Effect of membrane sweeping at term pregnancy on duration of pregnancy and labor induction: a randomized trial

Effectiveness of Single Fetal Membrane Sweeping in Reducing Elective Labor Induction for Postdate Pregnancies (38+0 to 40+6 Weeks): A Randomized Controlled Trial

BACKGROUND

 Postdate pregnancy is characterized by a heightened risk for both maternal and perinatal complications. Owing to the risks, clinicians frequently turn to elective labor induction as a management strategy for postdate pregnancies. However, patients are increasingly informed and apprehensive about this approach and its associated risks. This has prompted a search for alternative management methods that may encourage spontaneous labor in pregnant women. One such approach is the use of fetal membrane sweeping, a method known to increase the likelihood of spontaneous labor onset. Yet, it remains unclear whether a single fetal membrane sweeping procedure can effectively reduce the need for elective labor induction in postdate pregnancies while minimizing risks to both the mother and fetus.

OBJECTIVES

The primary objective of this study was to assess the efficacy of a single fetal membrane sweeping procedure conducted between 38+0 and 40+6 weeks of gestation in reducing the rate of elective labor induction among postdate pregnancies at Central Hospital Benin City, Nigeria. Secondary objectives included evaluating the impact of membrane sweeping on maternal and perinatal outcomes.

METHODOLOGY

This open-label superiority randomized controlled study was carried out from June 2020 to March 2021, following ethical approval from the Hospital Management Board (HMB). One hundred and forty eligible participants, without contraindications to vaginal delivery, were randomly assigned to one of two groups. The first group received a single fetal membrane sweeping procedure between 38+0 and 40+6 weeks of gestation, while the control group underwent vaginal examination only to assess the Bishop score. Participants were monitored until delivery. Data analysis was performed. Results were considered statistically significant at p < 0.05.

RESULTS

The implementation of a single fetal membrane sweeping procedure effectively reduced the incidence of elective labor induction. Specifically, the membrane sweep group exhibited a significantly lower rate of elective labor induction compared to the control group (9.0% vs. 27.1%; p=0.0083). Moreover, a substantial proportion of the treatment group (91.4%) experienced spontaneous labor, while the control group reported a rate of 72.9%. The difference was statistically significant (p=0.0054). Notably, the control group exhibited a significantly longer mean time interval from recruitment to delivery (10.67±3.51 days) than the membrane sweeping group (3.64±4.123 days; p<0.05). Also, postdate women in the membrane sweep group were less likely to require cervical ripening with Foley's catheter than those in the control group (33.3% vs. 100%; RR: 0.33 (0.11-1.03); p=0.0057). Still, maternal satisfaction was significantly higher in the membrane-sweeping group (p<0.01). No significant differences were noted across the groups in maternal and neonatal outcomes.

CONCLUSION

In low-risk term pregnancies, a single fetal membrane sweeping procedure is a superior alternative to no membrane sweeping in reducing the rate of elective labor induction for postdate pregnancies and in shortening the duration of term pregnancy.

Perinatal and maternal outcomes according to timing of induction of labour: A systematic review and meta-analysis

The risk of adverse perinatal and maternal outcomes increases with gestational age, and although induction of labour may reduce these risks, the optimal timing of induction remains unknown. We carried out a systematic review and meta-analysis, to determine the gestational age at which induction should be offered. We searched Cochrane Central Register of Controlled Trials, Medline, and Embase databases from inception to July 2022, to identify randomised trials comparing induction of labour at or beyond 37' weeks gestation with expectant management or delayed induction, and according to the gestational age at planned induction. We undertook random effects meta-analysis and pooled estimates as odds ratios with 95% confidence intervals. We assessed risk of bias of studies using the Cochrane Risk of Bias tool 2.0. We included 44 trials (23,960 women and 22,191 offspring) from 1,839 citations in our meta-analysis. The odds of perinatal death (odds ratio 0.42, 95% confidence interval 0.22 to 0.81; 26 studies, 20,154 offspring), stillbirth (0.40, 0.16 to 0.98; 25 studies, 19,412 offspring), admission to neonatal intensive care unit (0.86, 0.78 to 0.96; 23 studies, 18,846 offspring), and caesarean section (0.90, 0.83 to 0.98; 40 studies, 23,616 women) were reduced in the induction of labour group compared to expectant management or delayed induction. The odds of admission to neonatal intensive care unit (0.82, 0.70 to 0.96; 6 studies, 9,316 offspring) were lower with induction of labour at 41 weeks compared to induction at or after 42 weeks' gestation, and the odds of caesarean section were reduced with labour induction at 39 weeks' compared to induction at or after 40 weeks' (0.83, 0.74 to 0.93; 8 studies, 7,677 women). There were no significant differences in pregnancy outcomes by method of induction of labour. Induction of labour compared to expectant management or delayed induction reduces the risk of adverse pregnancy outcomes, and the optimal timing may depend on the specific outcome of interest.

Membrane Stripping Method’s Effect On Pregnancy Period For Term Pregnants

Amaç: Doğum indüksiyon metodlarından membran sweeping veya stripping yöntemi obstetrikte miadında gebelerde sık kullanılan işlemlerden biridir, non-farmakolojik yöntemlerdendir. Çalışmada bu yöntemin doğum sürecindeki etkileri, doğumu başlatma ve gebelik süresini kısaltma, postterm gebeliği önleme, indüksiyon gereksinimini azaltma yönlerinden etkinliği, etkinliğine etki eden faktörleri ve bu yönteme bağlı fetal ve maternal sonuçları araştırmak hedeflendi. Gereç ve Yöntemler: Çalışmaya, ilk obstetrik değerlendirmede tekil canlı gebeliği olan, 38-40 hafta arası miadında olan, sezaryen veya herhangi bir uterin cerrahi geçirmemiş olan, Bishop skoru 4 veya daha küçük olan, vajinal yoldan doğum için kontrendikasyonu olmayan olgular alındı. Çalışma toplam 213 olgu üzerinde yapıldı. 108 olgu (42 multipar, 66 nullipar) çalışma, 105 olgu (48 multipar, 57 nullipar) kontrol grubunu oluşturdu. Bulgular: Çalışma grubunda uygulamadan doğuma kadar geçen süre ortalaması 7,04 ± 3,96, kontrol grubunda ise 9,24 ± 5,01 bulundu. Çalışma grubunda 7 gün içerisinde vajinal doğum yapma oranı (%68,5), kontrol grubundan (%43,8) istatistiksel olarak ileri düzeyde anlamlı yüksek bulundu. Çalışma grubunda 41. Gebelik haftasından önce doğum yapma oranı (%84,3), kontrol grubundan (%69,5) istatistiksel olarak anlamlı düzeyde yüksek bulundu. İndüksiyon gereksinimi çalışma grubunda (%11,1) kontrol grubuna (%23,8) kıyasla istatistiki olarak anlamlı düzeyde düşük bulunmuştur. Her iki grup doğum şekli, erken membran rüptürü, neonatal sonuçlar, maternal enfeksiyon açısından karşılaştırıldıklarında sonuçlar benzer bulundu. Sonuç: Membran sıyırma yönteminin, komplike olmayan 38-40 hafta arasındaki term gebelerde, maternal-fetal sonuçları değiştirmeden, uygulamadan doğuma kadar geçen süreyi, postterm gebelik oranlarını ve indüksiyon gereksinimini azaltma açısından etkili ve güvenilir bir yöntem olduğu gözlemlenmiştir.

Membrane sweeping for induction of labour

BACKGROUND

Induction of labour involves stimulating uterine contractions artificially to promote the onset of labour. There are several pharmacological, surgical and mechanical methods used to induce labour. Membrane sweeping is a mechanical technique whereby a clinician inserts one or two fingers into the cervix and using a continuous circular sweeping motion detaches the inferior pole of the membranes from the lower uterine segment. This produces hormones that encourage effacement and dilatation potentially promoting labour. This review is an update to a review first published in 2005.

OBJECTIVES

To assess the effects and safety of membrane sweeping for induction of labour in women at or near term (≥ 36 weeks' gestation).

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (25 February 2019), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (25 February 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing membrane sweeping used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed on a predefined list of labour induction methods. Cluster-randomised trials were eligible, but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, risk of bias and extracted data. Data were checked for accuracy. Disagreements were resolved by discussion, or by including a third review author. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 44 studies (20 new to this update), reporting data for 6940 women and their infants. We used random-effects throughout. Overall, the risk of bias was assessed as low or unclear risk in most domains across studies. Evidence certainty, assessed using GRADE, was found to be generally low, mainly due to study design, inconsistency and imprecision. Six studies (n = 1284) compared membrane sweeping with more than one intervention and were thus included in more than one comparison. No trials reported on the outcomes uterine hyperstimulation with/without fetal heart rate (FHR) change, uterine rupture or neonatal encephalopathy. Forty studies (6548 participants) compared membrane sweeping with no treatment/sham Women randomised to membrane sweeping may be more likely to experience: · spontaneous onset of labour (average risk ratio (aRR) 1.21, 95% confidence interval (CI) 1.08 to 1.34, 17 studies, 3170 participants, low-certainty evidence). but less likely to experience: · induction (aRR 0.73, 95% CI 0.56 to 0.94, 16 studies, 3224 participants, low-certainty evidence); There may be little to no difference between groups for: · caesareans (aRR 0.94, 95% CI 0.85 to 1.04, 32 studies, 5499 participants, moderate-certainty evidence); · spontaneous vaginal birth (aRR 1.03, 95% CI 0.99 to 1.07, 26 studies, 4538 participants, moderate-certainty evidence); · maternal death or serious morbidity (aRR 0.83, 95% CI 0.57 to 1.20, 17 studies, 2749 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.83, 95% CI 0.59 to 1.17, 18 studies, 3696 participants, low-certainty evidence). Four studies reported data for 480 women comparing membrane sweeping with vaginal/intracervical prostaglandins There may be little to no difference between groups for the outcomes: · spontaneous onset of labour (aRR, 1.24, 95% CI 0.98 to 1.57, 3 studies, 339 participants, low-certainty evidence); · induction (aRR 0.90, 95% CI 0.56 to 1.45, 2 studies, 157 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.44 to 1.09, 3 studies, 339 participants, low-certainty evidence); · spontaneous vaginal birth (aRR 1.12, 95% CI 0.95 to 1.32, 2 studies, 252 participants, low-certainty evidence); · maternal death or serious morbidity (aRR 0.93, 95% CI 0.27 to 3.21, 1 study, 87 participants, low-certainty evidence); · neonatal perinatal death or serious morbidity (aRR 0.40, 95% CI 0.12 to 1.33, 2 studies, 269 participants, low-certainty evidence). One study, reported data for 104 women, comparing membrane sweeping with intravenous oxytocin +/- amniotomy There may be little to no difference between groups for: · spontaneous onset of labour (aRR 1.32, 95% CI 88 to 1.96, 1 study, 69 participants, low-certainty evidence); · induction (aRR 0.51, 95% CI 0.05 to 5.42, 1 study, 69 participants, low-certainty evidence); · caesarean (aRR 0.69, 95% CI 0.12 to 3.85, 1 study, 69 participants, low-certainty evidence); · maternal death or serious morbidity was reported on, but there were no events. Two studies providing data for 160 women compared membrane sweeping with vaginal/oral misoprostol There may be little to no difference between groups for: · caesareans (RR 0.82, 95% CI 0.31 to 2.17, 1 study, 96 participants, low-certainty evidence). One study providing data for 355 women which compared once weekly membrane sweep with twice-weekly membrane sweep and a sham procedure There may be little to no difference between groups for: · induction (RR 1.19, 95% CI 0.76 to 1.85, 1 study, 234 participants, low-certainty); · caesareans (RR 0.93, 95% CI 0.60 to 1.46, 1 study, 234 participants, low-certainty evidence); · spontaneous vaginal birth (RR 1.00, 95% CI 0.86 to 1.17, 1 study, 234 participants, moderate-certainty evidence); · maternal death or serious maternal morbidity (RR 0.78, 95% CI 0.30 to 2.02, 1 study, 234 participants, low-certainty evidence); · neonatal death or serious neonatal perinatal morbidity (RR 2.00, 95% CI 0.18 to 21.76, 1 study, 234 participants, low-certainty evidence); We found no studies that compared membrane sweeping with amniotomy only or mechanical methods. Three studies, providing data for 675 women, reported that women indicated favourably on their experience of membrane sweeping with one study reporting that 88% (n = 312) of women questioned in the postnatal period would choose membrane sweeping in the next pregnancy. Two studies reporting data for 290 women reported that membrane sweeping is more cost-effective than using prostaglandins, although more research should be undertaken in this area.

AUTHORS' CONCLUSIONS

Membrane sweeping may be effective in achieving a spontaneous onset of labour, but the evidence for this was of low certainty. When compared to expectant management, it potentially reduces the incidence of formal induction of labour. Questions remain as to whether there is an optimal number of membrane sweeps and timings and gestation of these to facilitate induction of labour.

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

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

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

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

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

Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour.

OBJECTIVE

To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups.

METHODS

We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group's Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012-13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves.

RESULTS

We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed 'best'. Few studies collected information on women's views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective.

LIMITATIONS

There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses.

CONCLUSIONS

Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention.

FUTURE WORK

Future trials should be powered to detect a method that is more cost-effective than misoprostol solution and report outcomes included in this NMA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Use of labour induction and risk of cesarean delivery: a systematic review and meta-analysis

BACKGROUND

Induction of labour is common, and cesarean delivery is regarded as its major complication. We conducted a systematic review and meta-analysis to investigate whether the risk of cesarean delivery is higher or lower following labour induction compared with expectant management.

METHODS

We searched 6 electronic databases for relevant articles published through April 2012 to identify randomized controlled trials (RCTs) in which labour induction was compared with placebo or expectant management among women with a viable singleton pregnancy. We assessed risk of bias and obtained data on rates of cesarean delivery. We used regression analysis techniques to explore the effect of patient characteristics, induction methods and study quality on risk of cesarean delivery.

RESULTS

We identified 157 eligible RCTs (n = 31,085). Overall, the risk of cesarean delivery was 12% lower with labour induction than with expectant management (pooled relative risk [RR] 0.88, 95% confidence interval [CI] 0.84-0.93; I(2) = 0%). The effect was significant in term and post-term gestations but not in preterm gestations. Meta-regression analysis showed that initial cervical score, indication for induction and method of induction did not alter the main result. There was a reduced risk of fetal death (RR 0.50, 95% CI 0.25-0.99; I(2) = 0%) and admission to a neonatal intensive care unit (RR 0.86, 95% CI 0.79-0.94), and no impact on maternal death (RR 1.00, 95% CI 0.10-9.57; I(2) = 0%) with labour induction.

INTERPRETATION

The risk of cesarean delivery was lower among women whose labour was induced than among those managed expectantly in term and post-term gestations. There were benefits for the fetus and no increased risk of maternal death.

Methods of induction of labour: a systematic review

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Membrane sweeping to induce labor in low-risk patients at term pregnancy: a randomised controlled trial

OBJECTIVE

To evaluate the efficacy of membrane sweeping at initiation of labor induction in low-risk patients at term pregnancy (38-40 gestational weeks).

METHODS

This prospective study included 351 antenatal women who were randomly assigned to one of two groups: a sweeping of the membranes group (n = 181) and a no sweeping control group (n = 170). The primary outcome measure was the proportion of women who entered spontaneous labor within 1 week of entry into the study. Secondary outcome measures included mode of delivery and maternal and fetal complications.

RESULTS

Five patients (two in the sweeping group and three in the no sweeping group) were excluded from the study because of breech presentation at labor. There were no statistically significant differences between the two groups regarding maternal age, parity or Bishop score. The proportion of subjects who entered spontaneous labor before 41 weeks of gestation was significantly different between the two groups (p < 0.0001). The mode of delivery did not differ significantly between the groups and there was no statistically significant difference in maternal or fetal complications.

CONCLUSIONS

Sweeping of membranes is a safe method to reduce the length of term in pregnancy and the incidence of prolonged gestation in a low-risk population. There is no evidence that sweeping the membranes increases the risk of maternal or neonatal adverse outcomes.

Postterm pregnancy: how can we improve outcomes?

Postterm pregnancy is defined as one which has progressed to 42 0/7 weeks or beyond. The most common reason to be diagnosed with a postterm pregnancy is inaccurate pregnancy dating, but it is also associated with obesity, nulliparity, and a prior history of postterm pregnancy. The rate of postterm pregnancy appears to be decreasing whether due to improved pregnancy dating or an increase in induction of labor. Postterm pregnancy is associated with both maternal and neonatal morbidity and fetal and neonatal mortality; similarly pregnancies beyond 41 weeks' gestation are associated with increases in these perinatal complications. Prevention of postterm pregnancies may include stripping or sweeping the membranes and unprotected coitus. Management of such pregnancies may include induction of labor and fetal antenatal monitoring. Individual patient management should involve careful counseling regarding the risks and benefits of each of the components of care.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall the increasing risks of poor outcomes associated with prolonged pregnancy, demonstrate knowledge regarding gestational dating and use of cervical ripening agents in their care of pregnant women, and use evidence-based information when counseling their term patients regarding postterm pregnancy management.

Membrane sweeping for induction of labour

BACKGROUND

Sweeping of the membranes, also named stripping of the membranes, is a relatively simple technique usually performed without admission to hospital. During vaginal examination, the clinician's finger is introduced into the cervical os. Then, the inferior pole of the membranes is detached from the lower uterine segment by a circular movement of the examining finger. This intervention has the potential to initiate labour by increasing local production of prostaglandins and, thus, reduce pregnancy duration or pre-empt formal induction of labour with either oxytocin, prostaglandins or amniotomy. 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 membrane sweeping for third trimester induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (6 July 2004) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing membrane sweeping 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

Twenty-two trials (2797 women) were included, 20 comparing sweeping of membranes with no treatment, three comparing sweeping with prostaglandins and one comparing sweeping with oxytocin (two studies reported more than one comparison). Risk of caesarean section was similar between groups (relative risk (RR) 0.90, 95% confidence interval (CI) 0.70 to 1.15). Sweeping of the membranes, performed as a general policy in women at term, was associated with reduced duration of pregnancy and reduced frequency of pregnancy continuing beyond 41 weeks (RR 0.59, 95% CI 0.46 to 0.74) and 42 weeks (RR 0.28, 95% CI 0.15 to 0.50). To avoid one formal induction of labour, sweeping of membranes must be performed in eight women (NNT = 8). There was no evidence of a difference in the risk of maternal or neonatal infection. Discomfort during vaginal examination and other adverse effects (bleeding, irregular contractions) were more frequently reported by women allocated to sweeping. Studies comparing sweeping with prostaglandin administration are of limited sample size and do not provide evidence of benefit.

AUTHORS' CONCLUSIONS

Routine use of sweeping of membranes from 38 weeks of pregnancy onwards does not seem to produce clinically important benefits. When used as a means for induction of labour, the reduction in the use of more formal methods of induction needs to be balanced against women's discomfort and other adverse effects.