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Midwifery Aug 2023Both duration of labour and use of oxytocin for augmentation are known risk factors for postpartum haemorrhage but distinguishing between the significance of these... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Both duration of labour and use of oxytocin for augmentation are known risk factors for postpartum haemorrhage but distinguishing between the significance of these factors is complex. In this study, we aimed to investigate the association between both labour duration and oxytocin augmentation, for postpartum haemorrhage.
DESIGN
A cohort study based on a secondary analysis of a cluster-randomised trial.
PARTICIPANTS AND SETTING
Term nulliparous women with a single foetus in cephalic presentation, spontaneous onset of active labour and a vaginal birth. The participants were originally included in cluster-randomised trial conducted in Norway from December 1, 2014, to January 31, 2017, that aimed to compare the frequency of intrapartum caesarean sections when adhering to the WHO partograph versus Zhang's guideline.
MEASUREMENTS
The data were analysed through four statistical models. Model 1 investigated the effect of oxytocin augmentation as a dichotomous variable (yes/no); Model 2 investigated the effect of the duration of oxytocin augmentation; Model 3 investigated the effect of the maximum dose of oxytocin; and Model 4 investigated the effect of both the duration of augmentation and the maximum dose of oxytocin. All four models included duration of labour divided into five time-intervals. We used binary logistic regression to estimate the odds ratios of postpartum haemorrhage, defined as blood loss of ≥ 1000 ml, including a random intercept for hospital and mutually adjusting for oxytocin augmentation and labour duration in addition to maternal age, maternal marital status, maternal higher education level, maternal smoking habits in the first trimester, maternal body mass index and birth weight.
FINDINGS
Model 1 found a significant association between the use of oxytocin and postpartum haemorrhage. In Model 2, oxytocin augmentation of ≥ 4.5 h was associated with postpartum haemorrhage. In Model 3, we found an association between a maximum dose of oxytocin of ≥ 20 mU/min and postpartum haemorrhage. Model 4 showed that a maximum dose of oxytocin ≥ 20 mU/min was associated with postpartum haemorrhage both for those augmented < 4.5 h and for those augmented ≥ 4.5 h. Duration of labour was associated with postpartum haemorrhage in all models if lasting ≥ 16 h.
KEY CONCLUSIONS
We found both oxytocin augmentation and labour duration to be associated with postpartum haemorrhage. Oxytocin doses of ≥ 20 mU/min and a labour duration of ≥ 16 h showed an independent association.
IMPLICATION FOR PRACTICE
The potent drug oxytocin should be carefully administered, as doses of ≥ 20 mU/min were associated with an increased risk of PPH, regardless of the duration of oxytocin augmentation.
Topics: Pregnancy; Female; Humans; Oxytocin; Postpartum Hemorrhage; Oxytocics; Cohort Studies; Labor, Obstetric
PubMed: 37244235
DOI: 10.1016/j.midw.2023.103705 -
Archives of Gynecology and Obstetrics Sep 2023Misoprostol is a synthetic PGE analogue that is used for induction of labour. Current guidelines support the use of doses that do not exceed 25 mcg in order to limit... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Misoprostol is a synthetic PGE analogue that is used for induction of labour. Current guidelines support the use of doses that do not exceed 25 mcg in order to limit maternal and neonatal adverse outcomes. The present meta-analysis investigates the efficacy and safety of oral compared to vaginally inserted misoprostol in terms of induction of labor and adverse peripartum outcomes.
METHODS
We searched Medline, Scopus, the Cochrane Central Register of Controlled Trials CENTRAL, Google Scholar, and Clinicaltrials.gov databases from inception till April 2022. Randomized controlled trials that assessed the efficacy of oral misoprostol (per os or sublingual) compared to vaginally inserted misoprostol. Effect sizes were calculated in R. Sensitivity analysis was performed to evaluate the possibility of small study effects, p-hacking. Meta-regression and subgroup analysis according to the dose of misoprostol was also investigated. The methodological quality of the included studies was assessed by two independent reviewers using the risk of bias 2 tool. Quality of evidence for primary outcomes was evaluated under the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, ranging from very low to high.
RESULTS
Overall, 57 studies were included that involved 10,975 parturient. Their risk of bias ranged between low-moderate. There were no differences among the routes of intake in terms of successful vaginal delivery within 24 h (RR 0.90, 95% CI 0.80) and cesarean section rates (RR 0.92, 95% CI 0.82, 1.04). Sublingual misoprostol was superior compared to vaginal misoprostol in reducing the interval from induction to delivery (MD - 1.11 h, 95% CI - 2.06, - 0.17). On the other hand, per os misoprostol was inferior compared to vaginal misoprostol in terms of this outcome (MD 3.45 h, 95% CI 1.85, 5.06). Maternal and neonatal morbidity was not affected by the route or dose of misoprostol.
CONCLUSION
The findings of our study suggest that oral misoprostol intake is equally safe to vaginal misoprostol in terms of inducing labor at term. Sublingual intake seems to outperform the per os and vaginal routes without increasing the accompanying morbidity. Increasing the dose of misoprostol does not seem to increase its efficacy.
CLINICAL TRIAL REGISTRATION
Open Science Framework ( https://doi.org/10.17605/OSF.IO/V9JHF ).
Topics: Infant, Newborn; Pregnancy; Humans; Female; Misoprostol; Oxytocics; Cesarean Section; Labor, Induced; Administration, Sublingual
PubMed: 36472645
DOI: 10.1007/s00404-022-06867-9 -
PloS One 2021Sustainable Development Goal 3.1 calls for a reduction of the maternal mortality ratio to less than 70 per 100,000 live births by 2030. The most important cause of...
Sustainable Development Goal 3.1 calls for a reduction of the maternal mortality ratio to less than 70 per 100,000 live births by 2030. The most important cause of maternal mortality is post-partum haemorrhage (PPH). Oxytocin injections and misoprostol tablets are medicines of first choice for the management of PPH in low- and middle-income countries (LMICs). Unfortunately, both substances are chemically unstable, and previous studies have revealed serious quality problems of these medicines in LMICs. The present study is the first report on their quality in Rwanda. From 40 randomly selected health facilities (hospitals, health centers, retail pharmacies and private clinics) in different parts of Rwanda, as well as from six wholesalers and government stores, oxytocin injections and misoprostol tablets were collected. Oxytocin storage temperatures in the health facilities were monitored for six months using temperature data loggers, and found to correctly follow the storage requirements stated by the manufacturers (2-8°C, or room temperature) with few minor deviations. Oxytocin injections (57 samples, representing seven batches of four brands) were tested for their oxytocin content and pH value according to the United States Pharmacopeia. Twenty-four samples from three European manufacturers passed all tests. However, all nine samples of one batch of a Chinese manufacturer showed an excessive content of oxytocin (range 117.2-121.5% of the declared amount). Another batch of the same manufacturer showed extreme variations of the concentration of the preservative benzyl alcohol. Misoprostol tablets (25 samples, representing ten batches of six brands) were tested for content and dissolution according to the International Pharmacopoeia. Fifteen samples passed, but all 10 samples of two brands from India failed with extreme deviations, containing only 42.5-48.7% of the stated amount of misoprostol. In conclusion, oxytocin quality in Rwanda was better than reported from other African countries. However, two extremely substandard brands of misoprostol tablets were found. The Rwandan authorities reacted quickly and efficiently, and recalled these substandard medicines from the market. For oxytocin and misoprostol, with their well-known problems of quality and stability, procurement should possibly be restricted to medicines which are WHO-prequalified or which have been manufactured in countries with stringent regulatory authorities.
Topics: Drug Storage; Health Facilities; Humans; Oxytocics; Quality Assurance, Health Care; Quality Control; Rwanda
PubMed: 33417602
DOI: 10.1371/journal.pone.0245054 -
PloS One 2020To compare synthetic oxytocin infusion regimens used during labour, calculate the International Units (IU) escalation rate and total amount of IU infused over eight... (Review)
Review
OBJECTIVE
To compare synthetic oxytocin infusion regimens used during labour, calculate the International Units (IU) escalation rate and total amount of IU infused over eight hours.
DESIGN
Observational study.
SETTING
Twelve countries, eleven European and South Africa.
SAMPLE
National, regional or institutional-level regimens on oxytocin for induction and augmentation labour.
METHODS
Data on oxytocin IU dose, infusion fluid amount, start dose, escalation rate and maximum dose were collected. Values for each regimen were converted to IU in 1000ml diluent. One IU corresponded to 1.67μg for doses provided in grams/micrograms. IU hourly dose increase rates were based on escalation frequency. Cumulative doses and total IU amount infused were calculated by adding the dose administered for each previous hour. Main Outcome Measures Oxytocin IU dose infused.
RESULTS
Data were obtained on 21 regimens used in 12 countries. Details on the start dose, escalation interval, escalation rate and maximum dose infused were available from 16 regimens. Starting rates varied from 0.06 IU/hour to 0.90 IU/hour, and the maximum dose rate varied from 0.90 IU/hour to 3.60 IU/hour. The total amount of IU oxytocin infused, estimated over eight hours, ranged from 2.38 IU to 27.00 IU, a variation of 24.62 IU and an 11-fold difference.
CONCLUSION
Current variations in oxytocin regimens for induction and augmentation of labour are inexplicable. It is crucial that the appropriate minimum infusion regimen is administered because synthetic oxytocin is a potentially harmful medication with serious consequences for women and babies when inappropriately used. Estimating the total amount of oxytocin IU received by labouring women, alongside the institution's mode of birth and neonatal outcomes, may deepen our understanding and be the way forward to identifying the optimal infusion regimen.
Topics: Drug Administration Schedule; Europe; Female; Humans; Labor, Induced; Labor, Obstetric; Oxytocics; Oxytocin; Practice Guidelines as Topic; Pregnancy
PubMed: 32722667
DOI: 10.1371/journal.pone.0227941 -
The Cochrane Database of Systematic... Apr 2015Hysteroscopy is an operation in which the gynaecologist examines the uterine cavity using a small telescopic instrument (hysteroscope) inserted via the vagina and the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Hysteroscopy is an operation in which the gynaecologist examines the uterine cavity using a small telescopic instrument (hysteroscope) inserted via the vagina and the cervix. Almost 50% of hysteroscopic complications are related to difficulty with cervical entry. Potential complications include cervical tears, creation of a false passage, perforation, bleeding, or simply difficulty in entering the internal os (between the cervix and the uterus) with the hysteroscope. These complications may possibly be reduced with adequate preparation of the cervix (cervical ripening) prior to hysteroscopy. Cervical ripening agents include oral or vaginal prostaglandin, which can be synthetic (e.g misoprostol) or natural (e.g. dinoprostone) and vaginal osmotic dilators, which can be naturally occurring (e.g. laminaria) or synthetic.
OBJECTIVES
To determine whether preoperative cervical preparation facilitates cervical dilatation and reduces the complications of operative hysteroscopy in women undergoing the procedure for any condition.
SEARCH METHODS
In August 2014 we searched sources including the Menstrual Disorders and Subfertility Group (MDSG) Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, ClinicalTrials.gov and reference lists of relevant articles. We searched for published and unpublished studies in any language.
SELECTION CRITERIA
Two review authors independently selected randomised controlled trials (RCTs) of cervical ripening agents used before operative hysteroscopy in pre- and postmenopausal women. Cervical ripening agents could be compared to each other, placebo or no treatment.
DATA COLLECTION AND ANALYSIS
Data extraction and quality assessment were conducted independently by two review authors. The primary review outcomes were effectiveness of cervical dilatation (defined as the proportion of women requiring mechanical cervical dilatation) and intraoperative complications. Secondary outcomes were mean time required to dilate the cervix, preoperative pain, cervical width, abandonment of the procedure, side effects of dilating agents and duration of surgery. We calculated odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, with 95% confidence intervals ( CIs). Data were statistically pooled where appropriate. Heterogeneity was assessed using the I(2) statistic. The overall quality of the evidence was assessed using GRADE methods.
MAIN RESULTS
Nineteen RCTs with a total of 1870 participants were included. They compared misoprostol with no treatment or placebo, dinoprostone or osmotic dilators.Misoprostol was more effective for cervical dilatation than placebo or no intervention, with fewer women requiring mechanical dilatation (OR 0.08, 95% CI 0.04 to 0.16, five RCTs, 441 participants, I(2)=0%, moderate quality evidence). This suggests that in a population in which 80% of women undergoing hysteroscopy require mechanical dilatation without use of preoperative ripening agents, use of misoprostol will reduce the need for mechanical dilatation to between 14% and 39%. Misoprostol was associated with fewer intraoperative complications (OR 0.37, 95% CI 0.18 to 0.77, 12 RCTs, 901 participants, I(2)=0%, moderate quality evidence). This suggests that in a population in which 3% of women undergoing hysteroscopy experience intraoperative complications without use of preoperative ripening agents, use of misoprostol will reduce the risk of complications to 2% or less.When specific complications were considered, the misoprostol group had a lower rate of cervical laceration or tearing (OR 0.25, 95% CI 0.11 to 0.57, nine RCTS, 669 women, I(2)=0%, moderate quality evidence) or false track formation (OR 0.34, 95% CI 0.12 to 0.97, seven RCTs, 560 participants, I(2)=0%, moderate quality evidence). There was no evidence of a difference between the groups in rates of uterine perforation (0.42, 95% CI 0.13 to 1.38, seven RCTs, 455 participants, I(2)=0%, low quality evidence) or uterine bleeding (OR 0.51, 95% CI 0.10 to 2.49, four RCTs, 340 participants, I(2)=0%, low quality evidence). Some treatment side effects (mild abdominal pain, vaginal bleeding, and increased body temperature) were more common in the misoprostol group.Compared with dinoprostone, misoprostol was associated with more effective cervical dilatation, with fewer women requiring mechanical dilatation (OR 0.58; 95% CI 0.34 to 0.98; one RCT, 310 participants, low quality evidence) and with fewer intraoperative complications (OR 0.32; 95% CI 0.12 to 0.83, one RCT, 310 participants, low quality evidence). However treatment side effects were more common in the misoprostol arm.Compared to osmotic dilatation (laminaria), misoprostol was associated with less effective cervical dilatation, with more women in the misoprostol group requiring mechanical dilatation (OR 5.96, 95% CI 2.61 to 13.59, one RCT, 110 participants, low quality evidence). There was no evidence of a difference between misoprostol and osmotic dilators in intraoperative complication rates (OR 5.14, 95% CI 0.24 to 109.01, three RCTs, 354 participants, low quality evidence), with only two events reported altogether.The overall quality of the evidence ranged from low to moderate. The main limitations in the evidence were imprecision and poor reporting of study methods.
AUTHORS' CONCLUSIONS
There is moderate quality evidence that use of misoprostol for preoperative ripening of the cervix before operative hysteroscopy is more effective than placebo or no treatment and is associated with fewer intraoperative complications such as lacerations and false tracks. However misoprostol is associated with more side effects, including preoperative pain and vaginal bleeding. There is low quality evidence to suggest that misoprostol has fewer intraoperative complications and is more effective than dinoprostone.There is also low quality evidence to suggest that laminaria may be more effective than misoprostol, with uncertain effects for complication rates. However the possible benefits of laminaria need to be weighed against the inconvenience of its insertion and retention for one to two days.
Topics: Cervical Ripening; Cervix Uteri; Dilatation; Dinoprostone; Female; Humans; Hysteroscopy; Laminaria; Misoprostol; Oxytocics; Pregnancy; Preoperative Care; Randomized Controlled Trials as Topic
PubMed: 25906113
DOI: 10.1002/14651858.CD005998.pub2 -
BMJ (Clinical Research Ed.) Jul 2015
Review
Topics: Developing Countries; Evidence-Based Medicine; Female; Health Resources; Humans; Labor Stage, Third; Oxytocics; Postpartum Hemorrhage; Practice Guidelines as Topic; Pregnancy; Randomized Controlled Trials as Topic; Risk Factors
PubMed: 26156874
DOI: 10.1136/bmj.h3251 -
The Cochrane Database of Systematic... Jan 2015Active management of the third stage of labour (AMTSL) consists of a group of interventions, including administration of a prophylactic uterotonic (at at or after... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Active management of the third stage of labour (AMTSL) consists of a group of interventions, including administration of a prophylactic uterotonic (at at or after delivery of the baby), baby, cord clamping and cutting, controlled cord traction (CCT) to deliver the placenta, and uterine massage. Recent recommendations are to delay cord clamping until the caregiver is ready to initiate CCT. The package of AMTSL reduces the risk of postpartum haemorrhage, (PPH), as does one component, routine use of uterotonics. The contribution, if any, of CCT needs to be quantified, as it is uncomfortable, and women may prefer a 'hands-off' approach. In addition its implementation has resource implications in terms of training of healthcare providers.
OBJECTIVES
To evaluate the effects of controlled cord traction during the third stage of labour, either with or without conventional active management.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (29 January 2014), PubMed (1966 to 29 January 2014), and reference lists of retrieved studies.
SELECTION CRITERIA
Randomised controlled trials comparing planned CCT versus no planned CCT in women giving birth vaginally.
DATA COLLECTION AND ANALYSIS
Two authors assessed trial quality and extracted data using a standard data extraction form.
MAIN RESULTS
We included three methodologically sound trials with data on 199, 4058 and 23,616 women respectively. Blinding was not possible, but bias could be limited by the fact that blood loss was measured objectively.There was no difference in the risk of blood loss ≥ 1000 mL (three trials, 27,454 women; risk ratio (RR) 0.91, 95% confidence interval (CI) 0.77 to 1.08). Manual removal of the placenta was reduced with CCT (two trials, 27,665 women; RR 0.69, 95% CI 0.57 to 0.83). In the World Health Organization (WHO) trial the reduction in manual removal occurred mainly in sites where ergometrine was used routinely in the third stage of labour. The non-prespecified analysis excluding sites routinely using ergometrine for management of the third stage of labour found no difference in the risk of manual removal of the placenta in the WHO trial (one trial, 23,010 women; RR 1.03, 95% CI 0.73 to 1.46). The policy of restricting the third stage of labour to 30 minutes (4057 women; RR 0.69, 95% CI 0.53 to 0.90) may have had an effect in the French study.Among the secondary outcomes, there were reductions in blood loss ≥ 500 mL (three trials, 27,454 women; RR 0.93, 95% CI 0.88 to 0.99), mean blood loss (two trials, 27,255 women; mean difference (MD) -10.85 mL, 95% CI -16.73 to -4.98), and duration of the third stage of labour (two trials, 27,360 women; standardised MD -0.57, -0.59 to -0.54). There were no clear differences in use of additional uterotonics (three trials, 27,829 women; average RR 0.95, 95% CI 0.88 to 1.02), blood transfusion, maternal death/severe morbidity, operative procedures nor maternal satisfaction. Maternal pain (non-prespecified) was reduced in one trial (3760 women; RR 0.78, 95% CI 0.61 to 0.99).The following secondary outcomes were not reported upon in any of the trials: retained placenta for more than 60 minutes or as defined by trial author; maternal haemoglobin less than 9 g/dL at 24 to 48 hours post-delivery or blood transfusion; organ failure; intensive care unit admission; caregiver satisfaction; cost-effectiveness; evacuation of retained products; or infection.
AUTHORS' CONCLUSIONS
CCT has the advantage of reducing the risk of manual removal of the placenta in some circumstances, and evidence suggests that CCT can be routinely offered during the third stage of labour, provided the birth attendant has the necessary skills. CCT should remain a core competence of skilled birth attendants. However, the limited benefits of CCT in terms of severe PPH would not justify the major investment which would be needed to provide training in CCT skills for birth attendants who do not have formal training. Women who prefer a less interventional approach to management of the third stage of labour can be reassured that when a uterotonic agent is used, routine use of CCT can be omitted from the 'active management' package without increased risk of severe PPH, but that the risk of manual removal of the placenta may be increased.Research gaps include the use of CCT in the absence of a uterotonic, and the place of uterine massage in the management of the third stage of labour.
Topics: Constriction; Ergonovine; Extraction, Obstetrical; Female; Humans; Labor Stage, Third; Oxytocics; Placenta; Postpartum Hemorrhage; Pregnancy; Randomized Controlled Trials as Topic; Umbilical Cord
PubMed: 25631379
DOI: 10.1002/14651858.CD008020.pub2 -
BMC Pregnancy and Childbirth Feb 2018Active management of the third stage of labor (AMTSL) describes interventions with the common goal to prevent postpartum hemorrhage (PPH). In low- and middle-income... (Review)
Review
BACKGROUND
Active management of the third stage of labor (AMTSL) describes interventions with the common goal to prevent postpartum hemorrhage (PPH). In low- and middle-income countries, implementation of AMTSL is hampered by shortage of skilled birth attendants and a high percentage of home deliveries. Task shifting of specific AMTSL components to unskilled birth attendants or self-administration could be a strategy to increase access to potentially life-saving interventions. This study was designed to evaluate the effect, acceptance and safety of task shifting of specific aspects of AMTSL to unskilled birth attendants.
METHODS
A systematic search was conducted in five databases in September 2015 to identify intervention studies of AMTSL implemented by unskilled birth attendants or pregnant women themselves. Quality of studies was evaluated with an adapted Cochrane Collaboration assessment tool.
RESULTS
Of 2469 studies screened, 21 were included. All studies assessed implementation of uterotonics (misoprostol tablets or oxytocin injections), administered by community health workers (CHWs), auxiliary midwives, traditional birth attendants (TBAs) or self-administration at antenatal (home) visits or delivery. Task shifting for none of the other AMTSL components was reported. Task shifting of provision of uterotonics reduced the risk of PPH (RR 0.16 to 1) compared to standard care (13 studies, n = 15.197). The correct dose and timing was reported for 83.4 to 99.8% (5 studies, n = 6083) and 63 to 100% (9 studies, n = 8378) women respectively. Uterotonics were recommended to others by 80 to 99.7% (7 studies, n = 6445); 80 to 99.4% (5 studies, n = 2677) would use the drug at next delivery. Willingness to pay for uterotonics varied from 54.6 to 100% (7 studies, n = 6090).
CONCLUSION
Task shifting of AMTSL has thus far been evaluated for administration of uterotonics (misoprostol tablets and oxytocin injected by CHWs and auxiliary midwives) and resulted in reduction of PPH, high rates of appropriate use and satisfaction among users. In order to increase AMTSL coverage in low-staffed health facilities, task shifting of uterine massage or postpartum tonus assessment to unskilled attendants or delivered women could be considered. Task shifting of controlled cord traction is currently not recommended.
Topics: Adult; Community Health Workers; Delivery, Obstetric; Female; Humans; Labor Stage, Third; Maternal Health Services; Midwifery; Oxytocics; Patient Acceptance of Health Care; Postpartum Hemorrhage; Pregnancy; Young Adult
PubMed: 29409456
DOI: 10.1186/s12884-018-1677-5 -
Midwifery Sep 2014to identify primary and secondary outcome measures in randomised trials, and systematic reviews of randomised trials, measuring effectiveness of oxytocin for treatment... (Review)
Review
OBJECTIVES
to identify primary and secondary outcome measures in randomised trials, and systematic reviews of randomised trials, measuring effectiveness of oxytocin for treatment of delay in the first and second stages of labour, and to identify any positive health-focussed outcomes used.
DESIGN
eight relevant citation databases were searched up to January 2013 for all randomised trials, and systematic reviews of randomised trials, measuring effectiveness of oxytocin for treatment of delay in labour. Trials of active management of labour or partogram action lines were excluded. 1918 citations were identified. Two reviewers reviewed all citations and extracted data. Twenty-six individual trials and five systematic reviews were included. Primary and secondary outcome measures were documented and analysed using frequency distributions.
FINDINGS
most frequent primary outcomes were caesarean section (n=15, 46%), length of labour (n=14, 42%), measurements of uterine activity (n=13, 39%) and mode of vaginal birth (n=9, 27%). Maternal satisfaction was identified a priori by one review and included as a secondary outcome by three papers. No further positive health-focussed outcomes were identified.
KEY CONCLUSIONS
outcomes used to measure the effectiveness of oxytocin for treatment of delay in labour are heterogeneous and tend to focus on adverse events.
IMPLICATIONS FOR PRACTICE
it is recommended that, in future randomised trials of oxytocin use for delay in labour, some women-centred and health-focussed outcome measures should be used, which may instil a more salutogenic culture in childbirth.
Topics: Cesarean Section; Delivery, Obstetric; Female; Humans; Obstetric Labor Complications; Oxytocics; Oxytocin; Pregnancy; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 25017174
DOI: 10.1016/j.midw.2014.06.005 -
The Cochrane Database of Systematic... Oct 2014When women require induction of labour, oxytocin is the most common agent used, delivered by an intravenous infusion titrated to uterine contraction strength and... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Female; Humans; Labor, Induced; Oxytocics; Oxytocin; Pregnancy; Randomized Controlled Trials as Topic; Term Birth
PubMed: 25300173
DOI: 10.1002/14651858.CD009701.pub2