer.