Discontinuation of oxytocin in the active phase of labor

Impact of discontinuing oxytocin in active labour on neonatal morbidity: an open-label, multicentre, randomised trial

BACKGROUND

Oxytocin is effective in reducing labour duration but can be associated with fetal and maternal complications that could potentially be reduced by discontinuing the treatment during labour. We aimed to assess the impact of discontinuing oxytocin during active labour on neonatal morbidity.

METHODS

STOPOXY was a multicentre, randomised, open-label, controlled, superiority trial conducted in 21 maternity units in France. Participants who received oxytocin before 4 cm dilation were randomly assigned 1:1 to either discontinuous oxytocin (oxytocin infusion stopped beyond a cervical dilation equal to or greater than 6 cm) or continuous oxytocin (administration of oxytocin continued until delivery). Randomisation was stratified by centre and parity. The primary outcome, neonatal morbidity, was assessed at birth using a composite variable defined by an umbilical arterial pH at birth less than 7·10, a base excess greater than 10 mmol/L, umbilical arterial lactates greater than 7 mmol/L, a 5-min Apgar score less than 7, or admission to the neonatal intensive care unit. Efficacy and safety was assessed in participants who were randomly assigned (excluding those who withdrew consent or were deemed ineligible after randomisation) and had reached a cervical dilation of at least 6 cm. This trial is registered with ClinicalTrials.gov, NCT03991091.

FINDINGS

Of 2459 participants randomly assigned between Jan 13, 2020, and Jan 24, 2022, 2170 were eligible to receive the intervention and were included in the final modified intention-to-treat analysis. The primary outcome occurred for 102 (9·6%) of 1067 participants (95% CI 7·9 to 11·5) in the discontinuous oxytocin group and for 101 (9·2%) of 1103 participants (7·6 to 11·0) in the continuous oxytocin group; absolute difference 0·4% (95% CI -2·1 to 2·9); relative risk 1·0 (95% CI 0·8 to 1·4). There were no clinically significant differences in adverse events between the two groups of the safety population.

INTERPRETATION

Among participants receiving oxytocin in early labour, discontinuing oxytocin when the active phase is reached does not clinically or statistically significantly reduce neonatal morbidity compared with continuous oxytocin.

FUNDING

French Ministry of Health and the Département de la Recherche Clinique et du Développement de l'Assistance Publique-Hôpitaux de Paris.

Reducing neonatal morbidity by discontinuing oxytocin during the active phase of first stage of labor: a multicenter randomized controlled trial STOPOXY

BACKGROUND

Oxytocin is effective in reducing labor duration, but can be associated with fetal and maternal complications such as neonatal acidosis and post-partum hemorrhage. When comparing discontinuing oxytocin in the active phase with continuing oxytocin infusion, previous studies were underpowered to show a reduction in neonatal morbidity. Thus, we aim at evaluating the impact of discontinuing oxytocin during the active phase of the first stage of labor on the neonatal morbidity rate.

METHODS

STOPOXY is a multicenter, randomized, open-label, controlled trial conducted in 20 maternity units in France. The first participant was recruited January 17th 2020. The trial includes women with a live term (≥37 weeks) singleton, in cephalic presentation, receiving oxytocin before 4 cm, after an induced or spontaneous labor. Women aged < 18 years, with a lack of social security coverage, a scarred uterus, a multiple pregnancy, a fetal congenital malformation, a growth retardation <3rd percentile or an abnormal fetal heart rate at randomization are excluded. Women are randomized before 6 cm when oxytocin is either continued or discontinued. Randomization is stratified by center and parity. The primary outcome, neonatal morbidity is assessed using a composite variable defined by an umbilical arterial pH at birth < 7.10 and/or a base excess > 10 mmol/L and/or umbilical arterial lactates> 7 mmol/L and/or a 5 min Apgar score < 7 and/or admission in neonatal intensive care unit. The primary outcome will be compared between the two groups using a chi-square test with a p-value of 0.05. Secondary outcomes include neonatal complications, duration of active phase, mode of delivery, fetal and maternal complications during labor and delivery, including cesarean delivery rate and postpartum hemorrhage, and birth experience. We aim at including 2475 women based on a reduction in neonatal morbidity from 8% in the control group to 5% in the experimental group, with a power of 80% and an alpha risk of 5%.

DISCUSSION

Discontinuing oxytocin during the active phase of labor could improve both child health, by reducing moderate to severe neonatal morbidity, and maternal health by reducing cesarean delivery and postpartum hemorrhage rates.

TRIAL REGISTRATION

Clinical trials NCT03991091 , registered June 19th, 2019.

CONDISOX- continued versus discontinued oxytocin stimulation of induced labour in a double-blind randomised controlled trial

BACKGROUND

Oxytocin is an effective drug for induction of labour, but is associated with serious adverse effects of which uterine tachysystole, fetal distress and the need of immediate delivery are the most common. Discontinuation of oxytocin once the active phase of labour is established could reduce the adverse effects. The objective is to investigate how the caesarean section rate is affected when oxytocin stimulation is discontinued in the active phase of labour compared to labours where oxytocin is continued.

METHODS

CONDISOX is a double-blind multicentre randomised controlled trial conducted at Danish and Dutch Departments of Obstetrics and Gynaecology. The first participant was recruited on April 8 2016. Based on a clinically relevant relative reduction in caesarean section rate of 7%, an alpha of 0.05, a beta of 80%, we aim for 1200 participating women (600 in each arm). The CONDISOX trial includes women at a gestational age of 37-42 complete weeks of pregnancy, who have uterine activity stimulated with oxytocin infusion for the induction of labour. Women are randomised when the active phase of labour becomes established, to study medication containing either oxytocin (continuous group) or placebo (discontinued group) infusion. Women are stratified by birth site, indication for oxytocin stimulation (induction of labour, prelabour rupture of membranes) and parity (nulliparous, parous +/- previous caesarean section). We will compare the primary outcome, caesarean section rate, in the two groups using a chi-square test with a p-value of 0.05. If superiority is not demonstrated, we have a pre-defined post hoc non-inferiority boundary (margin, delta) at 1.09. Secondary outcomes include duration of the active phase of labour, incidence of uterine tachysystole, postpartum haemorrhage, admission to the neonatal intensive care unit, Apgar score, umbilical arterial blood pH, and birth experience.

DISCUSSION

The high frequency of oxytocin use and the potential risks of both maternal and fetal adverse effects of oxytocin emphasise the need to determine the optimal oxytocin regime for induction of labour.

TRIAL REGISTRATION

NCT02553226 (registered September 17, 2015). Eudra-CT number: 2015-002942-30.

Continuous oxytocin versus intermittent oxytocin for induction of labor: a randomized study

Objective: To assess whether intermittent usage of oxytocin infusion increases the duration of the active phase of labor and reduces maternal and neonatal complications or not.Materials and Methods: A prospective randomized controlled study was conducted of 200 consenting women with singleton pregnancy in the vertex position undergoing labor induction or augmentation at the Zeynep Kamil Maternity and Children's Training and Research Hospital. Participants with cervical dilation of 3 cm were randomized to either continued or intermittent oxytocin infusion when cervical dilation reached 5 cm. The primary outcome measures were the duration of the active phase of labor, defined as the period of labor from 5 cm of cervical dilation to vaginal delivery. Secondary outcomes were the duration of oxytocin infusion, mode of delivery, hyperstimulation, abnormalities in fetal heart rate, perineal tears, and neonatal outcomes.Results: The median duration of the active phase for the women with a vaginal delivery was longer in the intermittent oxytocin group than the continued oxytocin group, but it was not statistically significant (median, 6.91 vs. 7.58 h, p = .37). There was a significant difference in the duration of oxytocin infusion (median, 12.38 h in the intermittent group vs. 15.79 h in the continued group, p = .005). The incidence of uterine hyperstimulation was significantly greater in the continued group (21.1%) than the intermittent oxytocin group (3.8%) (p=.001).Conclusions: Intermittent usage of oxytocin infusion seems to make labor less complicated without lengthening duration of labor.

Discontinuation of intravenous oxytocin in the active phase of induced labour

BACKGROUND

In most Western countries, obstetricians and midwives induce labour in about 25% of pregnant women. Oxytocin is an effective drug for this purpose, but associated with serious adverse effects of which uterine tachysystole, fetal distress and the need for immediate delivery are the most common. Various administration regimens such as reduced or pulsatile dosing have been suggested to minimise these. Discontinuation in the active phase of labour, i.e. when contractions are well-established and the cervix is dilated at least 5 cm is another method which may reduce adverse effects.

OBJECTIVES

To assess whether birth outcomes can be improved by discontinuation of intravenous (IV) oxytocin, initiated in the latent phase of induced labour, once active phase of labour is established.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (31 January 2018), Scopus, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) (23 January 2018) together with reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing discontinued IV with continuous IV oxytocin in the active phase of induced labour.No exclusion criteria were applied in terms of parity, maternal age, ethnicity, co-morbidity status, labour setting, gestational age, and prior caesarean delivery.Studies comparing different dosage regimens are outside the scope of this review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods.

MAIN RESULTS

We found 10 completed RCTs involving 1888 women. One additional trial is ongoing. The included trials were conducted in hospital settings between February 1998 and January 2016, two in Europe (Denmark, and Greece), two in Turkey, and one each in Israel, Iran, USA, Bangladesh, India, and Thailand. Most trials included full-term singleton pregnancies with a fetus in vertex presentation. Some excluded women with cervical priming prior to induction and some excluded women with a history of prior caesarean delivery. When reported, the average age of the women ranged from 22 to 31 years, nulliparity from 45% to 68%, and pre-pregnancy body mass index from 22 to 32.Many of the included trials had design limitations and were judged to be at either high or unclear risk of bias across a number of 'Risk of bias' domains.Four trials included a Consort flow diagram. In three, this gave details of participants delivered before the active phase of labour, and treatment compliance for those who reached that stage. One Consort diagram only provided the latter information. The data in many of the trials without such a flow diagram were implausibly compliant with treatment allocation, suggesting that there had been silent post randomisation exclusions of women delivered before the active phase of labour. We therefore conducted a secondary analysis (not in our protocol) of caesarean section among women who reached the active phase of labour and were therefore eligible for the intervention.Our analysis by 'intention-to-treat' found that, compared with continuation of IV oxytocin stimulation, discontinuation of IV oxytocin may reduce the caesarean delivery rate, risk ratio (RR) 0.69, 95% confidence interval (CI) 0.56 to 0.86, 9 trials, 1784 women, low-level certainty. However, restricting our analysis to women who reached the active phase of labour (using 'reached active phase' as our denominator) suggests there is probably little or no difference between groups (RR 0.92, 95% CI 0.65 to 1.29, 4 trials, 787 women, moderate-certainty evidence).Discontinuation of IV oxytocin probably reduces the risk ofuterine tachysystole combined with abnormal fetal heart rate (FHR) compared with continued IV oxytocin (RR 0.15, 95% CI 0.05 to 0.46, 3 trials, 486 women, moderate-level certainty). We are uncertain about whether or not discontinuation increases the risk of chorioamnionitis (average RR 2.32, 95% CI 0.99 to 5.45, 1 trial, 252 women, very low-level certainty). Discontinuation of IV oxytocin may have little or no impact on the use of analgesia and epidural during labour compared to the use of continued IV oxytocin (RR 1.04 95% CI 0.95 to 1.14, 3 trials, 556 women, low-level certainty). Intrapartum cardiotocography (CTG) abnormalities (suspicious/pathological CTGs) are probably reduced by discontinuing IV oxytocin (RR 0.65, 95% CI 0.51 to 0.83, 7 trials, 1390 women, moderate-level certainty). Compared to continuing IV oxytocin, discontinuing IV oxytocin probably has little or no impact on the incidence of Apgar < 7 at five minutes (RR 0.78, 95% CI 0.27 to 2.21, 4 trials, 893 women, low-level certainty), or and acidotic cord gasses at birth (arterial umbilical pH < 7.10), (RR 1.03, 95% CI 0.50 to 2.13, 4 trials, 873 women, low-level certainty).Many of this review's maternal and infant secondary outcomes (including maternal and neonatal mortality) were not reported in the included trials.

AUTHORS' CONCLUSIONS

Discontinuing IV oxytocin stimulation after the active phase of labour has been established may reduce caesarean delivery but the evidence for this was low certainty. When restricting our analysis to those trials that separately reported participants who reached the active phase of labour, our results showed there is probably little or no difference between groups. Discontinuing IV oxytocin may reduce uterine tachysystole combined with abnormal FHR.Most of the trials had 'Risk of bias' concerns which means that these results should be interpreted with caution. Our GRADE assessments ranged from very low certainty to moderate certainty. Downgrading decisions were based on study limitations, imprecision and indirectness.Future research could account for all women randomised and, in particular, note those who delivered before the point at which they would be eligible for the intervention (i.e. those who had caesareans in the latent phase), or because labour was so rapid that the infusion could not be stopped in time.Future trials could adopt the outcomes listed in this review including maternal and neonatal mortality, maternal satisfaction, and breastfeeding.

Oxytocin discontinuation after the active phase of induced labor: A systematic review

BACKGROUND

Oxytocin is the most widely used drug in the induction of labor, but it could have potential adverse effects that derive from uterine hyperstimulation.

AIM

To determine the benefits and drawbacks of oxytocin continuation versus oxytocin discontinuation after the active phase of induced labor.

METHODS

We systematically searched Pubmed, EMBASE, Scopus, ClinicalTrials.gov and Cochrane Library Plus until October 2017, for randomized controlled trials comparing oxytocin continuation with oxytocin discontinuation when the active phase of labor is reached were included. Data was collected by three reviewers and quality of the included studies assessed using the methodology recommended in the Cochrane Handbook. StatsDirect software was used to calculate risk ratios for binary variables and weighted mean differences for continuous variables. A fixed-effects or random-effects model was used as appropriate.

RESULTS

Nine studies were selected including 1538 women, 774 in the oxytocin continuation group and 764 in the oxytocin discontinuation group. The incidence of cesarean sections (14.3% vs. 8.6%; relative risk, 1.67; 95% confidence interval: 1.25-2.23), uterine hyperstimulation (12.4% vs. 4.7%; relative risk, 2.59; 95% confidence interval: 1.70-3.93) and nonreassuring fetal heart rate (19.2% vs.12.5%; relative risk, 1.55; 95% confidence interval: 1.18-2.02) were significantly higher in the oxytocin continuation group. An increase in the duration of the second stage of labor in the oxytocin discontinuation group was observed (pooled mean difference, -7.03; 95% confidence interval: -9.80 to -4.26).

CONCLUSIONS

After the active phase of induced labor, oxytocin continuation increases the risk of cesarean section, uterine hyperstimulation and alterations to the fetal heart rate.

High-dose compared with low-dose oxytocin for induction of labour of nulliparous women at term

BACKGROUND

The optimal oxytocin infusion regimen to induce labour with the lowest caesarean section rate, instrumental delivery rate and length of active labour is unclear. We compared the effect of a low-dose to high-dose oxytocin regimen to induce labour.

MATERIALS AND METHODS

We conducted a retrospective study of nulliparous women induced at term in a single tertiary centre from 2009 to 2015. The oxytocin induction protocol changed from a high to low-dose regimen in November 2012, affording us the opportunity to compare outcomes 3 years prior to, and following the change in protocol. Main outcome measures were caesarean section rate, instrumental delivery rate and length of active labour.

RESULTS

Four thousand eight hundred and eighty-five participants were included, 2211 were induced via the low-dose regimen, and 2674 using the high-dose regimen. There was no difference in caesarean section rate (adjusted OR 0.99; 95% CI 0.87-1.13) or instrumental delivery rates once adjusted for regional anaesthesia (adjusted OR 1.16; 95% CI 0.99-1.36) between the different regimens. Surprisingly, the length of labour was longer in the high-dose oxytocin group (adjusted mean difference 0.60 h; 95%CI 0.81-0.12). There were significantly more postpartum haemorrhage ≥1000 ml (10.5% versus 7.8%, p < .001) and regional anaesthesia use (55.8% versus 52.1%, p = .03) in the low-dose cohort. There were no differences in neonatal outcomes.

CONCLUSION

Outcomes between high- and low-dose oxytocin induction regimens are relatively comparable with similar caesarean section and instrumental delivery rates. Therefore, either regimen is acceptable for use for induction of labour.

Stopping Oxytocin in Active Labor Rather Than Continuing it until Delivery: A Viable Option for the Induction of Labor

OBJECTIVE

Induction of labor (IOL), using intravenous oxytocin, is the artificial initiation of labor before its spontaneous onset for the purpose of delivery of the fetoplacental unit. Although there are various studies looking at dosages of oxytocin, only a few have addressed the issue of discontinuation of oxytocin in the active stage of labor. Thus, our study was conducted to evaluate the need for continuation versus discontinuation of oxytocin during active labor.

METHODS

This prospective, randomized controlled trial included 106 women who needed IOL. Oxytocin infusion was initiated at a rate of 3mIU/min and was incremental until 4-6cm cervical dilation. At this point the patients were randomly assigned into one of two groups. In group one, oxytocin was discontinued, and infusion was continued with 0.9% sodium chloride solution. In group two, oxytocin was continued at the same dose until delivery.

RESULTS

The duration of oxytocin infusion was 5.5 hours in the oxytocin discontinuation group and 11.0 hours in oxytocin continuation group (p<0.001). The total dose of oxytocin was significantly higher in group two (6.1 units vs. 16.5 units; p=<0.001). The induction-delivery interval was significantly less in group one (9.1 and 11.2 hours in group one and group two, respectively; p=0.023).

CONCLUSION

Oxytocin discontinuation in the active stage of labor did not prolong the active stage. The total duration of labor and total oxytocin dose were significantly less in the oxytocin discontinuation group. Our results suggest that oxytocin discontinuation is an alternative and viable option particularly in resource poor and economically challenged settings. It not only reduces the need for intense monitoring and prolonged oxytocin use-associated dangers but reduces the total cost of labor management.

Pharmacotherapy options for labor induction

INTRODUCTION

Induction of labor remains one of the most commonly performed procedures in the US and in other developed countries around the world. Various agents for cervical ripening are used prior to induction; the most commonly used are prostaglandins and oxytocin. The ideal agent is one that decreases time to vaginal delivery without compromising maternal and/or fetal safety.

AREAS COVERED

This article reviews the current pharmacologic methods available for induction of labor. Although these agents have been extensively studied and their safety and efficacy profile are well accepted, there is still ongoing research to determine the safest and most effective method. The article discusses the impact of pharmacogenomics as it relates to the most common induction agents. The dosing, route of administration, and side effects of these agents are reviewed.

EXPERT OPINION

Prostaglandins and oxytocin have been proven to be safe and effective methods of induction. However, the optimal medication for induction is yet to be determined. Although there are currently no pharmacogenomic findings that affect dosing of either prostaglandins or oxytocin, this is a growing area of research. In the near future, it may become clear that there is no 'one regimen for all' when selecting an induction or cervical ripening agent, or any other pharmaceutical altogether.

High-dose versus low-dose oxytocin infusion regimens for induction of labour at term

BACKGROUND

When women require induction of labour, oxytocin is the most common agent used, delivered by an intravenous infusion titrated to uterine contraction strength and frequency. There is debate over the optimum dose regimen and how it impacts on maternal and fetal outcomes, particularly induction to birth interval, mode of birth, and rates of hyperstimulation. Current induction of labour regimens include both high- and low-dose regimens and are delivered by either continuous or pulsed infusions, with both linear and non-linear incremental increases in oxytocin dose. Whilst low-dose protocols bring on contractions safely, their potentially slow induction to birth interval may increase the chance of fetal infection and chorioamnionitis. Conversely, high-dose protocols may cause undue uterine hyperstimulation and fetal distress.

OBJECTIVES

To determine the effectiveness and safety of high- versus low-dose oxytocin for induction of labour at term

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2014) and the reference lists of relevant papers.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials that compared oxytocin protocol for induction of labour for women at term, where high-dose oxytocin is at least 100 mU oxytocin in the first 40 minutes, with increments delivering at least 600 mU in the first two hours, compared with low-dose oxytocin, defined as less than 100 mU oxytocin in the first 40 minutes, and increments delivering less than 600 mU total in the first two hours.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy.

MAIN RESULTS

We have included nine trials, involving 2391 women and their babies in this review. Trials were at a moderate to high risk of bias overall.Results of primary outcomes revealed no significant differences in rates of vaginal delivery not achieved within 24 hours (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.78 to 1.14, two trials, 1339 women) or caesarean section (RR 0.96, 95% CI 0.81 to 1.14, eight trials, 2023 women). There was no difference in serious maternal morbidity or death (RR 1.24, 95% CI 0.55 to 2.82, one trial, 523 women), and no difference in serious neonatal morbidity or perinatal death (RR 0.84, 95% CI 0.23 to 3.12, one trial, 781 infants). Finally, no trials reported on the number of women who had uterine hyperstimulation with fetal heart rate changes.Results of secondary outcomes revealed no difference between time from induction to delivery (mean difference (MD) -0.90 hours, 95% CI -2.28 to +0.49 hours; five studies), uterine rupture (RR 3.10, 95% CI 0.50 to 19.33; three trials), epidural analgesia (RR 1.03, 95% CI 0.89 to 1.18; two trials), instrumental birth (RR 1.22, 95% CI 0.88 to 1.66; three trials), Apgar less than seven at five minutes (RR 1.25, 95% CI 0.77 to 2.01, five trials), perinatal death (RR 0.84, 95% CI 0.23 to 3.12; two trials), postpartum haemorrhage (RR 1.08, 95% CI 0.87 to 1.34; five trials), or endometritis (RR 1.35, 95% CI 0.53 to 3.43; three trials). Removal of high bias studies reveals a significant reduction of induction to delivery interval (MD -1.94 hours, 95% CI -0.99 to -2.89 hours, 489 women). A significant increase in hyperstimulation without specifying fetal heart rate changes was found in the high-dose group (RR 1.86, 95% CI 1.55 to 2.25).No other secondary outcomes were reported: unchanged/unfavourable cervix after 12 to 24 hours, meconium-stained liquor, neonatal intensive care unit admission, neonatal encephalopathy, disability in childhood, other maternal side-effects (nausea, vomiting, diarrhoea), maternal antibiotic use, maternal satisfaction, neonatal infection and neonatal antibiotic use.

AUTHORS' CONCLUSIONS

The findings of our review do not provide evidence that high-dose oxytocin increases either vaginal delivery within 24 hours or the caesarean section rate. There is no significant decrease in induction to delivery time at meta-analysis but these results may be confounded by poor quality trials. High-dose oxytocin was shown to increase the rate of uterine hyperstimulation but the effects of this are not clear. The conclusions here are specific to the definitions used in this review. Further trials evaluating the effects of high-dose regimens of oxytocin for induction of labour should consider all important maternal and infant outcomes.

Oxytocin discontinuation after the active phase of labor is established

Despite the widespread usage of oxytocin, there is still no consensus on its mode of administration. The scope of the present meta-analysis was to assess the effect of oxytocin discontinuation after the active phase of labor is established on maternal fetal and neonatal outcomes. We searched Medline, Scopus, Popline, ClinicalTrials.gov and Google Scholar databases. Eight studies were finally retrieved, which involved 1232 parturient. We observed significantly decreased rates of cesarean sections among parturient that discontinued oxytocin (OR 0.51, 95% CI 0.35, 0.74) as well as decreased rates of uterine hyperstimulation (OR 0.33, 95% CI 0.19, 0.58). Similarly, cases of non-reassuring fetal heart rates were fewer among women that did not receive oxytocin after the establishment of the active phase of labor (OR 0.63, 95% CI 0.41, 0.97). Keeping in mind the aforementioned maternal and neonatal adverse effects that seem to result from infusion of oxytocin until delivery, future practice should aim towards its discontinuation after the establishment of the active phase of labor, as it does not seem to influence the total duration of labor. Future studies should aim towards specific populations of parturient in order to clarify whether different approaches are needed.

Effect of oxytocin discontinuation during the active phase of labor

OBJECTIVE

To observe the progression of labor when oxytocin use is limited to the onset of the active stage of labor.

METHODS

A randomized, prospective controlled study was performed to address the issue of oxytocin infusion after the onset of active labor in 140 patients. In the study group, infusion of oxytocin was discontinued at the onset of the active phase of labor, which was accepted as a cervical dilatation of 5 cm. In the control group, incremental oxytocin infusion was administered until 5 cm cervical dilatation, and then was maintained at the same level until delivery.

RESULTS

The primary outcome variable was duration from the beginning of the active phase to delivery. In the study group, the duration of the active phase of labor was about 30 min longer than in the control group and this difference was significant. The secondary outcomes of the study were maternal-fetal complications of oxytocin and in both groups there were no significant differences.

CONCLUSION

It is not reasonable to discontinue oxytocin infusion at the beginning of active labor. Nevertheless, for an accurate conclusion expanded investigations are needed.

Oxytocin augmentation of labour in women with epidural analgesia for reducing operative deliveries

BACKGROUND

The rate of operative deliveries (both caesarean sections, vacuum extractions and forceps), continues to rise throughout the world. These are associated with significant maternal and neonatal morbidity. The most common reasons for operative births in nulliparous women are labour dystocia (failure to progress), and non-reassuring fetal status. Epidural analgesia has been shown to slow the progress of labour, as well as increase the rate of instrumental deliveries. However, it is unclear whether the use of oxytocin in women with epidural analgesia results in a reduction in operative deliveries, and thereby reduces both maternal and fetal morbidity.

OBJECTIVES

To determine whether augmentation of women using epidural analgesia with oxytocin will decrease the incidence of operative deliveries and thereby reduce fetal and maternal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2013).

SELECTION CRITERIA

All published and unpublished randomised and quasi-randomised trials that compared augmentation with oxytocin of women in spontaneous labour with epidural analgesia versus intent to manage expectantly were included. Cluster-randomised trials were eligible for inclusion but none were identified.Cross-over study designs were unlikely to be relevant for this intervention, and we planned to exclude them if any were identified. We did not include results that were only available in published abstracts.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed for inclusion the 16 studies identified as a result of the search strategy. Both review authors independently assessed the risk of bias for each included study. Both review authors independently extracted data. Data were checked for accuracy.

MAIN RESULTS

We included two studies, involving 319 women. There was no statistically significant difference between the two groups in either of the primary outcomes of caesarean section (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.42 to 2.12) or instrumental delivery (RR 0.88, 95% CI 0.72 to 1.08). Similarly, there were no statistically significant differences between the two groups in any of the secondary outcomes for which data were available. This included Apgar score less than seven at five minutes (RR 3.06, 0.13 to 73.33), admission to neonatal intensive care unit (RR 1.07, 95% CI 0.29 to 3.93), uterine hyperstimulation (RR 1.32, 95% CI 0.97 to 1.80) and postpartum haemorrhage (RR 0.96, 95% CI 0.58, 1.59).

AUTHORS' CONCLUSIONS

There was no statistically significant difference identified between women in spontaneous labour with epidural analgesia who were augmented with oxytocin, compared with those who received placebo. However, due to the limited number of women included in the studies, further research in the form of randomised controlled trials are required.

Oxytocin discontinuation during active labor in women who undergo labor induction

OBJECTIVE

The purpose of this study was to determine whether there is an increase in the cesarean delivery rate in women who undergo induction when oxytocin is discontinued in the active phase of labor.

STUDY DESIGN

We conducted a prospective randomized controlled trial of women who underwent induction of labor at term; they were assigned randomly to either routine oxytocin use (routine) or oxytocin discontinuation (DC) once in active labor. Analysis was by intention to treat.

RESULTS

Two hundred fifty-two patients were eligible for study analysis: 127 patients were assigned randomly to the routine group and 125 patients were assigned randomly to the DC group. Cesarean delivery rate was similar between the groups (routine, 25.2% [n = 32] vs the DC group, 19.2% [n = 24]; P = .25). There was a higher chorioamnionitis rate and slightly longer active phase in those women who were assigned to the DC group. In adjusted analysis, the rate of chorioamnionitis was not different by randomization group but was explained by the duration of membrane rupture and intrauterine pressure catheter placement.

CONCLUSION

Discontinuation of oxytocin in active labor after labor induction does not increase the cesarean delivery rate significantly.

Increased intravenous hydration of nulliparas in labor

OBJECTIVE

To assess the effects of intravenous hydration on the duration of active labor in nulliparous women also allowed unrestricted oral consumption of fluids.

METHODS

In a randomized clinical trial 120 nulliparous women with uncomplicated singleton pregnancies at term were randomly assigned to drink fluids at will and receive either no intravenous hydration (group 1) or a Ringer lactate solution at rates of 60 mL, 120 mL, or 240 mL per hour (groups 2-4) throughout active labor.

RESULTS

There were differences in duration for the active phase of the first stage of labor (252.3 ± 40.9 min in group 1 vs 206.7±38.3 min in group 4; P<0.001) and for the second stage (64.3 ± 13.9 in group 1 vs 49.8 ± 11.4 min in group 4; P=0.01), but not for the third stage. The percentage of participants who needed labor augmentation with oxytocin was less when intravenous hydration was provided (53.3% in group 1 vs 20.0% in group 4; P=0.02).

CONCLUSION

Intravenous hydration significantly decreased the duration of active labor and reduced the frequency of both prolonged labor and oxytocin administration in nulliparous women. htpp://www.irct.ir registration number: IRCT201105256575N2.

Oxytocin augmentation of labour in women with epidural analgesia for reducing operative deliveries

BACKGROUND

The rate of operative deliveries (both caesarean sections, vacuum extractions and forceps), continues to rise throughout the world. These are associated with significant maternal and neonatal morbidity. The most common reasons for operative births in nulliparous women are labour dystocia (failure to progress), and non-reassuring fetal status. Epidural analgesia has been shown to slow the progress of labour, as well as increase the rate of instrumental deliveries. However, it is unclear whether the use of oxytocin in women with epidural analgesia results in a reduction in operative deliveries, and thereby reduces both maternal and fetal morbidity.

OBJECTIVES

To determine whether augmentation of women using epidural analgesia with oxytocin will decrease the incidence of operative deliveries and thereby reduce fetal and maternal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (29 February 2012).

SELECTION CRITERIA

All published and unpublished randomised and quasi-randomised trials that compared augmentation with oxytocin of women in spontaneous labour with epidural analgesia versus intent to manage expectantly were included. Cluster-randomised trials were eligible for inclusion but none were identified.Cross-over study designs were unlikely to be relevant for this intervention, and we planned to exclude them if any were identified. We did not include results that were only available in published abstracts.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed for inclusion the 16 studies identified as a result of the search strategy. Both review authors independently assessed the risk of bias for each included study. Both review authors independently extracted data. Data were checked for accuracy.

MAIN RESULTS

We included two studies, involving 319 women. There was no statistically significant difference between the two groups in either of the primary outcomes of caesarean section (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.42 to 2.12) or instrumental delivery (RR 0.88, 95% CI 0.72 to 1.08). Similarly, there were no statistically significant differences between the two groups in any of the secondary outcomes for which data were available. This included Apgar score less than seven at five minutes (RR 3.06, 0.13 to 73.33), admission to neonatal intensive care unit (RR 1.07, 95% CI 0.29 to 3.93), uterine hyperstimulation (RR 1.32, 95% CI 0.97 to 1.80) and postpartum haemorrhage (RR 0.96, 95% CI 0.58, 1.59).

AUTHORS' CONCLUSIONS

There was no statistically significant difference identified between women in spontaneous labour with epidural analgesia who were augmented with oxytocin, compared with those who received placebo. However, due to the limited number of women included in the studies, further research in the form of randomised controlled trials are required.