Intravenous oxytocin alone for cervical ripening and induction of labour

Comparison of Vaginal Dinoprostone Pessary With Transcervical Balloon Catheter Plus Vaginal Misoprostol for Pre-induction Cervical Ripening: A Randomized Trial

Aims and Objectives To compare the safety and efficacy of dinoprostone pessary with Foley plus vaginal misoprostol for cervical ripening. Materials and Methods We randomized 115 women to the pessary or Foley plus misoprostol group. Pessary was inserted for 24 hours, and in the Foley plus misoprostol group, intravaginal misoprostol 25 mcg was administered along with trans-cervical Foley insertion and repeated every six hours to a maximum dose of 100 mcg. Singleton pregnancies requiring labor induction at more than 34 weeks with a Bishop score of <6 were included. Study outcomes included induction-delivery interval (IDI), mode of delivery, change in the Bishop score, need for oxytocin augmentation, and patient discomfort as assessed by visual analog score. Results The IDI was similar between the groups (pessary vs Foley plus misoprostol; 21.27 vs 21.10 hours, p = 0.9). The mean change in the Bishop score and need for augmentation with oxytocin was significantly more in the Foley plus misoprostol group compared to pessary (2.72 vs 1.94, p = 0.001; 89.7% vs 57.9%, p = 0.0001). Pessary was better tolerated compared to Foley plus misoprostol (VAS 7.8 vs 6.68, p = 0.0001). Mode of delivery and maternal and neonatal outcomes showed no difference. Conclusion There was no significant difference between pessary and Foley plus misoprostol in the IDI and mode of delivery. Pessary was better tolerated, and augmentation with oxytocin was required less often. Foley plus misoprostol caused a faster change in the Bishop score, but oxytocin augmentation was used more often. Maternal and neonatal outcomes were similar.

Canine parturition: what is known about the hormonal setting?

Parturition is a challenging physiological process with perfect timing dictated by the events leading to the end of pregnancy in the female, and by the maturation of the fetus(es). The process of parturition remains an intricate interaction of hormones in a fine-tuned timing that remains to be better elucidated in the dog. In the dog pregnancy is maintained by the progesterone production by the corpora lutea, in which some hormones play a luteotrophic action. At term of pregnancy, the pre-parturient luteolytic cascade is the most apparent event, characterized by a rapid decline in plasma progesterone concentrations and useful in predicting the onset of spontaneous parturition. In contrast, cortisol plasma concentrations measurement showed high variability and suggested to be related to the stress condition instead of the onset of parturition. Both prostaglandin F2α and E2 concur in the process of parturition in the dog. The measurement of oxytocin plasma concentrations, also very variable, is implicated in uterine contractions. The measurement of plasma oxytocin concentrations showed to be useful to distinguish between normal and disturbed parturition, allowing the prompt recognition of dystocia and the immediate obstetrical intervention. In contrast to other species, no significant roles of estrogens for the initiating of parturition were demonstrated. Relaxin, the main pregnancy hormonal marker in the dog, beside an endocrine action, is also supposed to play a paracrine/autocrine role at the utero-placental unit and to support the maintenance of high plasma progesterone concentrations through a luteotrophic action, concurring to the main action of prolactin. Although important information has been provided, some aspects in the understanding the hormonal interactions and action timing implications in the process of parturition in the dog remains to be better investigated and represent intriguing topic for basic knowledge and applied research.

Heat and air pollution exposure as triggers of delivery: A survival analysis of population-based pregnancy cohorts in Rome and Barcelona

INTRODUCTION

Environmental exposures have been linked to length of gestation but the question as to during which weeks of gestation pregnancies are most susceptible still remains little explored. We estimated the effect of maximum apparent temperature and air pollution levels on risk of birth by week of gestation.

METHODS

We analyzed two cohorts of singleton live births in Rome (2001-2010) and Barcelona (2007-2012). Maximum apparent temperature (MAT), PM10, O3 and NO2 were analyzed in the warm period (1st April-31st October). Gestational week-specific hazard ratios of giving birth associated to a 1-unit increase in exposure were estimated fitting Cox regression models adjusted for seasonality, and demographic and clinical characteristics of the mother.

RESULTS

We observed 78,633 births (5.5% preterm) in Rome and 27,255 (4.5% preterm) in Barcelona. The highest hazard ratios for 1°C increase in MAT were in the 22nd-26th weeks of gestation, 1.071, (95% CI 1.052-1.091) in Rome and 1.071 (95% CI 1.036-1.106) in Barcelona, and decreased to 1.032 (95% CI 1.026-1.038) and 1.033 (95% CI 1.020-1.045) at the 36th week of gestation, respectively. Similar associations and trends were observed for PM10 and NO2 after adjusting for MAT. O3 showed similar trends but weaker associations.

CONCLUSIONS

We found, consistently in Rome and Barcelona, an increased risk of delivery for a unit increase in MAT, PM10, NO2 and O3, especially in the second half of the second trimester, thus effectively increasing the risk of preterm and particularly early preterm birth. Results may help to increase awareness of these risks among public-health regulators and clinicians, leading to better preventive strategies.

Labor induction utilizing the Foley balloon: a randomized trial comparing standard placement versus immediate removal

OBJECTIVE

To compare time to delivery between two induction procedures. The Foley balloon is a mechanical method for cervical ripening. However, the device may also result in endogenous prostaglandin release following separation of the chorionic membrane and decidua. Prolonged Foley placement may therefore be unnecessary for successful labor induction.

METHOD

Randomized controlled trial of labor induction at LAC+USC Medical Center between 2010 and 2013. Subjects were assigned to either (a) standard placement of the Foley balloon or (b) Foley balloon insufflation and immediate removal. Oxytocin was administered to all subjects not in active labor after 12 h. Delivery information and neonatal outcomes were documented and all patients were followed for 6 weeks for adverse events.

RESULT

A total of 79 women were included in the analysis (37 standard and 42 immediate). Induction time was 8.6 h longer in the immediate removal group (23.5 vs 32.1, P=0.002), but the difference in delivery within 24 h did not meet the statistical significance (46.0 vs 28.6%, P=0.11). Similar rates of cesarean delivery, epidural use and abnormal APGAR scores were observed. After controlling for number of vaginal exams and duration of rupture, a decreased risk of infection was observed in the immediate removal group (odds ratio=0.08, 95% confidence interval=0.007 to 0.93, P=0.04). Further, when the analysis was stratified by parity, differences in induction time only persisted in nulliparous women.

CONCLUSION

Immediate removal of the Foley balloon may lead to longer overall induction time, but a lower risk of infection. Parous women may be particularly good candidates for this type of induction.

Isosorbide Mononitrate a Nitric Oxide Donor: A Study of Its Efficacy and Safety as an Agent for Cervical Ripening

OBJECTIVE

To study the efficacy and safety profile of isosorbide mononitrate (IMN) as an agent for cervical ripening.

METHODOLOGY

This study was conducted in the Department of Obstetrics and Gynecology, M Y Hospital & M G M Medical College Indore from September 2011 to February 2013. Pregnant women attending the antenatal clinics were screened for possible participation in the study after explaining the nature of the study. This study was conducted on 150 patients. An initial dose of 40 mg IMN was applied in the posterior vaginal fornix, and the same dose was repeated after 6 h. Cervical ripening was assessed by the change in Bishop Score 12 h after the initial application.

RESULTS

In a study of 150 cases, mean maternal age was 22.2 ± 2.6 years (range 19-35 years) and mean gestational age was 40.5 ± 1.07 (range 40-42 weeks). 52 women were primigravidas, while 98 were multigravidas. The mean Bishop Score-before drug administration was 1.94 ± 1.3 (range 0-5), and mean fetal heart rate was 137 ± 6.2 bpm. The mean of Bishop scores before IMN administration was 1.94 ± 1.3, while mean of Bishop score after drug administration was 6.7 ± 2.2; mean difference was equal to 4.76. P value was equal to 0.0001. By conventional criteria, this difference is considered to be statistically significant. The mode of delivery 96 (64 %) delivered vaginally, while 54 (36 %) were delivered by Cesarean section. Mean Apgar score at 1 min was 8.2 ± 0.9 SD (range 7-10), while mean Apgar score at 5 min was 9.4 ± 0.6 (range 8-10). The only side effect noted was headache, and 30 cases (20 %) complained of headache.

CONCLUSION

IMN seems to be effective, safe, inexpensive, and well-tolerated agent for cervical ripening. It is cost effective and safe with minimal side effects.

Acupuncture for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. The use of complementary therapies is increasing and some women 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. The limited observational studies to date suggest acupuncture for induction of labour appears safe, 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 the effectiveness and safety of acupuncture for third trimester cervical ripening or induction of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 November 2012), PubMed (1966 to 23 November 2012), Embase (1980 to 23 November 2012), Dissertation Abstracts (1861 to 23 November 2012), CINAHL (1982 to 23 November 2012), the WHO International Clinical Trials Registry Portal (ICTRP) (23 November 2012) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing acupuncture 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

Two review authors independently assessed trials for inclusion, evaluated methodological quality and extracted data.

MAIN RESULTS

The original review included three trials and seven trials were excluded. This updated review includes 14 trials, and excludes eight trials. Three trials previously excluded due to no clinically relevant outcomes are now included. Eight new trials were included, and four new trials were excluded. We included 14 trials with data reporting on 2220 women.Trials reported on three primary outcomes only caesarean section, serious neonatal morbidity and maternal mortality. No trial reported on vaginal delivery not achieved within 24 hours; and uterine hyperstimulation with fetal heart rate (FHR) changes. There was no difference in caesarean deliveries between acupuncture and the sham control (average risk ratio (RR) 0.95, 95% confidence interval (CI) 0.69 to 1.30, six trials, 654 women), and acupuncture versus usual care (average RR 0.69, 95% CI 0.40, 1.20, six trials, 361 women). There was no difference in neonatal seizures between acupuncture and the sham group (RR 1.01, 95% CI 0.06 to 16.04, one trial, 364 women).There was some evidence of a change in cervical maturation for women receiving acupuncture compared with the sham control, (mean difference (MD) 0.40. 95%CI 0.11 to 0.69, one trial, 125 women), and when compared with usual care (MD 1.30, 95% CI 0.11 to 2.49, one trial, 67 women). The length of labour was shorter in the usual care group compared with acupuncture (average standardised mean difference (SMD) 0.67, 95% CI 0.18 to 1.17, one trial 68 women). There were no other statistically significant differences between groups. Few studies reported on many clinically relevant outcomes. One trial was at a low risk of bias on all domains.

AUTHORS' CONCLUSIONS

Overall, there have been few studies assessing the role of acupuncture for induction of labour. Before implications for clinical practice can be made there is a need for well-designed randomised controlled trials to evaluate the role of acupuncture to induce labour and for trials to assess clinically meaningful outcomes.

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.

Oxytocin and catechol-O-methyltransferase receptor genotype predict the length of the first stage of labor

OBJECTIVE

We aimed to identify genetic factors that influence the rate of the first stage of labor.

STUDY DESIGN

We prospectively enrolled 233 laboring nulliparous parturients. Demographic, clinical, and genetic data were collected. We evaluated the influence of population and individual variability using a nonlinear mixed effects model.

RESULTS

Parturients who were homozygous for "G" at oxytocin receptor gene rs53576 transitioned to active labor later and thus had slower labor. Catechol-O-methyltransferase rs4633 genotype TT was associated with slower latent phase labor. Labor induction with prostaglandin was associated with faster labor, and request for meperidine was associated with slower labor. Birthweight was related inversely to the rate of the active phase.

CONCLUSION

There are demographic, clinical, and genetic factors that influence an individual's rate of labor progress. This information could be used in automated form to improve the prediction of the length of the first stage of labor.

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.

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.Induction of labour occurs in approximately 20% of pregnancies in the UK. The ideal agent for induction of labour would induce cervical ripening without causing uterine contractions. Currently most commonly used cervical ripening or induction agents result in uterine activity or contractions, or both. Cervical ripening without uterine contractility could occur safely in an outpatient setting and it may be expected that this would result in greater maternal satisfaction and lower costs.

OBJECTIVES

To determine the effects of nitric oxide (NO) donors for third trimester cervical ripening or induction of labour, in comparison with placebo or no treatment or other treatments from a predefined hierarchy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2010) and the reference lists of trial reports and reviews.

SELECTION CRITERIA

Clinical trials comparing NO donors for cervical ripening or labour induction to other methods listed above it on a predefined list of methods of labour induction. The trials include some form of random allocation to either group; and report one or more of the prestated outcomes. NO donors (isosorbide mononitrate, nitroglycerin and sodium nitroprusside) are compared to 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. Three review authors independently assessed trials for inclusion, assessed risk of bias and extracted data.

MAIN RESULTS

We considered 19 trials; we included 10 (including a total of 1889 women) trials, excluded eight trials and one trial report is awaiting classification. Included studies compared NO donors to placebo, vaginal prostaglandin E2, intracervical PGE2 and vaginal misoprostol. All included studies were of a generally high standard with a low risk of bias.There are very limited data available to compare nitric oxide donors to any other induction agent. There is no evidence of any difference between any of the prespecified outcomes when comparing NO donors to other induction agents, with the exception of an increase in maternal side effects.

AUTHORS' CONCLUSIONS

NO donors do not appear currently to be a useful tool in the process of induction of labour. More studies are required to examine how NO donors may work alongside established induction of labour protocols, especially those based in outpatient settings.

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.

Misoprostol for induction of labour to terminate pregnancy in the second or third trimester for women with a fetal anomaly or after intrauterine fetal death

BACKGROUND

A woman may need to give birth prior to the spontaneous onset of labour in situations where the fetus has died in utero (also called a stillbirth), or for the termination of pregnancy where the fetus, if born alive would not survive or would have a permanent handicap. Misoprostol is a prostaglandin medication that can be used to induce labour in these situations.

OBJECTIVES

To compare the benefits and harms of misoprostol to induce labour to terminate pregnancy in the second and third trimester for women with a fetal anomaly or after intrauterine fetal death when compared with other methods of induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2009).

SELECTION CRITERIA

Randomised controlled trials comparing misoprostol with placebo or no treatment, or any other method of induction of labour, for women undergoing induction of labour to terminate pregnancy in the second and third trimester following an intrauterine fetal death or for fetal anomalies.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 38 studies (3679 women).Nine studies included pregnancies after intrauterine deaths, five studies included termination of pregnancies because of fetal anomalies when the fetus was still alive and the rest (24) presented the pooled data for intrauterine deaths, fetal anomalies and social reasons.When compared with agents that have traditionally been used to induce labour in this setting (for example, gemeprost, prostaglandin E(2) and prostaglandin F(2alpha)), vaginal misoprostol is as effective in ensuring vaginal birth within 24 hours, with a similar induction to birth interval. Vaginal misoprostol is associated with a reduction in the occurrence of maternal gastrointestinal side effects such as nausea, vomiting and diarrhoea when compared with other prostaglandin preparations. While the different treatments involving various prostaglandin preparations appear comparable for the reported outcomes, the information available regarding rare maternal complications, such as uterine rupture, is limited.

AUTHORS' CONCLUSIONS

The use of vaginal misoprostol in the termination of second and third trimester of pregnancy is as effective as other prostaglandin preparations (including cervagem, prostaglandin E(2) and prostaglandin F(2alpha)), and more effective than oral administration of misoprostol. However, important information regarding maternal safety, and in particular the occurrence of rare outcomes such as uterine rupture, remains limited. Future research efforts should be directed towards determining the optimal dose and frequency of administration, with particular attention to standardised reporting of all relevant outcomes and assessment of rare adverse events. Further information is required about the use of sublingual misoprostol in this setting.

Induction of labor with vaginal misoprostol plus oxytocin versus oxytocin alone

OBJECTIVE

To compare the effect of an oxytocin infusion alone or preceded by an intravaginal application of misoprostol for labor induction in women with term pregnancies and a low Bishop score.

METHODS

This study randomized 100 multiparous women with singleton pregnancies over 38 weeks and a Bishop score less than 6 to receive either a single 50-microg dose of misoprostol intravaginally 3 hours before initiation of the oxytocin infusion or only an oxytocin infusion. The time from induction to delivery, the route of delivery, and maternal and fetal outcomes were analyzed.

RESULTS

The mean time from induction to delivery was 9.36+/-1.97 hours in the misoprostol plus oxytocin group and 11.08+/-3.23 in the oxytocin alone group (P=0.002). The rates of vaginal delivery, 1- and 5-minute Agpar scores, placental abruption, and postpartum hemorrhage were similar between the 2 groups, as were the rates of admission to the neonatal intensive care unit. There were no cases of perinatal asphyxia.

CONCLUSION

A 50-microg intravaginal application of misoprostol before starting the oxytocin infusion is a more effective method of labor induction than an oxytocin infusion alone for our study population.

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.

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

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. Initial work focused on prostaglandin F2a as prostaglandin E2 was considered unsuitable for a number of reasons. With the development of alternative routes of administration, comparisons were made between various formulations of vaginal prostaglandins.

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 STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009) 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 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

Sixty-three (10,441 women) have been included.Vaginal prostaglandin E2 compared with placebo or no treatment reduced the likelihood of vaginal delivery not being achieved within 24 hours (18.1% versus 98.9%, risk ratio (RR) 0.19, 95% confidence interval (CI) 0.14 to 0.25, two trials, 384 women). The risk of the cervix remaining unfavourable or unchanged was reduced (21.6% versus 40.3%, RR 0.46, 95% CI 0.35 to 0.62, five trials, 467 women); and the risk of oxytocin augmentation reduced (35.1% versus 43.8%, RR 0.83, 95% CI 0.73 to 0.94, 12 trials, 1321 women) when PGE2 was compared to placebo. There was no evidence of a difference between caesarean section rates, although the risk of uterine hyperstimulation with fetal heart rate changes was increased (4.4% versus 0.49%, RR 4.14, 95% CI 1.93 to 8.90, 14 trials, 1259 women).PGE2 tablet, gel and pessary appear to be as efficacious as each other and the use of sustained release PGE2 inserts appear to be associated with a reduction in instrumental vaginal delivery rates (9.9 % versus 19.5%, RR 0.51, 95% CI 0.35 to 0.76, NNT 10 (6.7 to 24.0), five trials, 661 women) when compared to vaginal PGE2 gel or tablet.

AUTHORS' CONCLUSIONS

PGE2 increases successful vaginal delivery rates in 24 hours and cervical favourability with no increase in operative delivery rates. Sustained release vaginal PGE2 is superior to vaginal PGE2 gel with respect to some outcomes studied.Further research is needed to assess the best vehicle for delivering vaginal prostaglandins and this should, where possible, include some examination of the cost-analysis.

What (not) to do before delivery? Prevention of fetal meconium release and its consequences

BACKGROUND

Meconium-stained amniotic fluid is a common occurrence which places the mother at risk of escalating obstetric interventions, and the baby at risk of meconium aspiration syndrome.

METHODS

The Cochrane Library was searched for interventions related to care before delivery with useful evidence on the outcomes 'meconium-stained amniotic fluid' and 'meconium aspiration syndrome'.

FINDINGS

Curtailment of post-term pregnancy reduces the occurrence of meconium-stained amniotic fluid, and meconium aspiration syndrome. Uterine stimulants, particularly misoprostol, are associated with occurrence of meconium-stained amniotic fluid. Amniotomy during labour may be a risk factor for meconium aspiration syndrome. There is little research evidence on the benefits or otherwise of obstetric interventions such as expedited delivery for meconium-stained liquor without other evidence of fetal distress. Amnioinfusion for meconium-stained amniotic fluid improves neonatal outcome only in settings with limited peripartum surveillance. There is insufficient evidence to support the use of amnioinfusion for meconium-stained liquor in settings with adequate peripartum surveillance.

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.

Intracervical prostaglandins for induction of labour

BACKGROUND

Prostaglandins have been used for cervical ripening and induction of labour since the 1970s. The goal of the administration of prostaglandins in the process of induction of labour is to achieve cervical ripening before the onset of contractions. One of the routes of administration that was proposed is intracervical. Using this route, prostaglandins are less easy to administer and the need for exposing the cervix may cause discomfort to the woman.

OBJECTIVES

To determine the effects of intracervical prostaglandins for third trimester cervical ripening or induction of labour compared with placebo/no treatment and with vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2007) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing intracervical prostaglandins 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 (vaginal prostaglandins, except misoprostol).

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

Fifty-six trials (7738 women) are included. INTRACERVICAL PGE2 WITH PLACEBO/NO TREATMENT: 28 TRIALS, 3764 WOMEN: Four studies reported the number of women who did not achieve vaginal delivery within 24 hours, showing a decreased risk with PGE2 (relative risk (RR) 0.61; 95% confidence interval (CI) 0.47 to 0.79). There was a small, and statistically non-significant, reduction of the risk of caesarean section when PGE2 was used (RR 0.88; 95% CI 0.77 to 1.00). The finding was statistically significant in a subgroup of women with intact membranes and unfavourable cervix only (RR 0.82; 95% CI 0.68 to 0.98). The risk of hyperstimulation with fetal heart rate (FHR) changes was not significantly increased (RR 1.21; 95% CI 0.72 to 2.05). However, the risk of hyperstimulation without FHR changes was significantly increased (RR 1.59; 95% CI 1.09 to 2.33. INTRACERVICAL PGE2 WITH INTRAVAGINAL PGE2: 29 TRIALS, 3881 WOMEN: The risk of not achieving vaginal delivery within 24 hours was increased with intracervical PGE2 (RR 1.26; 95% CI 1.12 to 1.41). There was no change in the risk of caesarean section (RR 1.07; 95% CI 0.93 to 1.22). The risks of hyperstimulation with FHR changes (RR 0.76; 95% CI 0.39 to 1.49) and without FHR changes (RR 0.80; 95% CI 0.56 to 1.15) were non-significantly different with the two methods of PGE2 administration. Only one trial with small sample size reported on women's views, with no difference between groups. INTRACERVICAL PGE2 LOW DOSE WITH INTRACERVICAL PGE2 HIGH DOSE: TWO TRIALS, 102 WOMEN: The trials are too small to provide any useful information.

AUTHORS' CONCLUSIONS

Intracervical prostaglandins are effective compared to placebo, but appear inferior when compared to intravaginal prostaglandins.

Continuity of nursing care and its link to cesarean birth rate

BACKGROUND

High cesarean birth rates are an international concern. The role of patterns of nursing care responsibility in preventing or contributing to cesarean births has been understudied. Our study sought to identify and describe indicators of continuity of nursing care responsibility during labor and to explore whether any association between these indicators and risk of cesarean birth could be identified empirically using an existing data set.

METHODS

We obtained a representative sample of low-risk women giving birth in an intrapartum unit at a university hospital in Quebec, Canada, with approximately 3,700 births per year. To be considered for inclusion, women needed to have been primiparous, carrying singletons in vertex position, and at 37 weeks' gestation or more. All women giving birth over a 13-month period were assessed for eligibility using the hospital's birth log. Data were extracted from the medical records of every second eligible birth, including information related to patterns of nursing care responsibility, maternal and infant characteristics, obstetric procedures, non-health-related risk factors, and type of birth.

RESULTS

Data on all variables of interest were available for 467 women. These women were cared for by 1-17 nurses, care responsibility changed hands for them from 1 to 28 times, and the mean length of labor for which the same nurse was responsible for a woman ranged from 10 to 1,045 minutes. After controlling for length of labor, maternal age, maternal height, infant weight, gestational age, induction, type of rupture, and epidural analgesia, the odds ratio for cesarean birth due to number of nurses was 1.17 (95% CI 1.04, 1.32); 1 or more nurses switch per 2 hours (i.e., number of times care responsibilities changed hands), 1.04 (95% CI 0.62, 1.74); and 33 percent or more of the labor attended by the same nurse, 0.74 (95% CI 0.42, 1.30).

CONCLUSIONS

An association was observed between number of nurses caring for a laboring woman and risk of cesarean delivery. Estimates of the association of other patterns of nursing care responsibility on cesarean birth were not sufficiently precise to draw conclusions.

Induction of labor at term using isosorbide mononitrate simultaneously with dinoprostone compared to dinoprostone treatment alone: a randomized, controlled trial

OBJECTIVE

We aimed to determine whether isosorbide mononitrate (IMN) given simultaneously with dinoprostone in term pregnancies is superior to dinoprostone alone to promote delivery.

STUDY DESIGN

One hundred and twenty nulliparous women at term were randomly assigned to receive per vaginam IMN 40 mg or placebo in addition to 3 mg dinoprostone 2 times daily for up to 2 days. Analysis was by intention to treat.

RESULTS

Baseline characteristics of both groups were comparable. The induction to delivery intervals did not differ between the IMN and the placebo group (26.4 +/- 14.4 vs 23.4 +/- 14.8 hours, P = .408). IMN resulted in more headache compared to placebo (32/55 [58.2%] vs 2/55 [3.6%], P < .001).

CONCLUSION

Vaginally administered IMN does not play a role in promoting delivery in term pregnancy if given at the same time as dinoprostone. This might reflect its relaxant effect on the uterine fundus, which may overcome its cervical softening effect.

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.

Oral misoprostol for induction of labour

BACKGROUND

Misoprostol is a synthetic prostaglandin that can be given orally or vaginally. In most countries misoprostol has not been licensed for use in pregnancy, but its unlicensed use is common because misoprostol is cheap, stable at room temperature and effective in causing uterine contractions. Oral use of misoprostol may be convenient, but high doses could cause uterine hyperstimulation and uterine rupture which may be life-threatening for both mother and fetus.

OBJECTIVES

To assess the effectiveness and safety of oral misoprostol used for labour induction in women with a viable fetus in the third trimester of pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (January 2005).

SELECTION CRITERIA

Randomised trials comparing oral misoprostol versus other methods, placebo or no treatment, given to women with a viable fetus for labour induction.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial quality and extracted data, using centrally-designed data sheets.

MAIN RESULTS

Forty-one trials (8606 participants) were included. In four trials comparing oral misoprostol with placebo (474 participants), women using oral misoprostol were less likely to have long labours (relative risk (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49), needed less oxytocin (RR 0.32, 95% CI 0.24 to 0.43) and had a lower caesarean section rate (RR 0.62, 95% CI 0.40 to 0.96). In nine trials comparing oral misoprostol with vaginal dinoprostone (2627 participants), women given oral misoprostol were less likely to need a caesarean section, but this reduction reached statistical significance only in the subgroup with intact membranes (RR 0.78, 95% CI 0.66 to 0.94). Uterine hyperstimulation was more common after oral misoprostol (RR 1.63, 95% CI 1.09 to 2.44) although this was not associated with any adverse fetal events. Seven trials (1017 participants) compared oral misoprostol with intravenous oxytocin. The only difference between the groups was an increase in meconium-stained liquor in women with ruptured membranes following administration of oral misoprostol (RR 1.72, 95% 1.08 to 2.74). Sixteen trials (3645 participants) compared oral and vaginal misoprostol and found no difference in the primary outcomes. There was less uterine hyperstimulation without fetal heart rate changes in those given oral misoprostol (RR 0.37, 95% 0.23 to 0.59). Oral misoprsotol was associated with increased need for oxytocin augmentation (RR 1.28, 95% 1.11 to 1.48) and more meconium-stained liquor (RR 1.27, 1.01 to 1.60).

AUTHORS' CONCLUSIONS

Oral misoprostol appears to be more effective than placebo and at least as effective as vaginal dinoprostone. However, there remain questions about its safety because of a relatively high rate of uterine hyperstimulation and the lack of appropriate dose ranging studies. In countries where misoprostol remains unlicenced for the induction of labour, many practitioners will prefer the legal protection of using a licenced product like dinoprostone. There is no evidence that misoprostol given orally is inferior to the vaginal route and has lower rates of hyperstimulation. If misoprostol is used orally, the dose should not exceed 50 mcg.

Planned early birth versus expectant management (waiting) for prelabour rupture of membranes at term (37 weeks or more)

BACKGROUND

Prelabour rupture of membranes at term is managed expectantly or by elective birth, but it is not clear if waiting for birth to occur spontaneously is better than intervening.

OBJECTIVES

To assess the effects of planned early birth versus expectant management for women with term prelabour rupture of membranes on fetal, infant and maternal wellbeing.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (November 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2004), MEDLINE (1966 to November 2004) and EMBASE (1974 to November 2004).

SELECTION CRITERIA

Randomised or quasi-randomised trials of planned early birth compared with expectant management in women with prelabour rupture of membranes at 37 weeks' gestation or more.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria, assessed trial quality and extracted data. A random-effects model was used.

MAIN RESULTS

Twelve trials (total of 6814 women) were included. Planned management was generally induction with oxytocin or prostaglandin, with one trial using homoeopathic caulophyllum. Overall, no differences were detected for mode of birth between planned and expectant groups: relative risk (RR) of caesarean section 0.94, 95% confidence interval (CI) 0.82 to 1.08 (12 trials, 6814 women); RR of operative vaginal birth 0.98, 95% 0.84 to 1.16 (7 trials, 5511 women). Significantly fewer women in the planned compared with expectant management groups had chorioamnionitis (RR 0.74, 95% CI 0.56 to 0.97; 9 trials, 6611 women) or endometritis (RR 0.30, 95% CI 0.12 to 0.74; 4 trials, 445 women). No difference was seen for neonatal infection (RR 0.83, 95% CI 0.61 to 1.12; 9 trials, 6406 infants). However, fewer infants under planned management went to neonatal intensive or special care compared with expectant management (RR 0.72, 95% CI 0.57 to 0.92, number needed to treat 20; 5 trials, 5679 infants). In a single trial, significantly more women with planned management viewed their care more positively than those expectantly managed (RR of "nothing liked" 0.45, 95% CI 0.37 to 0.54; 5031 women).

AUTHORS' CONCLUSIONS

Planned management (with methods such as oxytocin or prostaglandin) reduces the risk of some maternal infectious morbidity without increasing caesarean sections and operative vaginal births. Fewer infants went to neonatal intensive care under planned management although no differences were seen in neonatal infection rates. Since planned and expectant management may not be very different, women need to have appropriate information to make informed choices.

Macrophages and not granulocytes are involved in cervical ripening

To clarify the role of leucocytes in human cervical ripening and dilatation, cervical biopsies were obtained from six non-pregnant women, eight women undergoing early termination of pregnancy, 18 pregnant women undergoing elective Caesarean section at term (both with and without a ripe cervix as determined by Bishop score) and 11 women after term vaginal delivery. Leucocytes were localised by immunohistochemistry labelling and quantified in subepithelial and deep stromal areas. CD45+ leucocytes were more numerous in the subepithelial area of the cervix than in the deep stroma in all groups (P<0.01). CD14+ macrophages and CD15+ granulocytes were increased in both the subepithelial and deep stromal areas only in the vaginal delivery group (P<0.01). The number of macrophages in the ripening cervix (Bishop score above 4) was higher than in the unripe cervix (Bishop score 4 or less; P<0.05) with no differences in other leucocyte populations. CD3+ CD8+ T cells in the subepithelial area were reduced in late pregnancy and after vaginal delivery (P<0.01), but showed no relationship to Bishop score. Macrophages and granulocytes may be involved in the process of cervical dilatation, but macrophage infiltration into the ripening cervix before labour suggests their role in the ripening process. Reduced numbers of CD3+ CD8+ T-lymphocytes in late pregnancy and after vaginal delivery suggests that local immunity is down-regulated in the late pregnancy period. Regional differences in leucocyte subpopulations in the cervix indicate that leucocyte infiltration is likely to be regulated by local factors.

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.

Acupuncture for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. The use of complementary therapies is increasing and some women 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. The limited observational studies to date suggest acupuncture for induction of labour appears safe, has no known teratogenic effects, and may be effective. The evidence regarding the clinical effectiveness of this technique is limited.

OBJECTIVES

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

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (February 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003), PubMed (1966 to present), CISCOM (1960 to present), EMBASE (1980 to present) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing acupuncture 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

One trial of 56 women was included in the review. Data were not in a form that could be included in the meta-analysis.

REVIEWER'S CONCLUSIONS

There is a need for well-designed randomised controlled trials to evaluate the role of acupuncture to induce labour and for trials to assess clinically meaningful outcomes.

Induction of labour with a favourable cervix and/or pre-labour rupture of membranes

Premature rupture of membranes (PROM) occurs in 8% of term deliveries. In this situation labour induction with prostaglandins, compared with expectant management, results in a reduced risk of chorioamnionitis, neonatal antibiotic therapy, neonatal intensive care (NICU) admission, and increased maternal satisfaction. The use of prostaglandin is associated with an increased rate of diarrhoea and use of analgesia/anaesthesia. Compared with oxytocin, prostaglandin induction results in a lower rate of epidural use and internal fetal heart rate monitoring but a greater risk of chorioamnionitis, nausea, vomiting, more vaginal examinations, neonatal antibiotic therapy, NICU admission and neonatal infection. Women should be informed of the risks and benefits of each method of induction.Misoprostol is gaining increasing interest as an alternative induction agent. It appears to be an effective method of labour induction with term PROM. Further research is needed to identify the preferred dosage, route and interval of administration, and to assess uncommon maternal and neonatal outcomes. There has been limited research on the use of prostaglandins, including misoprostol, for induction of labour with a favourable cervix and intact membranes. Compared with intravenous oxytocin (with and without amniotomy), labour induction using vaginal prostaglandins in women with a favourable cervix (with and without PROM) results in a higher rate of vaginal delivery within 24 hours and increased maternal satisfaction. In women with a favourable cervix, artificial rupture of membranes followed by oral misoprostol has similar time to vaginal delivery compared with artificial rupture of membranes followed by oxytocin. Further research with prostaglandins, including misoprostol, is needed to evaluate other maternal and neonatal outcomes in women being induced with a favourable cervix. No form of prostaglandin induction in women with PROM or favourable cervix has proven clearly superior to oxytocin infusion.

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 STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000.

SELECTION CRITERIA

(1) 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; (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.

MAIN RESULTS

In the one included study of 100 women, which compared a single dose of castor oil versus no treatment, no difference was found between caesarean section rates (relative risk (RR) 2.31, 95% CI 0.77, 6.87). No data were presented on neonatal or maternal mortality or morbidity. There was no difference between either the rate of meconium stained liquor (RR 0.77, 95% CI 0.25,2.36) or Apgar score < 7 at 5 minutes (RR 0.92, 95% CI 0.02,45.71) between the two groups. The number of participants was small hence only large differences in outcomes could have been detected. All women who ingested castor oil felt nauseous.

REVIEWER'S CONCLUSIONS

The only trial included in this review attempts to address the role of castor oil as an induction agent. The trial was small and of poor methodological quality. Further research is needed to attempt to quantify the efficacy of castor oil as an induction agent.

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.

Amniotomy plus intravenous oxytocin for induction of labour

BACKGROUND

Induction of labour is a common obstetric intervention. Amniotomy alone for induction of labour is reviewed separately and oxytocin alone for induction of labour is being prepared for inclusion in The Cochrane Library. This review will address the use of the combination of these two methods for induction of labour in the third trimester. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine, from the best available evidence, the efficacy and safety of amniotomy and intravenous oxytocin for third trimester induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and reference lists of articles were searched. Date of last search: May 2001.

SELECTION CRITERIA

The criteria for inclusion included the following: (1) clinical trials comparing amniotomy plus intravenous oxytocin 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

Trial quality assessment and data extraction were done by both reviewers. 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 a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data is to be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman.

MAIN RESULTS

Seventeen trials involving 2566 women were included. Amniotomy and intravenous oxytocin were found to result in fewer women being undelivered vaginally at 24 hours than amniotomy alone (relative risk (RR) 0.03, 95% confidence intervals (CI) 0.001-0.49). This finding was based on the results of a single study of 100 women. As regards secondary results amniotomy and intravenous oxytocin resulted in significantly fewer instrumental vaginal deliveries than placebo (RR 0.18, CI 0.05-0.58). Amniotomy and intravenous oxytocin resulted in more postpartum haemorrhage than vaginal prostaglandins (RR 5.5, CI 1.26-24.07). Significantly more women were also dissatisfied with amniotomy and intravenous oxytocin when compared with vaginal prostaglandins, RR 53, CI 3.32-846.51.

REVIEWER'S CONCLUSIONS

Data on the effectiveness and safety of amniotomy and intravenous oxytocin are lacking. No recommendations for clinical practice can be made on the basis of this review. Amniotomy and intravenous oxytocin is a combination of two methods of induction of labour and both methods are utilised in clinical practice. If their use is to be continued it is important to compare the effectiveness and safety of these methods, and to define under which clinical circumstances one may be preferable to another.

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.