Relaxin for cervical ripening and induction of labour

Identification and Quantification of Human Relaxin Proteins by Immunoaffinity-Mass Spectrometry

The human relaxins belong to the Insulin/IGF/Relaxin superfamily of peptide hormones, and their physiological function is primarily associated with reproduction. In this study, we focused on a prostate tissue-specific relaxin RLN1 (REL1_HUMAN protein) and a broader tissue specificity RLN2 (REL2_HUMAN protein). Due to their structural similarity, REL1 and REL2 proteins were collectively named a 'human relaxin protein' in previous studies and were exclusively measured by immunoassays. We hypothesized that the highly selective and sensitive immunoaffinity-selected reaction monitoring (IA-SRM) assays would reveal the identity and abundance of the endogenous REL1 and REL2 in biological samples and facilitate the evaluation of these proteins for diagnostic applications. High levels of RLN1 and RLN2 transcripts were found in prostate and breast cancer cell lines by RT-PCR. However, no endogenous prorelaxin-1 or mature REL1 were detected by IA-SRM in cell lines, seminal plasma, or blood serum. The IA-SRM assay of REL2 demonstrated its undetectable levels (<9.4 pg/mL) in healthy control female and male sera and relatively high levels of REL2 in maternal sera across different gestational weeks (median 331 pg/mL; N = 120). IA-SRM assays uncovered potential cross-reactivity and nonspecific binding for relaxin immunoassays. The developed IA-SRM assays will facilitate the investigation of the physiological and pathological roles of REL1 and REL2 proteins.

Signaling Pathways Regulating Human Cervical Ripening in Preterm and Term Delivery

At the end of gestation, the cervical tissue changes profoundly. As a result of these changes, the uterine cervix becomes soft and vulnerable to dilation. The process occurring in the cervical tissue can be described as cervical ripening. The ripening is a process derivative of enzymatic breakdown and inflammatory response. Therefore, it is apparent that cervical remodeling is a derivative of the reactions mediated by multiple factors such as hormones, prostaglandins, nitric oxide, and inflammatory cytokines. However, despite the research carried out over the years, the cellular pathways responsible for regulating this process are still poorly understood. A comprehensive understanding of the entire process of cervical ripening seems crucial in the context of labor induction. Greater knowledge could provide us with the means to help women who suffer from dysfunctional labor. The overall objective of this review is to present the current understanding of cervical ripening in terms of molecular regulation and cell signaling.

Human Recombinant Relaxin (Serelaxin) as Anti-fibrotic Agent: Pharmacology, Limitations and Actual Perspectives

Relaxin (recombinant human relaxin-2 hormone; RLX-2; serelaxin) had raised expectations as a new medication for fibrotic diseases. A plethora of in vitro and in vivo studies have offered convincing demonstrations that relaxin promotes remodelling of connective tissue extracellular matrix mediated by inhibition of multiple fibrogenic pathways, especially the downstream signalling of transforming growth factor (TGF)-β1, a major pro-fibrotic cytokine, and the recruitment and activation of myofibroblast, the main fibrosis-generating cells. However, all clinical trials with relaxin in patients with fibrotic diseases gave inconclusive results. In this review, we have summarized the molecular mechanisms of fibrosis, highlighting those which can be effectively targeted by relaxin. Then, we have performed a critical reappraisal of the clinical trials performed to-date with relaxin as anti-fibrotic drug, in order to highlight their key points of strength and weakness and to identify some future opportunities for the therapeutic use of relaxin, or its analogues, in fibrotic diseases and pathologic scarring which, in our opinion, deserve to be investigated.

A comparison between induction of labor with 3 methods of titrated oral misoprostol, constant dose of oral misoprostol and Foley catheter with extra amniotic saline infusion (EASI), in women with unfavorable cervix

Background: Different methods of cervical ripening and induction of labor have been used in the cases of unfavorable cervix with different levels of success, but no method has been found to be the best option. The purpose of the present study was to find the effects and side effects of three different methods of cervical ripening and induction of labor. These three methods were oral titrated misoprostol, constant dose of oral misoprostol and Foley catheter with extra-amniotic saline infusion.

Methods: This clinical trial was performed on women with unfavorable cervix who had been admitted in Akbarabadi Teaching Hospital for induction of labor and had bishop score of less than six; between March 2014- March 2015. The eligible women were assigned into three groups. In titrated oral misoprostol group (n=33), titrated solution of misoprostol, and in oral misoprostol group (n=33), 50µg oral misoprostol every four hours and in Foley catheter group (n=50), Foley catheter with extra-amniotic saline infusion were administered. The main outcome was the number of vaginal deliveries during the first 24 hours. In addition, number of cesarean deliveries and adverse effects were compared between the three groups. The obtained data were analyzed using SPSS 18 software. Data analysis was performed according to the intention to treat principle. Chi-square test, Fisher Exact test, Student ttest, and Mann-Whitney U test, were used for comparing data. P-value≤0.05 was considered statistically significant.

Results: The three groups did not have any significant difference according to maternal age, gestational age at the time of admission, gravidity, parity, and primary Bishop Score. There was no significant difference between the three groups for the main outcome, which was vaginal delivery during the first 24 hours (p=0.887). There was no significant difference between the three groups according to hypertonicity, uterine hyperstimulation, meconium passage, non-reassuring fetal heart rate, neonatal Apgar score in minutes one and 5, and mean duration of beginning the intervention up to delivery. However, uterine tachysystole and NICU admission were more in the group to whom the titrated solution of misoprostol was administered (p=0.002 and p=0.037 respectively). The number of cesarean deliveries due to failure to progress was higher in the EASI group. However, EASI group showed the least number of none-reassuring fetal heart rate between the three groups. Meconium passage was more in the titrated misoprostol group, but the difference was not significant.

Conclusion: All three methods are appropriate methods for induction of labor in the cases of unfavorable cervix; and choosing each method depends on the expertise of labor staff, accessibility to the medications, cost, and taking care for monitoring the patients and adverse effects.

Relaxin 2/RXFP1 Signaling Induces Cell Invasion via the β-Catenin Pathway in Endometrial Cancer

Relaxin is known to play an important role in animal pregnancies, including those of humans. It is suggested that relaxin induces aggressive cell growth and invasiveness in several types of cancer, including endometrial cancer. However, the mechanisms of relaxin remain largely unclear. In this study, we examined the effects of relaxin 2 (RLN2), the major circulating relaxin in humans, on human endometrial carcinoma cell lines. RLN2 treatment induced invasion in HEC-1B and Ishikawa cells. RLN2-induced cell invasion was significantly decreased by transfection of relaxin receptor 1 (RXFP1) siRNAs. The β-catenin inhibitor, XAV939, also significantly inhibited the RLN2-induced cell invasions. Both a decrease of cadherin expression and an increase of β-catenin phosphorylation were observed in response to the RLN2 treatment in HEC-1B and Ishikawa cells. We then examined RLN2 and RXFP1 expression in 80 human endometrioid endometrial carcinoma tissues. RLN2 immunoreactivity was detected in the human endometrial carcinoma cells and had a correlative tendency with histological grade and RXFP1. These results suggest that adherens junctions in cancer cells are weakened by the breakdown of the cadherin/catenin complex, which is induced by β-catenin phosphorylation via RLN2/RXFP1 signaling.

Acupuncture or acupressure for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction. The use of complementary therapies is increasing. Women may look to complementary therapies during pregnancy and childbirth to be used alongside conventional medical practice. Acupuncture involves the insertion of very fine needles into specific points of the body. Acupressure is using the thumbs or fingers to apply pressure to specific points. The limited observational studies to date suggest acupuncture for induction of labour has no known adverse effects to the fetus, and may be effective. However, the evidence regarding the clinical effectiveness of this technique is limited.

OBJECTIVES

To determine, from the best available evidence, the effectiveness and safety of acupuncture and acupressure for third trimester cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2016), PubMed (1966 to 25 November 2016), ProQuest Dissertations & Theses (25 November 2016), CINAHL (25 November 2016), Embase (25 November 2016), the WHO International Clinical Trials Registry Portal (ICTRP) (3 October 2016), and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials comparing acupuncture or acupressure, used for third trimester cervical ripening or labour induction, with placebo/no treatment or other methods on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

This updated review includes 22 trials, reporting on 3456 women. The trials using manual or electro-acupuncture were compared with usual care (eight trials, 760 women), sweeping of membranes (one trial, 207 women), or sham controls (seven trials, 729 women). Trials using acupressure were compared with usual care (two trials, 151 women) or sham controls (two trials, 239 women). Many studies had a moderate risk of bias.Overall, few trials reported on primary outcomes. No trial reported vaginal delivery not achieved within 24 hours and uterine hyperstimulation with fetal heart rate (FHR) changes. Serious maternal and neonatal death or morbidity were only reported under acupuncture versus sham control. Acupuncture versus sham control There was no clear difference in caesarean sections between groups (average risk ratio (RR) 0.80, 95% confidence interval (CI) 0.56 to 1.15, eight trials, 789 women; high-quality evidence). There were no reports of maternal death or perinatal death in the one trial that reported this outcome. There was evidence of a benefit from acupuncture in improving cervical readiness for labour (mean difference (MD) 0.40, 95% CI 0.11 to 0.69, one trial, 125 women), as measured by cervical maturity within 24 hours using Bishop's score. There was no evidence of a difference between groups for oxytocin augmentation, epidural analgesia, instrumental vaginal birth, meconium-stained liquor, Apgar score < 7 at five minutes, neonatal intensive care admission, maternal infection, postpartum bleeding greater than 500 mL, time from the trial to time of birth, use of induction methods, length of labour, and spontaneous vaginal birth. Acupuncture versus usual care There was no clear difference in caesarean sections between groups (average RR 0.77, 95% CI 0.51 to 1.17, eight trials, 760 women; low-quality evidence). There was an increase in cervical maturation for the acupuncture (electro) group compared with control (MD 1.30, 95% CI 0.11 to 2.49, one trial, 67 women) and a shorter length of labour (minutes) in the usual care group compared to electro-acupuncture (MD 124.00, 95% CI 37.39 to 210.61, one trial, 67 women).There appeared be a differential effect according to type of acupuncture based on subgroup analysis. Electro-acupuncture appeared to have more of an effect than manual acupuncture for the outcomes caesarean section (CS), and instrumental vaginal and spontaneous vaginal birth. It decreased the rate of CS (average RR 0.54, 95% CI 0.37 to 0.80, 3 trials, 327 women), increased the rate of instrumental vaginal birth (average RR 2.30, 95%CI 1.15 to 4.60, two trials, 271 women), and increased the rate of spontaneous vaginal birth (average RR 2.06, 95% CI 1.20 to 3.56, one trial, 72 women). However, subgroup analyses are observational in nature and so results should be interpreted with caution.There were no clear differences between groups for other outcomes: oxytocin augmentation, use of epidural analgesia, Apgar score < 7 at 5 minutes, neonatal intensive care admission, maternal infection, perineal tear, fetal infection, maternal satisfaction, use of other induction methods, and postpartum bleeding greater than 500 mL. Acupuncture versus sweeping if fetal membranes One trial of acupuncture versus sweeping of fetal membranes showed no clear differences between groups in caesarean sections (RR 0.64, 95% CI 0.34 to 1.22, one trial, 207 women, moderate-quality evidence), need for augmentation, epidural analgesia, instrumental vaginal birth, Apgar score < 7 at 5 minutes, neonatal intensive care admission, and postpartum bleeding greater than 500 mL. Acupressure versus sham control There was no evidence of benefit from acupressure in reducing caesarean sections compared to control (RR, 0.94, 95% CI 0.68 to 1.30, two trials, 239 women, moderate-quality evidence). There was no evidence of a clear benefit in reduced oxytocin augmentation, instrumental vaginal birth, meconium-stained liquor, time from trial intervention to birth of the baby, and spontaneous vaginal birth. Acupressure versus usual care There was no evidence of benefit from acupressure in reducing caesarean sections compared to usual care (RR 1.02, 95% CI 0.68 to 1.53, two trials, 151 women, moderate-quality evidence). There was no evidence of a clear benefit in reduced epidural analgesia, Apgar score < 7 at 5 minutes, admission to neonatal intensive care, time from trial intervention to birth of the baby, use of other induction methods, and spontaneous vaginal birth.

AUTHORS' CONCLUSIONS

Overall, there was no clear benefit from acupuncture or acupressure in reducing caesarean section rate. The quality of the evidence varied between low to high. Few trials reported on neonatal morbidity or maternal mortality outcomes. Acupuncture showed some benefit in improving cervical maturity, however, more well-designed trials are needed. Future trials could include clinically relevant safety outcomes.

Synthetic non-peptide low molecular weight agonists of the relaxin receptor 1

Relaxin is a small heterodimeric peptide hormone of the insulin/relaxin superfamily produced mainly in female and male reproductive organs. It has potent antifibrotic, vasodilatory and angiogenic effects and regulates the normal function of various physiological systems. Preclinical studies and recent clinical trials have shown the promise of recombinant relaxin as a therapeutic agent in the treatment of cardiovascular and fibrotic diseases. However, there are the universal drawbacks of peptide-based pharmacology that apply to relaxin: a short half-life in vivo requires its continuous delivery, and there are high costs of production, storage and treatment, as well as the possibility of immune responses. All these issues can be resolved by the development of low non-peptide MW agonists of the relaxin receptors which are stable, bioavailable, easily synthesized and specific. In this review, we describe the discovery and characterization of the first series of such compounds. The lead compound, ML290, binds to an allosteric site of the relaxin GPCR, RXFP1. ML290 shows high activity and efficacy, measured by cAMP response, in cells expressing endogenous or transfected RXFP1. Relaxin-like effects of ML290 were shown in various functional cellular assays in vitro. ML290 has excellent absorption, distribution, metabolism and excretion properties and in vivo stability. The identified series of low MW agonists does not activate rodent RXFP1 receptors and thus, the production of a RXFP1 humanized mouse model is needed for preclinical studies. The future analysis and clinical perspectives of relaxin receptor agonists are discussed.

LINKED ARTICLES

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.

Nitric oxide donors for cervical ripening and induction of labour

BACKGROUND

Sometimes it is necessary to bring on labour artificially because of safety concerns for the mother or baby. This review is one of a series of reviews of methods of labour induction using a standardised protocol.

OBJECTIVES

To determine the effects of NO donors (isosorbide mononitrate (ISMN), isosorbide dinitrate (ISDN), nitroglycerin and sodium nitroprusside) for third trimester cervical ripening or induction of labour, in comparison with placebo or no treatment or other treatments from a predefined hierarchy.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (15 August 2016) and the reference lists of trial reports.

SELECTION CRITERIA

Clinical trials comparing NO donors for cervical ripening or labour induction with other methods listed above it on a predefined list of methods of labour induction. Interventions include NO donors (isosorbide mononitrate, isosorbide dinitrate, nitroglycerin and sodium nitroprusside) compared with other methods listed above it on a predefined list of methods of labour induction.

DATA COLLECTION AND ANALYSIS

This review is part of a series of reviews focusing on methods of induction of labour, based on a generic protocol. Three review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. In this update, the quality of the evidence for the main comparison was assessed using the GRADE approach.

MAIN RESULTS

We included 23 trials (including a total of 4777 women). Included studies compared NO donors with placebo, vaginal prostaglandin E2 (PGE2), intracervical PGE2, vaginal misoprostol and intracervical Foley catheter. The majority of the included studies were assessed as being at low risk of bias. Nitric oxide versus placebo There was no evidence of a difference for any of the primary outcomes analysed: vaginal delivery not achieved in 24 hours (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.83 to 1.15; one trial, 238 women; low-quality evidence), uterine hyperstimulation with fetal heart rate (FHR) changes (RR 0.09, 95% CI 0.01 to 1.62; two trials, 300 women; low-quality evidence), caesarean section (RR 0.99, 95% CI 0.88 to 1.11; nine trials, 2624 women; moderate-quality evidence) or serious neonatal morbidity/perinatal death (average RR 1.61, 95% CI 0.08 to 33.26; two trials, 1712 women; low-quality evidence). There were no instances of serious maternal morbidity or death (one study reported this outcome).There was a reduction in an unfavourable cervix at 12 to 24 hours in women treated with NO donors (average RR 0.78, 95% CI 0.67 to 0.90; four trials, 762 women), and this difference was observed in both subgroups of standard release and slow release formulation. Women who received NO donors were less likely to experience uterine hyperstimulation without FHR rate changes (RR 0.05, 95% CI 0.00 to 0.80; one trial, 200 women), and more likely to experience side effects, including nausea, headache and vomiting. Nitric oxide donors versus vaginal prostaglandins There was no evidence of any difference between groups for uterine hyperstimulation with FHR changes or caesarean section (RR 0.97, 95% CI 0.78 to 1.21; three trials, 571 women). Serious neonatal morbidity and serious maternal morbidity were not reported. There were fewer women in the NO donor group who did not achieve a vaginal delivery within 24 hours (RR 0.63, 95% CI 0.47 to 0.86; one trial, 400 primiparae women). Nitric oxide donors versus intracervical prostaglandins One study reported a reduction in the number of women who had not achieved a vaginal delivery within 24 hours with NO donors (RR 0.63, 95% CI 0.47 to 0.86; one trial, 400 women). This result should be interpreted with caution as the information was extracted from an abstract only and a full report of the study is awaited. No differences were observed between groups for uterine hyperstimulation with FHR changes (RR 0.33, 95% CI 0.01 to 7.74; one trial, 42 women) or serious neonatal morbidity/perinatal death (RR 0.33, 95% CI 0.01 to 7.74; one trial, 42 women). Fewer women in the NO donor group underwent a caesarean section in comparison to women who received intracervical prostaglandins (RR 0.63, 95% CI 0.44 to 0.90; two trials, 442 women). No study reported on the outcome serious maternal morbidity or death. Nitric oxide donors versus vaginal misoprostol There was a reduction in the rate of uterine hyperstimulation with FHR changes with NO donors (RR 0.07, 95% CI 0.01 to 0.37; three trials, 281 women). There were no differences in caesarean section rates (RR 1.00, 95% CI 0.82 to 1.21; 761 women; six trials) and no cases of serious neonatal morbidity/perinatal death were reported. One study found that women in the NO donor group were more likely to not deliver within 24 hours (RR 5.33, 95% CI 1.62 to 17.55; one trial, 150 women). Serious maternal morbidity or death was not reported.In terms of secondary outcomes, there was an increase in cervix unchanged/unfavourable with NO (RR 3.43, 95% CI 2.07 to 5.66; two trials, 151 women) and an increase in the need for oxytocin augmentation with NO induction (RR 2.67, 95% CI 1.31 to 5.45; 7 trials; 767 women), although there was evidence of significant heterogeneity which could not be fully explained. Uterine hyperstimulation without FHR was lower in the NO group, as was meconium-stained liquor, Apgar score less than seven at five minutes and analgesia requirements. Nitric oxide donors versus intracervical catheter There was no evidence on any difference between the effects of NO and the use of a Foley catheter for induction of labour for caesarean section (RR 1.00, 95% CI 0.39 to 2.59; one trial, 80 women). No other primary outcomes were reported. One study of 75 participants did not contribute any data to the review.For all comparisons, women who received NO donors were more likely to experience side effects such as headache, nausea or vomiting.

AUTHORS' CONCLUSIONS

Available data suggests that NO donors can be a useful tool in the process of induction of labour causing the cervix to be more favourable in comparison to placebo. However, additional data are needed to assess the true impact of NO donors on all important labour process and delivery outcomes.

Recombinant human relaxin versus placebo for cervical ripening: a double-blind randomised trial in pregnant women scheduled for induction of labour

BACKGROUND

Nonclinical studies indicate that the hormone relaxin is a good candidate for a safe cervical ripening agent that does not cause uterine contractions.

METHODS

This Phase II study (conducted November 2, 2005-October 20, 2006) was a randomised, double blind, placebo controlled trial testing 24-h intravenous infusion of serelaxin (recombinant human relaxin) or placebo for cervical ripening in 72 healthy, primiparous women. Eligible subjects had a singleton pregnancy ≥40 weeks, were planned for elective induction, had vertex presentation of the fetus, intact membranes and a Bishop score at screening ≤4. In Part A of the study, safety evaluation of three escalating doses of serelaxin (7.5, 25 or 75 μg/kg/day) or placebo was performed in 22 subjects admitted to the hospital 24 h prior to scheduled induction (n = 7, 4, 4, and 7 subjects, respectively). The highest safe dose from Part A and placebo were then tested in Part B for safety and cervical ripening (n = 25 subjects/arm). Planned randomisation ratio was of 4:2 (serelaxin:placebo) for each dose group in Part A and 1:1 for Part B. For analysis, subjects in Part B were pooled with those receiving the same dose in Part A and all subjects receiving placebo were pooled. The primary efficacy endpoint was change from baseline in Bishop score at 6, 12 and 24 h or end of study drug administration. Maternal safety evaluations included adverse events and vital signs through 4 weeks. Fetal assessments included serial heart rate monitoring and nonstress testing. Neonatal assessments included Apgar scores, NICU admissions, and adverse events through 4 weeks.

RESULTS

Overall, 74 subjects were randomized and 72 were treated. There were no significant differences between the groups receiving the highest safe dose of serelaxin (75 μg/kg/day) and placebo in the primary or secondary efficacy endpoints. Changes from baseline in Bishop score at 24 h were 4.19 ± 1.9 and 3.26 ± 2.26 in the pooled placebo and serelaxin groups, respectively (p = 0.2507). Serelaxin was well tolerated and no anti-serelaxin antibodies were detected in either subjects or neonates.

CONCLUSION

Serelaxin infusion at the end of pregnancy was well tolerated but did not advance cervical ripening.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT00259103 (15 November 2005).

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. This is one of a series of reviews evaluating methods of induction of labour. This review focuses on prostaglandins given per vaginam, evaluating these in comparison with placebo (or expectant management) and with each other; prostaglandins (PGE2 and PGF2a); different formulations (gels, tablets, pessaries) and doses.

OBJECTIVES

To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 March 2014) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing vaginal prostaglandins used for third trimester cervical ripening or labour induction with placebo/no treatment, with each other, or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

We assessed studies and extracted data independently.

MAIN RESULTS

Seventy randomised controlled trials (RCTs) (11,487 women) are included. In this update seven new RCTs (778 women) have been added. Two of these new trials compare PGE2 with no treatment, four compare different PGE2 formulations (gels versus tablets, or sustained release pessaries) and one trial compares PGF2a with placebo. The majority of trials were at unclear risk of bias for most domains.Overall, vaginal prostaglandin E2 compared with placebo or no treatment probably reduces the likelihood of vaginal delivery not being achieved within 24 hours. The risk of uterine hyperstimulation with fetal heart rate changes is increased (4.8% versus 1.0%, risk ratio (RR) 3.16, 95% confidence interval (CI) 1.67 to 5.98, 15 trials, 1359 women). The caesarean section rate is probably reduced by about 10% (13.5% versus 14.8%, RR 0.91, 95% CI 0.81 to 1.02, 36 trials, 6599 women). The overall effect on improving maternal and fetal outcomes (across a variety of measures) is uncertain.PGE2 tablets, gels and pessaries (including sustained release preparations) appear to be as effective as each other, small differences are detected between some outcomes, but these maybe due to chance.

AUTHORS' CONCLUSIONS

Prostaglandins PGE2 probably increase the chance of vaginal delivery in 24 hours, they increase uterine hyperstimulation with fetal heart changes but do not effect or may reduce caesarean section rates. They increase the likelihood of cervical change, with no increase in operative delivery rates. PGE2 tablets, gels and pessaries appear to be as effective as each other, any differences between formulations are marginal but may be important.

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.

Castor oil, bath and/or enema for cervical priming and induction of labour

BACKGROUND

Castor oil, a potent cathartic, is derived from the bean of the castor plant. Anecdotal reports, which date back to ancient Egypt have suggested the use of castor oil to stimulate labour. Castor oil has been widely used as a traditional method of initiating labour in midwifery practice. Its role in the initiation of labour is poorly understood and data examining its efficacy within a clinical trial are limited. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of castor oil or enemas for third trimester cervical ripening or induction of labour in comparison with other methods of cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing castor oil, bath or enemas used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

MAIN RESULTS

Three trials, involving 233 women, are included. There was no evidence of differences in caesarean section rates between the two interventions in the two trials reporting this outcome (risk ratio (RR) 2.04, 95% confidence interval (CI) 0.92 to 4.55). There were no data presented on neonatal or maternal mortality or morbidity.There was no evidence of a difference between castor oil and placebo/no treatment for the rate of instrumental delivery, meconium-stained liquor, or Apgar score less than seven at five minutes. The number of participants was too small to detect all but large differences in outcome. All women who ingested castor oil felt nauseous (RR 59.92, 95% CI 8.46 to 424.52).

AUTHORS' CONCLUSIONS

The three trials included in the review contain small numbers of women. All three studies used single doses of castor oil. The results from these studies should be interpreted with caution due to the risk of bias introduced due to poor methodological quality. Further research is needed to attempt to quantify the efficacy of castor oil as an cervical priming and induction agent.

Morning versus evening induction of labour for improving outcomes

BACKGROUND

Induction of labour is a common intervention in obstetric practice. Traditionally, in most hospitals induction of labour with medication starts early in the morning, with the start of the working day for the day shift. In human and animal studies spontaneous onset of labour is proven to have a circadian rhythm with a preference for start of labour in the evening. Moreover, when spontaneous labour starts in the evening, the total duration of labour and delivery shortens and fewer obstetric interventions are needed. Based on these observations one might assume that starting induction of labour in the evening, in harmony with the circadian rhythm of natural birth, is more beneficial for both mother and child.

OBJECTIVES

To assess whether induction of labour starting in the evening, coinciding with the endogenous circadian rhythm, improves the outcome of labour compared with induction of labour starting in the early morning, organised to coincide with office hours.

SEARCH METHODS

We contacted the Trials Search Co-ordinator to search the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2012). In addition, we searched MEDLINE (1966 to 16 February 2012) and EMBASE (1980 to 16 February 2012).

SELECTION CRITERIA

We included all published and unpublished randomised controlled trials. We excluded trials that employed quasi-random methods of treatment allocation.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias. Two review authors independently extracted data. Data were checked for accuracy. Where necessary, we contacted study authors for additional information.

MAIN RESULTS

The search resulted in 2693 articles that we screened on title and abstract for eligibility.Thirteen studies were selected for full text assessment. We included three randomised trials involving 1150 women. Two trials compared the administration of prostaglandins in the morning versus the evening in women with an unfavourable cervix, and one trial compared induction of labour in the morning versus the evening in women with a favourable cervix and/or ruptured membranes with intravenous oxytocin. Because of the different mechanism, we have reported results for these two comparisons separately.In the two trials comparing prostaglandins in the morning versus the evening there were few clinically significant differences between study groups for maternal or neonatal outcomes. One study reported a statistically significant preference by women to start induction of labour with prostaglandins in the morning.In the trial examining induction of labour with intravenous oxytocin, the number of neonatal admissions was statistically significantly increased in the group of women that started induction in the morning. This finding was unexpected, and while the trial authors offered some possible explanations for this, it is important that any future trials examine neonatal outcomes.

AUTHORS' CONCLUSIONS

Taking into account women's preferences that favoured administration of prostaglandins in the morning, we conclude that caregivers should preferably consider administering prostaglandins in the morning.There is no strong evidence that induction of labour with intravenous oxytocin in the evening is more or less effective than induction in the morning. Consideration may be given to start induction of labour with oxytocin in the evening when indicated.

Pregnancy complicated by morbidly adherent placenta in a patient with bilateral ovarian agenesis: a case report

The author presents a case of in vitro fertilization pregnancy complicated by morbidly adherent placenta in a patient with congenital bilateral ovarian agenesis. A 31-year-old woman with congenital bilateral ovarian agenesis who had undergone two previous dilatation and curettage procedures conceived following in vitro fertilization with a donor egg. Spontaneous labor occurred at 38 weeks and 5 days’ gestation. The labor was augmented in the active phase and resulted in instrumental vaginal delivery. The third stage was complicated by hemorrhage and retained placenta. Morbidly adherent placenta was diagnosed on attempt at manual removal of the placenta, and the adherent part of the placenta was left in situ. This was removed uneventfully at 5 weeks following childbirth when there was no blood flow observed between the placenta and the myometrium on Doppler ultrasound examination. In conclusion, successful parturition is possible in patients with congenital bilateral ovarian agenesis. When morbidly adherent placenta is managed conservatively, the placenta may be safely removed if there is no vascularity between the placenta and the myometrium.

Mechanical methods for induction of labour

BACKGROUND

Mechanical methods were the first methods developed to ripen the cervix and induce labour. During recent decades they have been substituted by pharmacological methods. Potential advantages of mechanical methods, compared with pharmacological methods, may include simplicity of preservation, lower cost and reduction of the side effects.

OBJECTIVES

To determine the effects of mechanical methods for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment, prostaglandins (vaginal and intracervical prostaglandin E2 (PGE2), misoprostol) and oxytocin.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and bibliographies of relevant papers. We updated this search on 16 January 2012 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

Clinical trials comparing mechanical methods used for third trimester cervical ripening or labour induction with methods listed above it on a predefined list of methods of labour. A comparison with amniotomy will be added, should this comparison be made in future trials.Different types of intervention have been considered as mechanical methods: (1) introduction of laminaria tents, or their synthetic equivalent (Dilapan), into the cervical canal; (2) the introduction of a catheter through the cervix into the extra-amniotic space, with or without traction; (3) use of a catheter to inject fluidsin the extra-amniotic spaceIn addition, we made other comparisons: (1) specific mechanical methods (balloon catheter and laminaria tents) compared with any prostaglandins or with oxytocin; (2) addition of prostaglandins or oxytocin to mechanical methods compared with prostaglandins alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data.

MAIN RESULTS

For this update we have included a further 27 studies. The review includes 71 randomised controlled trials (total of 9722 women), ranging from 39 to 588 women per study. Most studies reported on caesarean section, all other outcomes are based on substantially fewer women. Four additional studies are ongoing.Mechanical methods versus no treatment: one study (48 woman) reported on women who did not achieve vaginal delivery within 24 hours (risk ratio (RR) 0.90; 95% confidence interval (CI) 0.64 to 1.26). The risk of caesarean section was similar between groups (six studies; 416 women, RR 1.00; 95% CI 0.76 to 1.30). There were no cases of severe neonatal and maternal morbidity.Mechanical methods versus vaginal PGE2 (17 studies;1894 woman): The proportion of women who did not achieve vaginal delivery within 24 hours was not significantly different (three studies; 586 women RR 1.72; 95% CI 0.90 to 3.27); however, for the subgroup of multiparous women the risk of not achieving delivery within 24 hours was higher (one study; 147 women RR 4.38, 95% CI 1.74 to 10.98), with no increase in caesarean sections (RR 1.19, 95% CI 0.62-2.29). Compared with intracervical PGE2 (14 studies;1784 women and misoprostol there was no significant difference in the proportion of women not achieving vaginal delivery within 24 hours.Mechanical methods reduced the risk of hyperstimulation with fetal heart rate changes when compared with vaginal prostaglandins: vaginal PGE2 (eight studies; 1203 women, RR 0.16; 95% CI 0.06 to 0.39) and misoprostol (3% versus 9%) (nine studies; 1615 women, RR 0.37; 95% CI 0.25 to 0.54). Risk of caesarean section between mechanical methods and prostaglandins was comparable. Serious neonatal and maternal morbidity were infrequently reported and did not differ between the groups.Mechanical methods compared with induction with oxytocin (reduced the risk of caesarean section (five studies; 398 women, RR 0.62; 95% CI 0.42 to 0.90). The likelihood of vaginal delivery within 24 hours was not reported. Hyperstimulation with fetal heart rate changes was reported in one study (200 participants), and did not differ. There were no reported cases of severe maternal or neonatal morbidity.

AUTHORS' CONCLUSIONS

Induction of labour using mechanical methods results in similar caesarean section rates as prostaglandins, for a lower risk of hyperstimulation. Mechanical methods do not increase the overall number of women not delivered within 24 hours, however the proportion of multiparous women who did not achieve vaginal delivery within 24 hours was higher when compared with vaginal PGE2. Compared with oxytocin, mechanical methods reduce the risk of caesarean section.

Methods of induction of labour: a systematic review

BACKGROUND

Rates of labour induction are increasing. We conducted this systematic review to assess the evidence supporting use of each method of labour induction.

METHODS

We listed methods of labour induction then reviewed the evidence supporting each. We searched MEDLINE and the Cochrane Library between 1980 and November 2010 using multiple terms and combinations, including labor, induced/or induction of labor, prostaglandin or prostaglandins, misoprostol, Cytotec, 16,16,-dimethylprostaglandin E2 or E2, dinoprostone; Prepidil, Cervidil, Dinoprost, Carboprost or hemabate; prostin, oxytocin, misoprostol, membrane sweeping or membrane stripping, amniotomy, balloon catheter or Foley catheter, hygroscopic dilators, laminaria, dilapan, saline injection, nipple stimulation, intercourse, acupuncture, castor oil, herbs. We performed a best evidence review of the literature supporting each method. We identified 2048 abstracts and reviewed 283 full text articles. We preferentially included high quality systematic reviews or large randomised trials. Where no such studies existed, we included the best evidence available from smaller randomised or quasi-randomised trials.

RESULTS

We included 46 full text articles. We assigned a quality rating to each included article and a strength of evidence rating to each body of literature. Prostaglandin E2 (PGE2) and vaginal misoprostol were more effective than oxytocin in bringing about vaginal delivery within 24 hours but were associated with more uterine hyperstimulation. Mechanical methods reduced uterine hyperstimulation compared with PGE2 and misoprostol, but increased maternal and neonatal infectious morbidity compared with other methods. Membrane sweeping reduced post-term gestations. Most included studies were too small to evaluate risk for rare adverse outcomes.

CONCLUSIONS

Research is needed to determine benefits and harms of many induction methods.

Vaginal misoprostol for cervical ripening and induction of labour

BACKGROUND

Misoprostol (Cytotec, Searle) is a prostaglandin E1 analogue widely used for off-label indications such as induction of abortion and of labour. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of vaginal misoprostol for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008) and bibliographies of relevant papers. We updated this search on 30 April 2010 and added the results to the awaiting classification section.

SELECTION CRITERIA

Clinical trials comparing vaginal misoprostol used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

We developed a strategy to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.We used fixed-effect Mantel-Haenszel meta-analysis for combining dichotomous data.If we identified substantial heterogeneity (I² greater than 50%), we used a random-effects method.

MAIN RESULTS

We included 121 trials. The risk of bias must be kept in mind as only 13 trials were double blind.Compared to placebo, misoprostol was associated with reduced failure to achieve vaginal delivery within 24 hours (average relative risk (RR) 0.51, 95% confidence interval (CI) 0.37 to 0.71). Uterine hyperstimulation, without fetal heart rate (FHR) changes, was increased (RR 3.52 95% CI 1.78 to 6.99).Compared with vaginal prostaglandin E2, intracervical prostaglandin E2 and oxytocin, vaginal misoprostol was associated with less epidural analgesia use, fewer failures to achieve vaginal delivery within 24 hours and more uterine hyperstimulation. Compared with vaginal or intracervical prostaglandin E2, oxytocin augmentation was less common with misoprostol and meconium-stained liquor more common.Lower doses of misoprostol compared to higher doses were associated with more need for oxytocin augmentation and less uterine hyperstimulation, with and without FHR changes.We found no information on women's views.

AUTHORS' CONCLUSIONS

Vaginal misoprostol in doses above 25 mcg four-hourly was more effective than conventional methods of labour induction, but with more uterine hyperstimulation. Lower doses were similar to conventional methods in effectiveness and risks. The authors request information on cases of uterine rupture known to readers. The vaginal route should not be researched further as another Cochrane review has shown that the oral route of administration is preferable to the vaginal route. Professional and governmental bodies should agree guidelines for the use of misoprostol, based on the best available evidence and local circumstances.

Intravenous oxytocin alone for cervical ripening and induction of labour

BACKGROUND

Oxytocin is the commonest induction agent used worldwide. It has been used alone, in combination with amniotomy or following cervical ripening with other pharmacological or non-pharmacological methods.

OBJECTIVES

To determine the effects of oxytocin alone for third trimester cervical ripening and induction of labour in comparison with other methods of induction of labour or placebo/no treatment.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2009) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing intravenous oxytocin with placebo or no treatment, or with prostaglandins (vaginal or intracervical) for third trimester cervical ripening or labour induction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and carried out data extraction.

MAIN RESULTS

Sixty-one trials (12,819 women) are included.When oxytocin inductions were compared with expectant management, fewer women failed to deliver vaginally within 24 hours (8.4% versus 53.8%, risk ratio (RR) 0.16, 95% confidence interval (CI) 0.10 to 0.25). There was a significant increase in the number of women requiring epidural analgesia (RR 1.10, 95% CI 1.04 to 1.17). Fewer women were dissatisfied with oxytocin induction in the one trial reporting this outcome (5.9% versus 13.7%, RR 0.43, 95% CI 0.33 to 0.56).Compared with vaginal prostaglandins, oxytocin increased unsuccessful vaginal delivery within 24 hours in the two trials reporting this outcome (70% versus 21%, RR 3.33, 95% CI 1.61 to 6.89). There was a small increase in epidurals when oxytocin alone was used (RR 1.09, 95% CI 1.01 to 1.17).Most of the studies included women with ruptured membranes, and there was some evidence that vaginal prostaglandin increased infection in mothers (chorioamnionitis RR 0.66, 95% CI 0.47 to 0.92) and babies (use of antibiotics RR 0.68, 95% CI 0.53 to 0.87). These data should be interpreted cautiously as infection was not pre-specified in the original review protocol.When oxytocin was compared with intracervical prostaglandins, there was an increase in unsuccessful vaginal delivery within 24 hours (50.4% versus 34.6%, RR 1.47, 95% CI 1.10 to 1.96) and an increase in caesarean sections (19.1% versus 13.7%, RR 1.37, 95% CI 1.08 to 1.74) in the oxytocin group.

AUTHORS' CONCLUSIONS

Comparison of oxytocin with either intravaginal or intracervical PGE2 reveals that the prostaglandin agents probably increase the chances of achieving vaginal birth within 24 hours. Oxytocin induction may increase the rate of interventions in labour.A suggestion that for women with prelabour rupture of membranes induction with vaginal prostaglandin may increase risk of infection for mother and baby warrants further study.

Mifepristone for induction of labour

BACKGROUND

The steroid hormone, progesterone, inhibits contractions of the pregnant uterus at all gestations. Antiprogestins (including mifepristone) have been developed to antagonise the action of progesterone, and have a recognised role in medical termination of early or mid-trimester pregnancy. Animal studies have suggested that mifepristone may also have a role in inducing labour in late pregnancy.

OBJECTIVES

To determine the effects of mifepristone for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register and reference lists of relevant papers (May 2009).

SELECTION CRITERIA

Clinical trials comparing mifepristone used for third trimester cervical ripening or labour induction with placebo/no treatment or other labour induction methods.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. For this update, two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

Ten trials (1108 women) are included. Compared to placebo, mifepristone treated women were more likely to be in labour or to have a favourable cervix at 48 hours (risk ratio (RR) 2.41, 95% confidence intervals (CI) 1.70 to 3.42) and this effect persisted at 96 hours (RR 3.40, 95% CI 1.96 to 5.92). They were less likely to need augmentation with oxytocin (RR 0.80, 95% CI 0.66 to 0.97). Mifepristone treated women were less likely to undergo caesarean section (RR 0.74, 95% CI 0.60 to 0.92) but more likely to have an instrumental delivery (RR 1.43, 95% CI 1.04 to 1.96). Women receiving mifepristone were less likely to undergo a caesarean section as a result of failure to induce labour (RR 0.40, 95% CI 0.20 to 0.80). There is insufficient evidence to support a particular dose but a single dose of 200 mg mifepristone appears to be the lowest effective dose for cervical ripening (increased likelihood of cervical ripening at 72 hours (RR 2.13, 95% CI 1.15 to 3.97). Abnormal fetal heart rate patterns were more common after mifepristone treatment (RR 1.85, 95% CI 1.17 to 2.93), but there was no evidence of differences in other neonatal outcomes. There is insufficient information on the occurrence of uterine rupture/dehiscence in the reviewed studies.

AUTHORS' CONCLUSIONS

There is insufficient information available from clinical trials to support the use of mifepristone to induce labour. However, the studies suggest that mifepristone is better than placebo in reducing the likelihood of caesarean sections being performed for failed induction of labour; therefore, this may justify future trials comparing mifepristone with the routine cervical ripening agents currently in use. There is little information on effects on the baby.

Morning versus evening induction of labour for improving outcomes

This is the protocol for a review and there is no abstract. The objectives are as follows: To assess whether induction of labour starting in the evening, coinciding with the endogenous circadian rhythm, improves the outcome of labour compared to induction of labour starting in the early morning, organised to coincide with office hours.

Hyaluronidase for cervical ripening and induction of labour

BACKGROUND

Dilatation and effacement of the cervix are not only a result of uterine contractions, but are also dependent upon ripening processes within the cervix. The cervix is a fibrous organ composed principally of hyaluronic acid, collagen and proteoglycan. Hyaluronic acid increases markedly after the onset of labour. An increase in the level of hyaluronic acid is associated with an increase in tissue water content. Cervical ripening during labour is characterised by changes of the cervix and an increased water content. Cervical injection of hyaluronidase was postulated to increase cervical ripening. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of hyaluronidase for third trimester cervical ripening or induction of labour in comparison with other methods of induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (January 2006) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials of hyaluronidase for third trimester cervical ripening or labour induction.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. We assessed trial quality. We contacted study authors for additional information. We collected adverse effects information from the trials.

MAIN RESULTS

One trial, with 168 women participating, was included in the review. When compared with placebo for cervical ripening intracervical injections of hyaluronidase resulted in women receiving significantly fewer caesarean sections (18% versus 49%, relative risk (RR) 0.37, 95% confidence interval (CI) 0.22 to 0.61), less need for oxytocin augmentation (10% versus 47%, RR 0.20, 95% CI 0.10 to 0.41), and increased cervical favourability after 24 hours (60% versus 98%, RR 0.62, 95% CI 0.52 to 0.74). No side-effects for mother or baby were reported in this trial.

AUTHORS' CONCLUSIONS

Intracervical injections of hyaluronidase for cervical ripening appear beneficial. However, this is not common practice. In addition it is an invasive procedure that women may find unacceptable in the presence of less invasive methods.

Breast stimulation for cervical ripening and induction of labour

BACKGROUND

Breast stimulation has been suggested as a means of inducing labour. It is a non-medical intervention allowing women greater control over the induction process. This is one of a series of reviews of methods of cervical ripening and labour induction using a standardised methodology.

OBJECTIVES

To determine the effectiveness of breast stimulation for third trimester cervical ripening or induction of labour in comparison with placebo/no intervention or other methods of induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Trials Register (March 2004) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials of breast stimulation for third trimester cervical ripening or labour induction.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

MAIN RESULTS

Six trials (719 women) were included. Analysis of trials comparing breast stimulation with no intervention found a significant reduction in the number of women not in labour at 72 hours (62.7% versus 93.6%, relative risk (RR) 0.67, 95% confidence interval (CI) 0.60 to 0.74). This result was not significant in women with an unfavourable cervix. A major reduction in the rate of postpartum haemorrhage was reported (0.7% versus 6%, RR 0.16, 95% CI 0.03 to 0.87). No significant difference was detected in the caesarean section rate (9% versus 10%, RR 0.90, 95% CI 0.38 to 2.12) or rates of meconium staining. There were no instances of uterine hyperstimulation. Three perinatal deaths were reported (1.8% versus 0%, RR 8.17, 95% CI 0.45 to 147.77). When comparing breast stimulation with oxytocin alone the analysis found no difference in caesarean section rates (28% versus 47%, RR 0.60, 95% CI 0.31 to 1.18). No difference was detected in the number of women not in labour after 72 hours (58.8% versus 25%, RR 2.35, 95% CI 1.00 to 5.54) or rates of meconium staining. There were four perinatal deaths (17.6% versus 5%, RR 3.53, 95% CI 0.40 to 30.88).

AUTHORS' CONCLUSIONS

Breast stimulation appears beneficial in relation to the number of women not in labour after 72 hours, and reduced postpartum haemorrhage rates. Until safety issues have been fully evaluated it should not be used in high-risk women. Further research is required to evaluate its safety, and should seek data on postpartum haemorrhage rates, number of women not in labour at 72 hours and maternal satisfaction.

Interleukin-8 is involved in cervical dilatation but not in prelabour cervical ripening

Our aim was to determine the amount and source of interleukin (IL)-8 and to study IL-8 receptor expression in the human cervix during pregnancy and after labour. Cervical biopsies were obtained from six non-pregnant women, eight women undergoing pregnancy termination, 17 women undergoing elective caesarean section and 11 women after vaginal delivery. IL-8 levels were compared in women with and without a ripe cervix, as determined by cervical Bishop score and cervicovaginal fetal fibronectin levels. Levels of IL-8 and IL-1beta, a regulator of IL-8 expression, were determined by enzyme-linked immunosorbent assay (ELISA). IL-8, IL-1beta and IL-8 receptor proteins were localized by immunohistochemistry. Compared with late pregnancy, IL-8 levels increased after labour and vaginal delivery (P < 0.01) but there was no correlation with cervical ripening. IL-8 was localized to stromal cells, macrophages and granulocytes. There were no significant differences in IL-1beta levels between groups. IL-8 receptors were expressed primarily on granulocytes and macrophages after vaginal delivery. We conclude that IL-8 is involved in cervical dilatation but not in cervical ripening.

Oestrogens alone or with amniotomy for cervical ripening or induction of labour

BACKGROUND

Studies in sheep showed that there is a pre-labour rise in oestrogen and a decrease in progesterone, both of these changes stimulate prostaglandin production and may help initiate labour. Though oestrogen has been suggested as an effective cervical ripening or induction agent, research in humans have failed to demonstrate a similar physiological mechanism. The use of oestrogen as an induction agent is not currently common practice, as such this systematic review should be regarded as an historical review. This is one of a series of reviews of methods of cervical ripening and labour induction using a standardised methodology.

OBJECTIVES

To determine, from the best available evidence, the effectiveness and safety of oestrogens alone or with amniotomy for third trimester cervical ripening and induction of labour in comparison with other methods of induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: April 2001.

SELECTION CRITERIA

(1) randomised controlled trials comparing oestrogens alone used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A generic strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally.

MAIN RESULTS

When comparing oestrogen with placebo there was no difference between the rate of caesarean section (7.1% versus 10.3%, relative risk (RR) 0.70, 95% confidence interval (CI) 0.30,1.62). There were no differences between rates of uterine hyperstimulation with or without fetal heart rate changes or instrumental vaginal delivery. None of the studies reported the rates of either vaginal delivery not achieved in 24 hours, or cervix unfavourable/unchanged after 12-24 hours. There were insufficient data to make any meaningful conclusions when comparing oestrogen with vaginal PGE2, intracervical PGE2, oxytocin alone or extra amniotic PGF2a, as to whether oestrogen is effective in inducing labour.

REVIEWER'S CONCLUSIONS

There were insufficient data to draw any conclusions regarding the efficacy of oestrogen as an induction agent.

Extra-amniotic prostaglandin for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of extra-amniotic prostaglandin for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Date of last search: December 2000.

SELECTION CRITERIA

(1) clinical trials comparing extra-amniotic prostaglandin used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This has involved a two-stage method of data extraction. The initial data were extracted centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology.

MAIN RESULTS

Oxytocin was used to initiate or augment labour significantly less frequently with extra-amniotic prostaglandins when compared to placebo (relative risk 0.50, 95% confidence interval 0.38-0.66). No other findings were significant in the comparisons that were made for this review including when extra-amniotic prostaglandins were compared with other methods of cervical ripening or induction of labour. Although this could suggest that extra-amniotic prostaglandins are as effective as other agents, the findings are difficult to interpret because they are based on very small numbers and may lack the power to show a real difference.

REVIEWER'S CONCLUSIONS

The studies in this review are limited by their small sample sizes which are in many cases further divided into multiple comparison groups. The analyses resulted in most comparisons showing no significant differences, with wide confidence intervals. Although extra-amniotic prostaglandins may be as effective as other modalities in initiating labour, there is little conclusive information from this review to guide clinical practice. An adequately powered randomised controlled trial would be useful to determine if the use of extra-amniotic prostaglandins would lower the rate of caesarean section. However, in the time since these studies were undertaken the use of extra-amniotic prostaglandins has largely been replaced by other modes of prostaglandin administration.

Oral prostaglandin E2 for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of oral prostaglandin E2 for third trimester induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Date of last search: December 2000.

SELECTION CRITERIA

The criteria for inclusion included the following: (1) clinical trials comparing oral prostaglandin E2 used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involves a two-stage method of data extraction. The initial data extraction is done centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data will then be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman. To avoid duplication of data in the primary reviews, the labour induction methods have been listed in a specific order, from one to 25. Each primary review includes comparisons between one of the methods (from two to 25) with only those methods above it on the list.

MAIN RESULTS

There were 19 studies included in the review. Of these 15 included a comparison using either oral or intravenous oxytocin with or without amniotomy. The quality of studies reviewed was not high. Only seven studies had clearly described allocation concealment. Only two studies stated that providers and/or participants were blinded to treatment group. For the outcome of vaginal delivery not achieved within 24 hours, in the composite comparison of oral PGE2 versus all oxytocin treatments (oral and intravenous, with and without amniotomy), there was a trend favoring oxytocin treatments (relative risk (RR) 1.97, 95% confidence interval (CI) 0.86 to 4.48). For the outcome of cesarean section, in the comparison of PGE2 versus no treatment or placebo, PGE2 was favored (relative risk (RR) 0.54, 95% confidence interval (CI) 0.29,0.98). Otherwise, there were no significant differences between groups for this outcome. Oral prostaglandin was associated with vomiting across all comparison groups.

REVIEWER'S CONCLUSIONS

Oral prostaglandin consistently resulted in more frequent gastrointestinal side effects, in particular vomiting, compared with the other treatments included in this review. There were no clear advantages to oral prostaglandin over other methods of induction of labour.

Homoeopathy for induction of labour

BACKGROUND

This is one of series of reviews of cervical ripening and labour induction using standardised methodology. Homoeopathy involves the use, in dilution, of substances which cause symptoms in their undiluted form. A type of herb, 'caulophyllum' is one type of homoeopathic therapy that has been used to induce labour.

OBJECTIVES

To determine the effects of homoeopathy for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: March 2001.

SELECTION CRITERIA

Randomised controlled trials comparing homeopathy used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

A generic strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally.

MAIN RESULTS

One trial involving 40 women was included in the review. This trial was placebo controlled and double blind, but the quality was not high. Insufficient information was available on the method of randomisation and the study lacked clinically meaningful outcomes. This trial demonstrated no differences in any outcome between the treatment and control group.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to recommend the use of caulophyllum as a method of induction. It is likely that the demand for complementary medicine will continue and women will continue to consult a homoeopath during their pregnancy. Although caulophyllum is a commonly used homoeopathic therapy to induce labour, the treatment strategy used in this trial may not reflect routine practice of homoeopathy. It may be more appropriate to undertake further evaluation of individualised homeopathic therapies for induction of labour in future clinical trials.

Amniotomy alone for induction of labour

BACKGROUND

Amniotomy (deliberate rupture of the membranes) is a simple procedure which can be used alone for induction of labour if the membranes are accessible, thus avoiding the need for pharmacological intervention. However, the time interval from amniotomy to established labour may not be acceptable to clinicians and women, and in a number of cases labour may not ensue. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of amniotomy alone for third trimester labour induction in women with a live fetus.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled trials register and bibliographies of relevant papers.

SELECTION CRITERIA

The criteria for inclusion included the following: (1) clinical trials comparing amniotomy alone for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random or pseudo-random allocation to the treatment or control group; (3) ideally adequate allocation concealment (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally, and incorporated into the series of primary reviews arranged by methods of induction of labour. The data from the primary reviews will be incorporated into a series of secondary reviews, arranged by category of woman to reflect clinical scenarios. To avoid duplication of data in the primary reviews, the labour induction methods have been listed in a specific order, from one to 25. Each primary review includes comparisons between one of the methods (from two to 25) with only those methods above it on the list. This review includes comparisons between amniotomy alone (number 5 on the list) with only those methods above it on the list (no treatment / placebo; intravaginal prostaglandins; intracervical prostaglandins; and oxytocin alone).

MAIN RESULTS

Two trials comprising 50 and 260 women respectively were eligible for inclusion in this review. No conclusions could be drawn from comparisons of amniotomy alone versus no intervention, and amniotomy alone versus oxytocin alone (small trial, only one pre-specified outcome reported). No trials compared amniotomy alone with intracervical prostaglandins. One trial compared amniotomy alone with a single dose of vaginal prostaglandins for women with a favourable cervix, and found a significant increase in the need for oxytocin augmentation in the amniotomy alone group (44% versus 15%; RR 2.85, 95% CI 1.82-4.46). This should be viewed with caution as this was the result of a single centre trial. Furthermore, secondary intervention occurred 4 hours after amniotomy, and this time interval may not have been appropriate.

REVIEWER'S CONCLUSIONS

Data is lacking about the value of amniotomy alone for induction of labour. While there are now other modern methods available for induction of labour (pharmacological agents), there remain clinical scenarios where amniotomy alone may be desirable and appropriate, and this method is worthy of further research. This research should include evaluation of the appropriate time interval from amniotomy to secondary intervention, women and caregivers' satisfaction and economic analysis.