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.
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.
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.
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.
AbstractObjectiveTo evaluate if induction of labour at 41 weeks improves perinatal and maternal outcomes in women with a low risk pregnancy compared with expectant management and induction of labour ...at 42 weeks.DesignMulticentre, open label, randomised controlled superiority trial.Setting14 hospitals in Sweden, 2016-18.Participants2760 women with a low risk uncomplicated singleton pregnancy randomised (1:1) by the Swedish Pregnancy Register. 1381 women were assigned to the induction group and 1379 were assigned to the expectant management group.InterventionsInduction of labour at 41 weeks and expectant management and induction of labour at 42 weeks.Main outcome measuresThe primary outcome was a composite perinatal outcome including one or more of stillbirth, neonatal mortality, Apgar score less than 7 at five minutes, pH less than 7.00 or metabolic acidosis (pH <7.05 and base deficit >12 mmol/L) in the umbilical artery, hypoxic ischaemic encephalopathy, intracranial haemorrhage, convulsions, meconium aspiration syndrome, mechanical ventilation within 72 hours, or obstetric brachial plexus injury. Primary analysis was by intention to treat.ResultsThe study was stopped early owing to a significantly higher rate of perinatal mortality in the expectant management group. The composite primary perinatal outcome did not differ between the groups: 2.4% (33/1381) in the induction group and 2.2% (31/1379) in the expectant management group (relative risk 1.06, 95% confidence interval 0.65 to 1.73; P=0.90). No perinatal deaths occurred in the induction group but six (five stillbirths and one early neonatal death) occurred in the expectant management group (P=0.03). The proportion of caesarean delivery, instrumental vaginal delivery, or any major maternal morbidity did not differ between the groups.ConclusionsThis study comparing induction of labour at 41 weeks with expectant management and induction at 42 weeks does not show any significant difference in the primary composite adverse perinatal outcome. However, a reduction of the secondary outcome perinatal mortality is observed without increasing adverse maternal outcomes. Although these results should be interpreted cautiously, induction of labour ought to be offered to women no later than at 41 weeks and could be one (of few) interventions that reduces the rate of stillbirths.Trial registrationCurrent Controlled Trials ISRCTN26113652.
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BFBNIB, CMK, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Background
It has been suggested that cervical ripening with a balloon catheter for labour induction can be done in an outpatient setting in low‐risk pregnancies. Introduction of such an approach ...needs to be accompanied with monitoring of potential complications. Therefore the existence and frequency of any associated adverse event during cervical ripening needs to be established.
Objective
To assess the complication rate during cervical ripening with balloon induction.
Search strategy
We searched Embase, Medline, Cochrane Collaboration and CINAHL using keywords ‘induction of labour’, ‘cervical ripening’, ‘balloon catheter’, ‘Foley balloon’, ‘transcervical balloon’.
Selection criteria
We included randomized controlled trials and cohort studies containing original data on fetal and maternal morbidity in pregnant women during cervical ripening with a balloon catheter. Only articles for which authors were able to give data for this exact time frame were included.
Data collection and analysis
Two reviewers assessed independently the eligibility of included studies, extracted data and performed a quality assessment. A meta‐analysis was performed to calculate the estimated prevalence of the adverse events.
Main results
In total 26 studies were included reporting on 8292 women. The estimated prevalence of the analysed adverse events in the random effects model was between 0.0 and 0.26%, of which ‘pain/discomfort’ had the highest prevalence.
Conclusion
This study suggests the risk of adverse events during the period between insertion and expulsion of a balloon catheter in cervical ripening to be low. These data facilitate further evaluation and implementation of this procedure in an outpatient setting for low‐risk pregnancies.
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Balloon catheter for cervical ripening appears to be safe enough to evaluate its use in the outpatient setting.
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Balloon catheter for cervical ripening appears to be safe enough to evaluate its use in the outpatient setting.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
OBJECTIVE:To test the hypothesis that digital placement of a balloon catheter is not inferior to the speculum method in terms of rate of maternal infection.
METHODS:In an open-label noninferiority ...randomized trial, pregnant women who were undergoing induction of labor with unfavorable cervix (less than 3 cm dilated and less than 60% effaced) were randomly assigned to balloon catheter that was placed either digitally or using a sterile speculum. The primary outcome was a composite of maternal infection, defined by occurrence of fever (temperature 38°C or higher), chorioamnionitis, or endometritis (diagnoses were made by the managing obstetric physician or midwife). Prespecified secondary outcomes included outcomes in the primary composite, cesarean delivery rates, and maternal and neonatal outcomes. A patient satisfaction survey was also obtained. On the basis of a noninferiority margin of 10% and an expected primary outcome frequency of 10%, a sample size of 372 women was needed (90% power to confirm noninferiority with 90% protocol adherence).
RESULTS:From February 2018 through February 2019, 372 women were randomized (185 digital placement, 187 sterile speculum). Baseline characteristics were similar between groups. The composite maternal infection rate was not different between groups (digital placement arm15.7% vs speculum arm12.8%), with an absolute difference with respect to the sterile speculum arm of 2.8% (95% CI −4.3 to 9.9%), indicating noninferiority for the prespecified margin. Secondary outcomes were not different between groups, except for a higher need for a second balloon catheter in the sterile speculum arm. Maternal and neonatal adverse events were not different between groups. Irrespective of method of placement, women were equally satisfied with the explanation of the method before placement, anxiety regarding the procedure, and pain during placement. More women in the sterile speculum group would choose the digital placement method for the subsequent pregnancy (37.6% vs 25.7%; P=.02.)
CONCLUSION:Digital placement of a balloon catheter for preinduction cervical ripening is noninferior to the sterile speculum method, in terms of maternal infection. Women in the sterile speculum group more frequently required a second round of the mechanical dilator. The blind digital approach is a reasonable option for balloon placement for cervical ripening.
CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT03450408.
To assess the comparative effectiveness and potential harms of cervical ripening in the outpatient compared with the inpatient setting, or different methods of ripening in the outpatient setting ...alone.
Searches for articles in English included MEDLINE, EMBASE, CINAHL, Cochrane Library, ClinicalTrials.gov, and reference lists (up to August 2020).
Using predefined criteria and DistillerSR software, 10,853 citations were dual-reviewed for randomized controlled trials (RCTs) and cohort studies of outpatient cervical ripening using prostaglandins and mechanical methods in pregnant women at or beyond 37 weeks of gestation.
Using prespecified criteria, study data abstraction and risk of bias assessment were conducted by two reviewers, random-effects meta-analyses were conducted and strength of evidence was assessed. We included 30 RCTs and 10 cohort studies (N=9,618) most generalizable to women aged 25-30 years with low-risk pregnancies. All findings were low or insufficient strength of evidence and not statistically significant. Incidence of cesarean delivery was not different for any comparison of inpatient and outpatient settings, or comparisons of different methods in the outpatient setting (most evidence available for single-balloon catheters and dinoprostone). Harms were inconsistently reported or inadequately defined. Differences were not found for neonatal infection (eg, sepsis) with outpatient compared with inpatient dinoprostone, birth trauma (eg, cephalohematoma) with outpatient compared with inpatient single-balloon catheter, shoulder dystocia with outpatient dinoprostone compared with placebo, maternal infection (eg, chorioamnionitis) with outpatient compared with inpatient single-balloon catheters or outpatient prostaglandins compared with placebo, and postpartum hemorrhage with outpatient catheter compared with inpatient dinoprostone. Evidence on misoprostol, hygroscopic dilators, and other outcomes (eg, perinatal mortality and time to vaginal birth) was insufficient.
In women with low-risk pregnancies, outpatient cervical ripening with dinoprostone or single-balloon catheters did not increase cesarean deliveries. Although there were no clear differences in harms when comparing outpatient with inpatient cervical ripening, the certainty of evidence is low or insufficient to draw definitive conclusions.
PROSPERO, CRD42020167406.
Background
Beyond term, the risks of stillbirth or neonatal death increase. It is unclear whether a policy of labour induction can reduce these risks. This Cochrane review is an update of a review ...that was originally published in 2006 and subsequently updated in 2012
Objectives
To assess the effects of a policy of labour induction at or beyond term compared with a policy of awaiting spontaneous labour or until an indication for birth induction of labour is identified) on pregnancy outcomes for infant and mother.
Search methods
We searched Cochrane Pregnancy and Childbirth’s Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (9 October 2017), and reference lists of retrieved studies.
Selection criteria
Randomised controlled trials (RCTs) conducted in pregnant women at or beyond term, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in form only. Cluster‐RCTs, quasi‐RCTs and trials using a cross‐over design are not eligible for inclusion in this review.
We included pregnant women at or beyond term. Since a risk factor at this stage of pregnancy would normally require an intervention, only trials including women at low risk for complications were eligible. We accepted the trialists' definition of 'low risk'. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane review.
Data collection and analysis
Two reviewers independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the quality of evidence using the GRADE approach.
Main results
In this updated review, we included 30 RCTs (reporting on 12,479 women). The trials took place in Norway, China, Thailand, the USA, Austria, Turkey, Canada, UK, India, Tunisia, Finland, Spain, Sweden and the Netherlands. They were generally at a moderate risk of bias.
Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all‐cause) perinatal deaths (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.14 to 0.78; 20 trials, 9960 infants; moderate‐quality evidence). There were two perinatal deaths in the labour induction policy group compared with 16 perinatal deaths in the expectant management group. The number needed to treat to for an additional beneficial outcome (NNTB) with induction of labour in order to prevent one perinatal death was 426 (95% CI 338 to 1337). There were fewer stillbirths in the induction group (RR 0.33, 95% CI 0.11 to 0.96; 20 trials, 9960 infants; moderate‐quality evidence); there was one stillbirth in the induction policy arm and 10 in the expectant management group.
For women in the policy of induction arms of trials, there were fewer caesarean sections compared with expectant management (RR 0.92, 95% CI 0.85 to 0.99; 27 trials, 11,738 women; moderate‐quality evidence); and a corresponding marginal increase in operative vaginal births with induction (RR 1.07, 95% CI 0.99 to 1.16; 18 trials, 9281 women; moderate‐quality evidence). There was no evidence of a difference between groups for perineal trauma (RR 1.09, 95% CI 0.65 to 1.83; 4 trials; 3028 women; low‐quality evidence), postpartum haemorrhage (RR 1.09 95% CI 0.92 to 1.30, 5 trials; 3315 women; low‐quality evidence), or length of maternal hospital stay (average mean difference (MD) ‐0.34 days, 95% CI ‐1.00 to 0.33; 5 trials; 1146 women; Tau² = 0.49; I² 95%; very low‐quality evidence).
Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.77 to 1.01; 13 trials, 8531 infants; moderate‐quality evidence) and fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.70, 95% CI 0.50 to 0.98; 16 trials, 9047 infants; moderate‐quality evidence).
There was no evidence of a difference for neonatal trauma (RR 1.18, 95% CI 0.68 to 2.05; 3 trials, 4255 infants; low‐quality evidence), for induction compared with expectant management.
Neonatal encephalopathy, neurodevelopment at childhood follow‐up, breastfeeding at discharge and postnatal depression were not reported by any trials.
In subgroup analyses, no clear differences between timing of induction (< 41 weeks versus ≥ 41 weeks' gestation) or by state of cervix were seen for perinatal death, stillbirth, NICU admission, caesarean section, or perineal trauma. However, operative vaginal birth was more common in the inductions at < 41 weeks' gestation subgroup compared with inductions at later gestational ages. The majority of trials (about 75% of participants) adopted a policy of induction at ≥ 41 weeks (> 287 days) gestation for the intervention arm.
Authors' conclusions
A policy of labour induction at or beyond term compared with expectant management is associated with fewer perinatal deaths and fewer caesarean sections; but more operative vaginal births. NICU admissions were lower and fewer babies had low Apgar scores with induction. No important differences were seen for most of the other maternal and infant outcomes.
Most of the important outcomes assessed using GRADE had a rating of moderate or low‐quality evidence ‐ with downgrading decisions generally due to study limitations such as lack of blinding (a condition inherent in comparisons between a policy of acting and of waiting), or imprecise effect estimates. One outcome (length of maternal stay) was downgraded further to very low‐quality evidence due to inconsistency.
Although the absolute risk of perinatal death is small, it may be helpful to offer women appropriate counselling to help choose between scheduled induction for a post‐term pregnancy or monitoring without (or later) induction).
The optimal timing of offering induction of labour to women at or beyond term warrants further investigation, as does further exploration of risk profiles of women and their values and preferences. Individual participant meta‐analysis is likely to help elucidate the role of factors, such as parity, in influencing outcomes of induction compared with expectant management.
Balloon labour induction and the price of elegance Hofmeyr, George Justus
BJOG : an international journal of obstetrics and gynaecology,
December 2020, 2020-12-00, 20201201, Volume:
127, Issue:
13
Journal Article
Peer reviewed
Open access
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The risk of perinatal death and severe neonatal morbidity increases gradually after 41 weeks of pregnancy. Several randomised controlled trials (RCTs) have assessed if induction of labour (IOL) in ...uncomplicated pregnancies at 41 weeks will improve perinatal outcomes. We performed an individual participant data meta-analysis (IPD-MA) on this subject.
We searched PubMed, Excerpta Medica dataBASE (Embase), The Cochrane Library, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and PsycINFO on February 21, 2020 for RCTs comparing IOL at 41 weeks with expectant management until 42 weeks in women with uncomplicated pregnancies. Individual participant data (IPD) were sought from eligible RCTs. Primary outcome was a composite of severe adverse perinatal outcomes: mortality and severe neonatal morbidity. Additional outcomes included neonatal admission, mode of delivery, perineal lacerations, and postpartum haemorrhage. Prespecified subgroup analyses were conducted for parity (nulliparous/multiparous), maternal age (<35/≥35 years), and body mass index (BMI) (<30/≥30). Aggregate data meta-analysis (MA) was performed to include data from RCTs for which IPD was not available. From 89 full-text articles, we identified three eligible RCTs (n = 5,161), and two contributed with IPD (n = 4,561). Baseline characteristics were similar between the groups regarding age, parity, BMI, and higher level of education. IOL resulted overall in a decrease of severe adverse perinatal outcome (0.4% 10/2,281 versus 1.0% 23/2,280; relative risk RR 0.43 95% confidence interval CI 0.21 to 0.91, p-value 0.027, risk difference RD -57/10,000 95% CI -106/10,000 to -8/10,000, I2 0%). The number needed to treat (NNT) was 175 (95% CI 94 to 1,267). Perinatal deaths occurred in one (<0.1%) versus eight (0.4%) pregnancies (Peto odds ratio OR 0.21 95% CI 0.06 to 0.78, p-value 0.019, RD -31/10,000, 95% CI -56/10,000 to -5/10,000, I2 0%, NNT 326, 95% CI 177 to 2,014) and admission to a neonatal care unit ≥4 days occurred in 1.1% (24/2,280) versus 1.9% (46/2,273), (RR 0.52 95% CI 0.32 to 0.85, p-value 0.009, RD -97/10,000 95% CI -169/10,000 to -26/10,000, I2 0%, NNT 103 95% CI 59 to 385). There was no difference in the rate of cesarean delivery (10.5% versus 10.7%; RR 0.98, 95% CI 0.83 to 1.16, p-value 0.81) nor in other important perinatal, delivery, and maternal outcomes. MA on aggregate data showed similar results. Prespecified subgroup analyses for the primary outcome showed a significant difference in the treatment effect (p = 0.01 for interaction) for parity, but not for maternal age or BMI. The risk of severe adverse perinatal outcome was decreased for nulliparous women in the IOL group (0.3% 4/1,219 versus 1.6% 20/1,264; RR 0.20 95% CI 0.07 to 0.60, p-value 0.004, RD -127/10,000, 95% CI -204/10,000 to -50/10,000, I2 0%, NNT 79 95% CI 49 to 201) but not for multiparous women (0.6% 6/1,219 versus 0.3% 3/1,264; RR 1.59 95% CI 0.15 to 17.30, p-value 0.35, RD 27/10,000, 95% CI -29/10,000 to 84/10,000, I2 55%). A limitation of this IPD-MA was the risk of overestimation of the effect on perinatal mortality due to early stopping of the largest included trial for safety reasons after the advice of the Data and Safety Monitoring Board. Furthermore, only two RCTs were eligible for the IPD-MA; thus, the possibility to assess severe adverse neonatal outcomes with few events was limited.
In this study, we found that, overall, IOL at 41 weeks improved perinatal outcome compared with expectant management until 42 weeks without increasing the cesarean delivery rate. This benefit is shown only in nulliparous women, whereas for multiparous women, the incidence of mortality and morbidity was too low to demonstrate any effect. The magnitude of risk reduction of perinatal mortality remains uncertain. Women with pregnancies approaching 41 weeks should be informed on the risk differences according to parity so that they are able to make an informed choice for IOL at 41 weeks or expectant management until 42 weeks. Study Registration: PROSPERO CRD42020163174.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Abnormal blood flow patterns in fetal circulation detected by Doppler ultrasound may indicate poor fetal prognosis. It is also possible that false positive Doppler ultrasound findings ...could lead to adverse outcomes from unnecessary interventions, including preterm delivery.
Objectives
The objective of this review was to assess the effects of Doppler ultrasound used to assess fetal well‐being in high‐risk pregnancies on obstetric care and fetal outcomes.
Search methods
We updated the search of Cochrane Pregnancy and Childbirth's Trials Register on 31 March 2017 and checked reference lists of retrieved studies.
Selection criteria
Randomised and quasi‐randomised controlled trials of Doppler ultrasound for the investigation of umbilical and fetal vessels waveforms in high‐risk pregnancies compared with no Doppler ultrasound. Cluster‐randomised trials were eligible for inclusion but none were identified.
Data collection and analysis
Two review authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. We assessed the quality of evidence using the GRADE approach.
Main results
Nineteen trials involving 10,667 women were included. Risk of bias in trials was difficult to assess accurately due to incomplete reporting. None of the evidence relating to our main outcomes was graded as high quality. The quality of evidence was downgraded due to missing information on trial methods, imprecision in risk estimates and heterogeneity. Eighteen of these studies compared the use of Doppler ultrasound of the umbilical artery of the unborn baby with no Doppler or with cardiotocography (CTG). One more recent trial compared Doppler examination of other fetal blood vessels (ductus venosus) with computerised CTG.
The use of Doppler ultrasound of the umbilical artery in high‐risk pregnancy was associated with fewer perinatal deaths (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.52 to 0.98, 16 studies, 10,225 babies, 1.2% versus 1.7 %, number needed to treat (NNT) = 203; 95% CI 103 to 4352, evidence graded moderate). The results for stillbirths were consistent with the overall rate of perinatal deaths, although there was no clear difference between groups for this outcome (RR 0.65, 95% CI 0.41 to 1.04; 15 studies, 9560 babies, evidence graded low). Where Doppler ultrasound was used, there were fewer inductions of labour (average RR 0.89, 95% CI 0.80 to 0.99, 10 studies, 5633 women, random‐effects, evidence graded moderate) and fewer caesarean sections (RR 0.90, 95% CI 0.84 to 0.97, 14 studies, 7918 women, evidence graded moderate). There was no comparative long‐term follow‐up of babies exposed to Doppler ultrasound in pregnancy in women at increased risk of complications.
No difference was found in operative vaginal births (RR 0.95, 95% CI 0.80 to 1.14, four studies, 2813 women), nor in Apgar scores less than seven at five minutes (RR 0.92, 95% CI 0.69 to 1.24, seven studies, 6321 babies, evidence graded low). Data for serious neonatal morbidity were not pooled due to high heterogeneity between the three studies that reported it (1098 babies) (evidence graded very low).
The use of Doppler to evaluate early and late changes in ductus venosus in early fetal growth restriction was not associated with significant differences in any perinatal death after randomisation. However, there was an improvement in long‐term neurological outcome in the cohort of babies in whom the trigger for delivery was either late changes in ductus venosus or abnormalities seen on computerised CTG.
Authors' conclusions
Current evidence suggests that the use of Doppler ultrasound on the umbilical artery in high‐risk pregnancies reduces the risk of perinatal deaths and may result in fewer obstetric interventions. The results should be interpreted with caution, as the evidence is not of high quality. Serial monitoring of Doppler changes in ductus venosus may be beneficial, but more studies of high quality with follow‐up including neurological development are needed for evidence to be conclusive.
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