Oral misoprostol for induction of labour

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.

Reducing stillbirths: interventions during labour

BACKGROUND

Approximately one million stillbirths occur annually during labour; most of these stillbirths occur in low and middle-income countries and are associated with absent, inadequate, or delayed obstetric care. The low proportion of intrapartum stillbirths in high-income countries suggests that intrapartum stillbirths are largely preventable with quality intrapartum care, including prompt recognition and management of intrapartum complications. The evidence for impact of intrapartum interventions on stillbirth and perinatal mortality outcomes has not yet been systematically examined.

METHODS

We undertook a systematic review of the published literature, searching PubMed and the Cochrane Library, of trials and reviews (N = 230) that reported stillbirth or perinatal mortality outcomes for eight interventions delivered during labour. Where eligible randomised controlled trials had been published after the most recent Cochrane review on any given intervention, we incorporated these new trial findings into a new meta-analysis with the Cochrane included studies.

RESULTS

We found a paucity of studies reporting statistically significant evidence of impact on perinatal mortality, especially on stillbirths. Available evidence suggests that operative delivery, especially Caesarean section, contributes to decreased stillbirth rates. Induction of labour rather than expectant management in post-term pregnancies showed strong evidence of impact, though there was not enough evidence to suggest superior safety for the fetus of any given drug or drugs for induction of labour. Planned Caesarean section for term breech presentation has been shown in a large randomised trial to reduce stillbirths, but the feasibility and consequences of implementing this intervention routinely in low-/middle-income countries add caveats to recommending its use. Magnesium sulphate for pre-eclampsia and eclampsia is effective in preventing eclamptic seizures, but studies have not demonstrated impact on perinatal mortality. There was limited evidence of impact for maternal hyperoxygenation, and concerns remain about maternal safety. Transcervical amnioinfusion for meconium staining appears promising for low/middle income-country application according to the findings of many small studies, but a large randomised trial of the intervention had no significant impact on perinatal mortality, suggesting that further studies are needed.

CONCLUSION

Although the global appeal to prioritise access to emergency obstetric care, especially vacuum extraction and Caesarean section, rests largely on observational and population-based data, these interventions are clearly life-saving in many cases of fetal compromise. Safe, comprehensive essential and emergency obstetric care is particularly needed, and can make the greatest impact on stillbirth rates, in low-resource settings. Other advanced interventions such as amnioinfusion and hyperoxygenation may reduce perinatal mortality, but concerns about safety and effectiveness require further study before they can be routinely included in programs.

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.

Titrated low-dose vaginal and/or oral misoprostol to induce labour for prelabour membrane rupture: a randomised trial

OBJECTIVE

To evaluate the clinical effectiveness and safety of titrated low-dose misoprostol for induction of labour (IOL) in the presence of prelabour rupture of membranes (PROM).

DESIGN

Randomised controlled trial.

SETTING

Maternity units in the UK (9) and Egypt (1).

POPULATION

Women >34 weeks of gestation with PROM, singleton viable fetus and no previous caesarean section.

METHODS

Subjects randomised to IOL with a titrated low-dose misoprostol regimen (oral except if unfavourable cervix, where initial dose vaginal) or a standard induction method, namely vaginal dinoprostone followed by intravenous oxytocin if the cervix was unfavourable or intravenous oxytocin alone if the cervix was favourable.

MAIN OUTCOME MEASURES

Primary outcome measures were caesarean section and failure to achieve vaginal delivery within 24 hours. Analysis was by intention to treat.

RESULTS

The trial did not achieve the planned sample size of 1890 due to failure in obtaining external funding. Seven hundred and fifty-eight women were randomised (375 misoprostol and 383 standard). There were less caesarean section (14 versus 18%, relative risk [RR] 0.79; 95% CI 0.57-1.09) and less women who failed to achieve vaginal delivery within 24 hours in the misoprostol group (24 versus 31%, RR 0.79; 95% CI 0.63-1.00), but the differences were not statistically significant. Subgroup analysis showed that with unfavourable cervix, misoprostol may be more effective than vaginal dinoprostone. There was no difference in hyperstimulation syndrome. There were more maternal adverse effects with misoprostol, but no significant differences in maternal and neonatal complications.

CONCLUSIONS

Titrated low-dose misoprostol may be a reasonable alternative for IOL in the presence of PROM, particularly in women with an unfavourable cervix. Safety and rare serious adverse events could not be evaluated in a trial of this size.

A randomised controlled trial of intravaginal dinoprostone, intravaginal misoprostol and transcervical balloon catheter for labour induction

OBJECTIVE

To compare the efficacy and safety of induction of labour by vaginal application of dinoprostone or misoprostol or transcervical insertion of a balloon (Bard) catheter.

DESIGN

A non-blinded, randomised, controlled trial.

SETTING

A tertiary level Swedish hospital.

POPULATION

A total of 592 women who had undergone full-term pregnancies, not previously been subjected to a caesarean section, and required induction of labour for common, routine indications.

METHODS

Women were randomly assigned to induction of labour using intravaginal dinoprostone (2 mg once every 6 hours) or misoprostol (25 micrograms once every 4 hours) or a transcervical balloon catheter.

MAIN OUTCOME MEASURES

The time interval between induction to delivery in general and vaginal delivery in particular, the mode of delivery, maternal and neonatal parameters of outcome.

RESULTS

Of the 588 subjects included in the final intention-to-treat analysis, 191 were assigned to treatment with dinoprostone, 199 with misoprostol and 198 with the balloon catheter. The shortest mean induction-to-delivery interval was obtained with the catheter (12.9 hours versus 16.8 and 17.3 hours for dinoprostone and misoprostol, respectively). The efficacies of the two prostaglandins were similar. The maternal and neonatal outcomes associated with each of the three procedures were similar.

CONCLUSIONS

Induction of labour with a transcervical balloon catheter is effective and safe and can be recommended as the first choice. The two prostaglandins, dinoprostone and misoprostol, were shown to be equally effective and safe, while misoprostol costs significantly less and is easier to store.

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.

Does postoperative misoprostol use induce intestinal motility? A prospective randomised double-blind trial

BACKGROUND

Misoprostol has been shown to increase colonic activity and decrease colonic transit time in chronic constipation patients.

AIMS

The aim of this prospective, randomised, double-blind study was to examine the effectiveness of rectally administered misoprostol on inducing intestinal motility after gynaecological surgery.

METHODS

Eighty women who underwent hysterectomy were divided randomly into three groups. Group A received misoprostol 200 microg rectally while group B received 400 microg rectal misoprostol after surgery before leaving the operating room. Patients in group C received no drugs. Bowel sounds in four quadrants were checked every hour and possible side-effects of misoprostol like nausea, vomiting, and distension were evaluated. The time interval between surgery and flatus pass and the need of analgesics were noted. Statistical analyses were done with Mann-Whitney U-test and chi2 tests where available.

RESULTS

The time between surgery and presence of bowel sounds in four quadrants were similar in all groups (2.7 +/- 1.6, 2.9 +/- 1.2, 2.8 +/- 1.3 h, for groups A, B, and C, respectively). No difference was observed in flatus pass time. The incidence of nausea was significantly increased in group B compared to controls (P < 0.01). Additional analgesic need was significantly higher in groups A and B when compared to controls (P < 0.05 and P < 0.01, for groups A and B, respectively).

CONCLUSION

Rectally administered misoprostol does not improve intestinal motility in the early postoperative period and thus, it is not effective in providing early oral food intake. On the contrary, it causes distention that requires additional analgesics and vomiting that naturally limits oral diet intake.

A randomised comparison of patient satisfaction with vaginal and sublingual misoprostol for induction of labour at term*

OBJECTIVE

To compare patient satisfaction with two routes of misoprostol for term labour induction.

DESIGN

Prospective randomised trial.

SETTING

Tertiary care hospital.

POPULATION

A total of 170 women admitted at > or = 37 weeks of gestation for induction of labour.

METHODS

Women were randomised to receive 50 micrograms of either sublingual or vaginal misoprostol.

MAIN OUTCOME MEASURES

Patient satisfaction with the route of administration.

RESULTS

Despite a similar proportion reporting the labour induction as more painful than expected in both groups, a significantly lower proportion mentioned that the pelvic examinations were very painful in the sublingual group (19.7 versus 36.1%, relative risk [RR] 0.5, 95% CI 0.3-0.9). Request for analgesia was similar in both groups. More women in the sublingual group thought that the labour experience was better than expected (RR 2.0, 95% CI 1.2-3.3), had a positive attitude towards induction in subsequent pregnancies (RR 1.6, 95% CI 1.1-2.3) and preferred the same route in subsequent pregnancies (RR 3.1, 95% CI 2.2-4.5). Mean number of misoprostol doses, oxytocin augmentation, tachysystole and hyperstimulation, induction to vaginal delivery interval, vaginal delivery after a single dose, vaginal birth within 12 and 24 hours, and caesarean delivery rates were similar in both groups.

CONCLUSION

Sublingual misoprostol (50 micrograms) is associated with a significantly higher patient satisfaction rate compared with a similar dose of vaginal misoprostol. Sublingual administration offers additional choice to women, in particular those wishing to avoid vaginal administration.

Rectal Misoprostol Versus Oxytocin in the Management of the Third Stage of Labour

OBJECTIVE

To compare the effect of rectal misoprostol with intramuscular oxytocin in the routine management of the third stage in a rural developing country.

METHODS

A randomized controlled trial was performed at two district hospitals in Ghana, West Africa. Four hundred fifty women in advanced labour were enrolled. The only exclusion criterion was a known medical contraindication to prostaglandin administration. Women were randomized to receive rectal misoprostol 800 microg or intramuscular oxytocin 10 IU with delivery of the anterior shoulder. The main outcome measure was change in hemoglobin concentration from before to after delivery. Secondary outcomes included the need for additional uterotonics, estimated blood loss, transfusion, and medication side effects.

RESULTS

Demographic characteristics were similar in each treatment group. There was no significant difference between treatment groups in change in hemoglobin (misoprostol 1.19 g/dL and oxytocin 1.16 g/dL; relative difference 2.6%; 95% confidence intervals [CI]-16.8% to 19.4%; P = 0.80). The only significant secondary outcome was shivering, which was more common in the misoprostol group (misoprostol 7.5% vs. oxytocin 0.9%; relative risk 8.0; 95% CI 1.86-34.36; P = 0.001).

CONCLUSION

Rectal misoprostol 800 microg is as effective as 10 IU intramuscular oxytocin in minimizing blood loss in the third stage of labour. Rectal misoprostol has a lower incidence of side effects than the equivalent oral dose. This confirms the utility of misoprostol as a safe and effective uterotonic for use in the rural and remote areas of developing nations where other pharmacologic agents may be less feasible.

A Randomized Trial of Oral Misoprostol in Premenopausal Women Before Hysteroscopy

OBJECTIVE

To determine if the use of oral misoprostol in premenopausal women undergoing diagnostic hysteroscopy produces a clinically important difference in pre-procedural cervical dilatation.

METHODS

At a tertiary care hospital, premenopausal women undergoing diagnostic hysteroscopy were randomized to receive either 400 microg of misoprostol or a vitamin B6 placebo orally 12 hours before the procedure. Patients were stratified on the basis of parity. The primary outcome was the pre-procedural dilatation of the cervix. Secondary outcomes included the need to further dilate the cervix, the time required to further dilate the cervix, and side effects.

RESULTS

Sixty-four women (11 nulliparous and 53 parous) undergoing diagnostic hysteroscopy consented to participate in the study. Thirty-three women received misoprostol and 31 received placebo. Baseline demographics showed no difference in age and parity between the two groups. There were no significant differences in pre-procedural dilatation (5.0 mm vs. 4.7 mm, P = 0.52), need to further dilate the cervix (56.7% vs. 63.0%, P = 0.63), and time required to further dilate the cervix (12.7 seconds vs. 25.7 seconds, P = 0.27). Significantly more women in the misoprostol group experienced menstrual-like cramping (24.2% vs. 3.3%, P = 0.03) and vaginal spotting (21.2% vs. 3.3%, P = 0.05).

CONCLUSION

In premenopausal women, there is no improvement in pre-procedural cervical dilatation with administration of oral misoprostol 12 hours before diagnostic hysteroscopy. Further research is required in both nulliparous and parous premenopausal women to determine whether oral misoprostol improves cervical dilatation and, if so, the ideal dose, route and timing.

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.

Misoprostol versus cervagem for the induction of labour to terminate pregnancy in the second and third trimester: A systematic review

AIMS

to compare the benefits and harms of misoprostol to induce labour in the second and third trimester of pregnancy with cervagem.

METHODS

MEDLINE was searched using the terms abortion, induced; abortifacient agents; pregnancy, second trimester; pregnancy, third trimester; misoprostol; cervagem; and gemeprost to identify randomised controlled trials in which misoprostol was compared with cervagem, for induction of labour to terminate pregnancy in the second or third trimester. Outcomes included vaginal birth not achieved within 24h; induction to delivery interval; analgesia requirements; blood loss; blood transfusion; surgical evacuation of the uterus; maternal death or serious maternal morbidity; side effects.

RESULTS

Six randomised trials were included. Five compared vaginal misoprostol with cervagem [el Refaey H, Hinshaw K, Templeton A. The abortifacient effect of misoprostol in the second trimester: a randomized comparison with gemeprost in patients pre-treated with mifepristone (RU486). Hum Reprod 1993;8(10):1744-6; Ho PC, Chan YF, Lau W. Misoprostol is as effective as gemeprost in termination of second trimester pregnancy when combined with mifepristone: a randomised comparative trial. Contraception 1996;53(5):281-3; Nuutila M, Toivonen J, Ylikorkala O, Halmesmaki E. A comparison between two doses of intravaginal misoprostol and gemeprost for induction of second trimester abortion. Obstetr Gynecol 1997;90(6):896-900; Wong KS, Ngai CS, Wong AY, Tang LC, Ho PC. Vaginal misoprostol compared with vaginal gemeprost in termination of pregnancy: a randomized controlled trial. Contraception 1998;58(4):207-10; Dickinson JE, Godfrey M, Evans SF. Efficacy of intravaginal misoprostol in second trimester termination of pregnancy: a randomized controlled trial. J Mater Fetal Med 1999;7(3):115-9], and one oral misoprostol with gemeprost [Bartley J, Baird DT. A randomised study of misoprostol and gemeprost in combination with mifepristone for induction of abortion in the second trimester of pregnancy. Br J Obstetr Gynaecol 2002;109(11):1290-4]. Vaginal misoprostol compared with cervagem was associated with reduced narcotic analgesia (3 studies, 169 women, RR 0.64 95% CI 0.49-0.84), and surgical evacuation of the uterus (5 studies, 319 women, RR 0.71 95% CI 0.53-0.95). No other statistically significant differences were observed for other outcomes with reported data. In the single trial comparing oral misoprostol with gemeprost, reported outcomes were similar.

CONCLUSIONS

Vaginal misoprostol for the termination of second and third trimester of pregnancy appears as effective as cervagem, but information about maternal safety is limited.

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.

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.

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.