The use and abuse of oxytocin

Continuation versus discontinuation of intravenous oxytocin in the active phase of labour

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects of discontinuing intravenous oxytocin stimulation in pregnant women during the active phase of induced or augmented labour.

Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): individual management based on artificial intelligence - a secondary analysis

BACKGROUND

Current guidelines regarding oxytocin stimulation are not tailored to individuals as they are based on randomised controlled trials. The objective of the study was to develop an artificial intelligence (AI) model for individual prediction of the risk of caesarean delivery (CD) in women with a cervical dilatation of 6 cm after oxytocin stimulation for induced labour. The model included not only variables known when labour induction was initiated but also variables describing the course of the labour induction.

METHODS

Secondary analysis of data from the CONDISOX randomised controlled trial of discontinued vs. continued oxytocin infusion in the active phase of induced labour. Extreme gradient boosting (XGBoost) software was used to build the prediction model. To explain the impact of the predictors, we calculated Shapley additive explanation (SHAP) values and present a summary SHAP plot. A force plot was used to explain specifics about an individual's predictors that result in a change of the individual's risk output value from the population-based risk.

RESULTS

Among 1060 included women, 160 (15.1%) were delivered by CD. The XGBoost model found women who delivered vaginally were more likely to be parous, taller, to have a lower estimated birth weight, and to be stimulated with a lower amount of oxytocin. In 108 women (10% of 1060) the model favoured either continuation or discontinuation of oxytocin. For the remaining 90% of the women, the model found that continuation or discontinuation of oxytocin stimulation affected the risk difference of CD by less than 5% points.

CONCLUSION

In women undergoing labour induction, this AI model based on a secondary analysis of data from the CONDISOX trial may help predict the risk of CD and assist the mother and clinician in individual tailored management of oxytocin stimulation after reaching 6 cm of cervical dilation.

Continued versus discontinued oxytocin after the active phase of labor: An updated systematic review and meta-analysis

Objective

To systematically assess the effect of discontinued vs continued oxytocin after active stage of labour is established.

Methods

Pubmed, Embase, and the Cochrane Library were systematically searched to 18 April 2021. The risk ratio or mean difference with corresponding 95% confidence interval were computed to investigate the effect of intervention or control on maternal and fetus outcomes. This review was registered in the International Prospective Register of Systematic Reviews: CRD42021249635.

Results

Discontinuing oxytocin when the active labour was established might decrease the risk of cesarean delivery [RR (95% CI): 0.84 (0.72–0.98), P = 0.02]. However, when we restricted our analysis to women who performed cesarean section after the active phase was reached, the difference was no longer significant [RR (95% CI): 0.82 (0.60–1.10), P = 0.19]. The incidence of uterine tachysystole [RR (95% CI): 0.36 (0.27–0.49)], postpartum hemorrhage [RR (95% CI): 0.78 (0.65–0.93)], and non-reassuring fetal heart rate [RR (95% CI): 0.66 (0.58–0.76)] were significantly lower in the oxytocin discontinuation group. We also found a possible decrease in the risk of chorioamnionitis in discontinued oxytocin group [RR (95% CI): 2.77 (1.02–5.08)]. An increased duration of active [MD (95% CI): 2.28 (2.86–41.71)] and second [MD (95% CI): 5.36 (3.18–7.54)] phase of labour was observed in discontinued oxytocin group, while the total delivery time was not significantly different [MD (95% CI): 20.17 (-24.92–65.26)].

Conclusion

After the active labor is reached, discontinuation of oxytocin could be considered a new recommendation for the improved maternal and fetal outcomes without delaying labour.

Oxytocin and Related Peptide Hormones: Candidate Anti-Inflammatory Therapy in Early Stages of Sepsis

Sepsis is a potentially life-threatening systemic inflammatory syndrome characterized by dysregulated host immunological responses to infection. Uncontrolled immune cell activation and exponential elevation in circulating cytokines can lead to sepsis, septic shock, multiple organ dysfunction syndrome, and death. Sepsis is associated with high re-hospitalization and recovery may be incomplete, with long term sequelae including post-sepsis syndrome. Consequently, sepsis continues to be a leading cause of morbidity and mortality across the world. In our recent review of human chorionic gonadotropin (hCG), we noted that its major properties including promotion of fertility, parturition, and lactation were described over a century ago. By contrast, the anti-inflammatory properties of this hormone have been recognized only more recently. Vasopressin, a hormone best known for its anti-diuretic effect, also has anti-inflammatory actions. Surprisingly, vasopressin's close cousin, oxytocin, has broader and more potent anti-inflammatory effects than vasopressin and a larger number of pre-clinical studies supporting its potential role in limiting sepsis-associated organ damage. This review explores possible links between oxytocin and related octapeptide hormones and sepsis-related modulation of pro-inflammatory and anti-inflammatory activities.

Barriers to optimal and appropriate use of uterotonics during active labour and for prevention of postpartum haemorrhage in public health care facilities: An exploratory study in five states of India

OBJECTIVE

The main objective is to understand the practices regarding use of uterotonics during active labour and for prevention of postpartum haemorrhage and the barriers for its optimal and appropriate use at different levels of health facilities in five states of India.

STUDY DESIGN

Mixed methods approach comprising of cross-sectional observational study of existing practices of uterotonics use during labour and early postpartum period for 1479 vaginal deliveries at 56 facilities. Quantitative data was collected using pre-tested proformas filled by on-site observers and qualitative data was collected by in-depth interviews of 125 maternity care providers of the observed facilities.

MAIN OUTCOME MEASURE

Providers' knowledge, attitude and patterns of use of uterotonics during active labour and for prevention of postpartum haemorrhage during childbirth.

RESULTS

On-site observation and interviews indicated inappropriate choice of uterotonics administered in varied doses for labour management across facilities. Unnecessary augmentation of labour was observed in 44.7% low-risk pregnancies and only 31% women were administered uterotonics in optimal doses for preventing postpartum haemorrhage. Only 46.4% providers in the observed facilities reported to have received maternal and child healthcare training according to the updated guidelines. Lack of supportive supervision for mandated practices among peers emerged as an important barrier for appropriate uterotonics usage in labour.

CONCLUSION

There is an urgent scope of standardizing the institutional health policies regarding administration of uterotonics during labour and for prevention of postpartum haemorrhage. Capacity building of maternity care providers regarding appropriate uterotonics usage is recommended for all levels of health facilities.

Continued versus discontinued oxytocin stimulation in the active phase of labour (CONDISOX): double blind randomised controlled trial

OBJECTIVE

To determine whether discontinuing oxytocin stimulation in the active phase of induced labour is associated with lower caesarean section rates.

DESIGN

International multicentre, double blind, randomised controlled trial.

SETTING

Nine hospitals in Denmark and one in the Netherlands between 8 April 2016 and 30 June 2020.

PARTICIPANTS

1200 women stimulated with intravenous oxytocin infusion during the latent phase of induced labour.

INTERVENTION

Women were randomly assigned to have their oxytocin stimulation discontinued or continued in the active phase of labour.

MAIN OUTCOME MEASURE

Delivery by caesarean section.

RESULTS

A total of 607 women were assigned to discontinuation and 593 to continuation of the oxytocin infusion. The rates of caesarean section were 16.6% (n=101) in the discontinued group and 14.2% (n=84) in the continued group (relative risk 1.17, 95% confidence interval 0.90 to 1.53). In 94 parous women with no previous caesarean section, the caesarean section rate was 7.5% (11/147) in the discontinued group and 0.6% (1/155)in the continued group (relative risk 11.6, 1.15 to 88.7). Discontinuation was associated with longer duration of labour (median from randomisation to delivery 282 v 201 min; P<0.001), a reduced risk of hyperstimulation (20/546 (3.7%) v 70/541 (12.9%); P<0.001), and a reduced risk of fetal heart rate abnormalities (153/548 (27.9%) v 219/537 (40.8%); P<0.001) but rates of other adverse maternal and neonatal outcomes were similar between groups.

CONCLUSIONS

In a setting where monitoring of the fetal condition and the uterine contractions can be guaranteed, routine discontinuation of oxytocin stimulation may lead to a small increase in caesarean section rate but a significantly reduced risk of uterine hyperstimulation and abnormal fetal heart rate patterns.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02553226.

Prevalence of use of highly concentrated oxytocin or "pepper injection" in labor among clinicians undergoing emergency obstetric training in Sierra Leone

OBJECTIVE

To examine the awareness, prevalence of use, and knowledge of risks of pepper injection (PI), an injection of highly concentrated oxytocin used to augment or induce labor, among clinicians.

METHODS

An anonymous pre- and post-workshop evaluation conducted among 227 clinicians participating in emergency obstetric and newborn care training in Sierra Leone from June to October 2018.

RESULTS

Overall, 225 participants completed the surveys. Of these, 198 (88.0%) of clinicians reported awareness of PI, and 123 (54.7%) self-reported prior use, which was highest among midwives (94/129; 72.9%). Before EmONC training, 82 (36.4%) clinicians reported that they were likely to use PI; this decreased to 39 (17.3%) after training (P<0.05). The mean number of participants correctly identifying risks of PI increased from 149 (66.2%) to 204 (90.7%) after training (P<0.05).

CONCLUSION

There was widespread awareness of PI use among clinicians, and prevalent self-reported prior use among midwives. Risk awareness improved after EmONC training, and the proportion of clinicians reporting likelihood of future use decreased. Improper use of oxytocin may be a major contributor to maternal and newborn morbidity and mortality in Sierra Leone. Initiatives to educate clinicians and to regulate and stop the practice are needed.

Uterine Activity Impacts Fetal and Neonatal Outcomes

Uterine activity impacts fetal and neonatal outcomes. The value of analysis of contraction frequency and the duration of the resting interval were underappreciated until the last two decades. Misconceptions about electronic fetal monitoring and the cesarean section rate may be related to the lack of early research on the significant impact of abnormal uterine activity.

How much synthetic oxytocin is infused during labour? A review and analysis of regimens used in 12 countries

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.

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.

PROM and Labour Effects on Urinary Metabolome: A Pilot Study

Since pathologies and complications occurring during pregnancy and/or during labour may cause adverse outcomes for both newborns and mothers, there is a growing interest in metabolomic applications on pregnancy investigation. In fact, metabolomics has proved to be an efficient strategy for the description of several perinatal conditions. In particular, this study focuses on premature rupture of membranes (PROM) in pregnancy at term. For this project, urine samples were collected at three different clinical conditions: out of labour before PROM occurrence (Ph1), out of labour with PROM (Ph2), and during labour with PROM (Ph3). GC-MS analysis, followed by univariate and multivariate statistical analysis, was able to discriminate among the different classes, highlighting the metabolites most involved in the discrimination.

A randomised double-blind placebo-controlled trial comparing stepwise oral misoprostol with vaginal misoprostol for induction of labour

A comparison of induction of labour (IOL) using three doses of 25 µg vaginal misoprostol inserted at intervals of 4 h or more with a stepwise oral regime starting with 50 µg followed by two doses of 100 µg was studied in a double-blind placebo-controlled trial in a tertiary centre in South India. Primary outcome was vaginal delivery in 24 h. Significantly more women in the first group required oxytocin augmentation and a third dose of the drug than women in the second group. Uterine tachysystole and other maternal and neonatal complications were similar. Thus it is concluded that women induced with oral, as compared to vaginal misoprostol are more likely to labour without oxytocin.