High-dose vs low-dose oxytocin for labor augmentation: a systematic review

Clinical management of uterine contraction abnormalities; an evidence-based intrapartum care algorithm

AIM

To develop algorithms as decision support tools for identifying, managing and monitoring abnormal uterine activity during labour.

POPULATION

Women with singleton, term (37-42 weeks) pregnancies in active labour at admission.

SETTING

Institutional birth settings in low- and middle-income countries (the algorithm may be applicable to any health facility).

SEARCH STRATEGY

PubMed was searched up to January 2020 using keywords. We also searched The Cochrane Library, and international guidelines from World Health Organization (WHO), National Institute for Health and Care Excellence (NICE), American College of Obstetricians and Gynecologists (ACOG) and French College of Gynaecologists and Obstetricians (CNGOF).

CASE SCENARIOS

Algorithms were developed for two case scenarios: uterine hypoactivity and excessive uterine contractions. Key themes in the algorithm are: diagnosis, identification of probable causes, assessment of maternal and fetal condition and labour progress, monitoring and management.

CONCLUSION

The algorithms for uterine hypoactivity and excessive uterine contractions have been developed to facilitate safe and effective management of abnormal uterine activity during labour. Research is needed to assess the views of healthcare professionals and women accessing healthcare to explore the feasibility of implementing these algorithms, and impact on labour outcomes.

TWEETABLE ABSTRACT

An evidence-based algorithm to support clinical management of abnormal uterine activity during labour.

Endorphins, Sexuality, and Reproduction

Beta-endorphin is secreted from the hypothalamus and pituitary in both mother and newborn. The placenta produces numerous pituitary hormones from the third month of pregnancy, one of which is βE. It has been suggested that βE has a role in the appetitive and precopulatory phase of sexual behavior in animals. An increase in endorphin levels during sexual activity in humans may contribute to attachment and bonding between partners, but contradictory reports in the literature question the association between sexuality and βE levels. The level of βE also increases during pregnancy, rises in early labor, peaks in late labor, and drops in the postpartum period. This fluctuation provides natural analgesia, raises the pain threshold, decreases the sensation of pain, or suppresses pain, and decreases fear levels during labor and birth. Beta-endorphin also protects the fetus from hypoxia during labor and birth and potential neural damage by aiding blood flow to the brain under hypoxic conditions. It has been suggested that a variety of pharmacologic and nonpharmacologic complementary therapies, when used in pregnancy, labor, and birth, activate the opioid receptors in the CNS and alter the sensation of pain during labor and birth, affect the mother-child attachment and affect sexual function. These studies report contradictory results that will be discussed in this chapter.

Effects of oxytocin induction on early postpartum hemorrhage, perineal integrity, and breastfeeding: a case-control study

OBJECTIVE

The aim of this study was to evaluate the postpartum hemorrhage, perineal integrity, and breastfeeding results of mothers who underwent oxytocin induction in the first stage of labor in the early postpartum period.

METHODS

This single-center observational case-control study was conducted in the obstetric unit of a public hospital in Istanbul. The study sampling included 44 pregnant women who received oxytocin induction (case group) and 44 pregnant women who did not receive oxytocin (control group). The Personal Information Form, LATCH Breastfeeding Assessment Tool, Breastfeeding Self-Efficacy Scale, Redness, Edema, Ecchymosis, Discharge, and Approximation Scale, and Postpartum Hemorrhage Collection Bag were used in data collection, and pad follow-up was carried out.

RESULTS

The amount of hemorrhage in the first 24 h of the postpartum period and the mean Redness, Edema, Ecchymosis, Discharge, and Approximation Scale score were significantly higher in the case group. While 47.7% of the oxytocin-induced women had 1st or 2nd, and 11.4% had 3rd or 4th degrees of lacerations, 20.5% of the control group had 1st or 2nd, and 2.3% had 3rd or 4th degrees of lacerations. There was no significant difference between the mean scores of the Breastfeeding Self-Efficacy Scale and LATCH Breastfeeding Assessment Tool in both groups.

CONCLUSION

According to the study findings, it was determined that oxytocin induction administered in the first stage of labor increased hemorrhage and perineal trauma in the early postpartum period but did not affect the results of breastfeeding.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04441125.

Accurate evaluation of the progress of delivery with transperineal ultrasound may improve vaginal delivery: a single-center retrospective study

Although digital examination of the cervix is the standard method used worldwide for evaluating the progress of delivery, it is subjective. Transperineal ultrasound (TPU) is combined with digital evaluation for accurate assessment of fetal descent and rotation of the advanced part of the fetus. This retrospective study aimed to clarify the impact of introducing TPU on perinatal outcomes at Mie University Hospital. We analyzed singleton pregnant women who underwent delivery management at our hospital between April 2020 and March 2021. Perinatal outcomes were compared between patients who used TPU (TPU+ group) and those who did not (TPU- group). The angle of progression and head direction were measured. The rate of vaginal delivery was significantly increased (90.9% vs. 71.6%; P = 0.0017), and the second stage of labor was significantly prolonged in the TPU+ group (148.1 vs. 75.8 min; P < 0.0001). A significant difference was observed in termination in the latent phase between the TPU+ group [3/8 (37.5%) cases] and TPU- group [20/25 (80.0%) cases] (P = 0.036). The rate of vaginal delivery can be increased through accurate evaluation of the progress of delivery with TPU.

Vaginal Birth at Term - Part 2. Guideline of the DGGG, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/083, December 2020)

Purpose This guideline aims to summarize the current state of knowledge about vaginal birth at term. The guideline focuses on definitions of the physiological stages of labor as well as differentiating between various pathological developments and conditions. It also assesses the need for intervention and the options to avoid interventions. The second part of this guideline presents recommendations and statements on care during the dilation and expulsion stages as well as during the placental/postnatal stage. Methods The German recommendations largely reproduce the recommendations of the National Institute for Health and Care Excellence (NICE) CG190 guideline "Intrapartum care for healthy women and babies". Other international guidelines were also consulted in individual cases when compiling this guideline. In addition, a systematic search and analysis of the literature was carried out using PICO questions where necessary, and other systematic reviews and individual studies were taken into account. For easier comprehension, the assessment tools of the Scottish Intercollegiate Guidelines Network (SIGN) were used to evaluate the quality of additionally consulted studies. Otherwise, the GRADE system was used for the NICE guideline, and the evidence reports of the IQWiG were used to evaluate the quality of the evidence. Recommendations Recommendations and statements were formulated based on identified evidence and/or a structured consensus.

European Guidelines on Perinatal Care - Oxytocin for induction and augmentation of labor[Formula: see text]

OF RECOMMENDATIONS1. Oxytocin for induction or augmentation of labor should not be started when there is a previous scar on the body of the uterus (such as previous classical cesarean section, uterine perforation or myomectomy when uterine cavity is reached) or in any other condition where labor or vaginal delivery are contraindicated. (Moderate quality evidence +++-; Strong recommendation).2. Oxytocin should not be started before at least 1 h has elapsed since amniotomy, 6 h since the use of dinoprostone (30 min if vaginal insert) and 4 h since the use of misoprostol (Low quality evidence ++- -; Moderate recommendation).3. Cardiotocography (CTG) should be performed and a normal pattern without tachysystole should be documented for at least 30 min before oxytocin is used. Continuous CTG, with adequate monitoring of both fetal heart rate and uterine contractions, should be maintained for as long as oxytocin is used, and thereafter until delivery (Low ++- - to moderate +++- quality evidence; Strong recommendation).4. For labor induction, at least 1-h should be allowed after amniotomy before oxytocin infusion is started, to evaluate whether adequate uterine contractility has meanwhile ensued. For augmentation of labor, if the membranes are intact and there are conditions for a safe amniotomy, the latter should be considered before oxytocin is started (Very low quality evidence +- --; Weak recommendation).5. Oxytocin should be administered intravenously using the following regimen: 5 IU oxytocin diluted in 500 mL of 0.9% normal saline (NaCl) (each mL contains 10 mIU of oxytocin), in an infusion pump at increasing rates, as shown in Table 1, until a frequency of 3-4 contractions per 10 min is reached, a non-reassuring CTG pattern ensues, or maximum rates are reached (Low quality evidence ++ - -; Strong recommendation). If the frequency of contractions exceeds 5 in 10 min, the infusion rate should be reduced, even if a normal CTG pattern is present. With a non-reassuring CTG pattern, urgent clinical assessment by an obstetrician is indicated, and strong consideration should be given to reducing or stopping the oxytocin infusion. The minimal effective dose of oxytocin should always be used. (Low ++- - to Moderate +++- - quality evidence; Strong recommendation).[Table: see text]6. Use of oxytocin for induction and augmentation of labor should be regularly audited (Low quality evidence ++--; Strong recommendation).

Perinatal outcomes of high dose versus low dose oxytocin regimen used for labor induction and factors associated with adverse perinatal outcome in four hospitals of Ethiopia: a multicenter comparative study

BACKGROUND

There is limited evidence on effect of high and low dose oxytocin used for labor induction on perinatal outcomes. We compared perinatal outcomes among pregnant mothers who received the two different oxytocin regimens and identified risk factors associated with adverse perinatal outcomes.

METHODS

Facility based comparative cross-sectional study was conducted in four hospitals of Ethiopia over eight month's period during 2017/2018 year with 216 pregnant women who received high and low dose oxytocin for labor induction. Socio-demographics, reproductive characteristics of mothers and perinatal outcomes data were collected and entered into Epi-data version 3.1 and then exported to SPSS version 20 for cleaning and analysis. Chi-square test and logistic regression were done to see the effect of different oxytocin regimens on perinatal outcome. The result was presented using 95 % confidence interval of crude and adjusted odds ratios. P-value < 0.05 was used to declare statistical significance.

RESULT

Higher adverse perinatal outcomes (29 % vs. 13.9 %, p = 0.005) and higher non-reassuring fetal heart rate pattern (23.1 % vs. 7.4 %, p = 0.001) was observed among mothers who received high dose oxytocin compared to mothers who received low dose oxytocin. Using high oxytocin dose [AOR = 2.4, 95 % CI: 1.1, 5.5], caesarean birth [AOR = 9.3, 95 %CI: 3.8, 22.5], instrumental birth [AOR = 7.7, 95 % CI: 2.1, 27.8], and antepartum hemorrhage [AOR = 17.8, 95 %CI: 1.9, 168.7] were risk factors of adverse perinatal outcomes.

CONCLUSIONS

There was significance difference in the occurrence of adverse perinatal outcomes among pregnant mothers who received high and low dose of oxytocin. Using high dose oxytocin, antepartum hemorrhage, caesarean birth and instrumental birth were associated with increased risk of adverse perinatal outcomes. We recommend using low dose oxytocin for better perinatal outcomes.

The Comprehensive Neural Mechanism of Oxytocin in Analgesia

Oxytocin (OXT) is a nine amino acid neuropeptide hormone that has become one of the most intensively studied molecules in the past few decades. The vast majority of OXT is synthesized in the periventricular nucleus and supraoptic nucleus of the hypothalamus, and a few are synthesized in some peripheral organs (such as the uterus, ovaries, adrenal glands, thymus, pancreas, etc.) OXT modulates a series of physiological processes, including lactation, parturition, as well as some social behaviors. In addition, more and more attention has recently been focused on the analgesic effects of oxytocin. It has been reported that OXT can relieve tension and pain without other adverse effects. However, the critical role and detailed mechanism of OXT in analgesia remain unclear. This review aims to summarize the mechanism of OXT in analgesia and some ideas about the mechanism.

High dose vs. low dose oxytocin for labor augmentation: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare the safety and efficacy between high dose and low dose oxytocin administration for labor augmentation.

METHODS

We searched for the available studies during March 2020 in PubMed, Cochrane Library, Scopus, and ISI Web of science. All randomized clinical trials (RCTs) that assessed safety and efficacy of high dose vs. low dose oxytocin for labor augmentation were considered. The extracted data were entered into RevMan software. Dichotomous and continuous data were pooled as odds ratio (OR) and mean difference (MD) respectively, with the corresponding 95% confidence intervals (CI). Our main outcomes were cesarean delivery rate, spontaneous vaginal delivery rate, uterine hyperstimulation and tachysystole, and labor duration from oxytocin infusion.

RESULTS

Eight RCTs with 3,154 patients were included. High dose oxytocin did not reduce cesarean delivery rate compared to low dose oxytocin (OR=0.76, 95% CI [0.52, 1.10], p=0.15). After solving the reported heterogeneity, high dose oxytocin did not increase the rate of spontaneous vaginal deliveries vs. low dose oxytocin (OR=1.06, 95% CI [0.84, 1.32], p=0.64). Low dose oxytocin was linked to a significant decline in uterine hyperstimulation and tachysystole (p>0.001). A reduction in labor duration was found in high dose oxytocin group over low oxytocin regimen (MD=-1.02 h, 95% CI [-1.77, -0.27], p=0.008).

CONCLUSIONS

We found no advantages for high dose oxytocin over low dose oxytocin in labor augmentation except in reducing labor duration. Low dose oxytocin is safer as it decreases the incidence of uterine hyperstimulation and tachysystole. More trials are needed to confirm our findings.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

High dose and low dose oxytocin regimens as determinants of successful labor induction: a multicenter comparative study

BACKGROUND

Induction of labor by Oxytocin is a routine obstetric procedure. However, little is known regarding the optimal dose of oxytocin so as to bring successful induction. This study was aimed at comparing the effects of high dose versus low dose oxytocin regimens on success of labor induction.

METHODS

Hospital-based comparative cross-sectional study was conducted in four selected hospitals in Ethiopia prospectively from October 1, 2017 to May 30, 2018. A total of 216 pregnant women who undergo induction of labor at gestational age of 37 weeks and above were included. Data were entered into Epi-data version 3.1 and then exported to SPSS version 20 for cleaning and analysis. Chi-square test and logistic regression were done to look for determinants of successful induction. The result was presented using 95% confidence interval of crude and adjusted odds ratios. P-value < 0.05 was used to declare statistical significance.

RESULT

The mean "Induction to delivery time" was 5.9 h and 6.3 h for participants who received high dose Oxytocin and low dose Oxytocin respectively. Higher successful induction (72.2% versus 61.1%) and lower Cesarean Section rate (27.8% vs. 38.9) were observed among participants who received low dose Oxytocin compared to high dose. Favourable bishop score [AOR 4.0 95% CI 1.9, 8.5], elective induction [AOR 0.2 95% CI 0.1, 0.4], performing artificial rupture of membrane [AOR 10.1 95% CI 3.2, 32.2], neonatal birth weight of <4Kg [AOR 4.3, 95% CI 1.6, 11.6] and being parous [AOR 2.1 95% CI 1.1, 4.0] were significantly associated with success of induction.

CONCLUSIONS

In this study, Different oxytocin regimens didn't show significant association with success of induction. But, high dose oxytocin regimen was significantly associated with slightly shorter induction to delivery time. Favourable bishop score, emergency induction, performing artificial rupture of membrane and delivery to non-macrosomic fetuses were positive determinants of successful induction. We recommend researchers to conduct multicenter research on a large number of patients that controls confounders to see the real effects of different oxytocin regimens on success of labor induction.

Evaluation of the implementation of a protocol for the restrictive use of oxytocin during spontaneous labor

INTRODUCTION

Use of oxytocin is associated with uterine hyperstimulation and postpartum hemorrhage with a dose-dependent effect. We aimed to evaluate the effect of the implementation of a protocol for the restrictive use of oxytocin during spontaneous labor on obstetric and neonatal outcomes.

MATERIAL AND METHODS

We performed an observational before-and-after study among 2174 women in spontaneous labor with a term singleton cephalic fetus. Obstetric and neonatal outcomes were compared according to the period, before (period A) and after (period B) the implementation of a protocol for the restrictive use of oxytocin.

RESULTS

1235 women were included in period A and 939 in period B. Compared to period A, the use of oxytocin during period B was significantly lower (45.5 vs. 35.1%, p<0.001) in both nulliparous (61.2 vs 54.6%, p=0.04) and multiparous women (34.0 vs. 21.1%, p<0.001). Labor was significantly longer in period B, both in nulliparous (6.7 vs. 7.9 h, p<0.01) and multiparous women (4.1 vs. 4.5 h, p<0.01). A lower frequency of uterine hyperstimulation (6.6 vs. 2.7%, p=0.01) was observed in period B. The odds of instrumental and cesarean delivery were not different between the periods (respectively adjusted odds ratio (AOR), 95% confidence interval (CI), 1.1(0.8-1.4); 1.2(0.8-1.8)) including for nulliparous women (respectively, 1.3(0.9-1.7); 1.3(0.8-1.9)).

DISCUSSION

Reducing the use of oxytocin during spontaneous labor through the implementation of a protocol may reduce the iatrogenic effects without increasing the risk of caesarean section but this implies longer duration of labor.

INADEQUATE ADHERENCE TO THE RECOMMENDATIONS REGARDING LABOR INDUCTION AS A TRIGGER OF CESAREAN SECTION IN WOMEN WITH SINGLE, TERM PREGNANCY. A DESCRIPTIVE STUDY

OBJECTIVE

To describe the characteristics of the labor induction process associated with the excess number of cesarean sections in women subjected to this intervention.

METHODS

Descriptive historical. cohort that included pregnant women without a history of previous cesarean section, with single term pregnancy and cephalic presentation who were subjected to labor induction in a Level III com- plexity hospital in Medellín, Colombia, during the time period between May 2015 and October 2016. Consecutive sampling was used. Measured variables were maternal age, parity, gestational age, indica- tion for labor induction, cervical favorability, time of induction, quality of uterine activity achieved, type of delivery, and time point during induction when the decision of cesarean section was made. The clinical practice guidelines of international organizations of the specialty and the new guides arising from the 2012 proposal of limiting the first cesarean section were used in order to define ad- herence to the recommendations for induction.

RESULTS

Of the 2402 births, 289 which met the inclusion criteria were selected. Cesarean section was performed in 48% of the women subjected to induction, 60.8% nulliparous and 32.1% multiparous. Of those with unfavorable cervix, 72.2% received oxytocin for cervical maturation. Of the women subjected to delivery induction, 108 (37%) underwent cesarean section due to a diagnosis of failed induction. This was considered inadequate in all of them, considering that the diagnosis was made before reaching a dilatation of 6 cm in 88 (81.5%), with intact membranes in 67 (62%), with no uterine activity in 42 (38.9%), with poor quality uterine activity in 23 (21.3%) and in 55 (61%) who did not have at least 24 hours of latent phase before undergoing cesarean section.

CONCLUSIONS

Failure to adhere to the recommendations for adequate induction was found, added to a mistaken diagnosis of failed induction.

Classification of Primary Caesarean Sections in Labor and its Usefulness for Analysis of Slovenian Perinatal Data

Objective

To determine the usefulness of a novel classification of indications for caesarean section (CS) in labour in recognizing differences in clinical practice in different maternity units.

Methods

Data from the National Perinatal Information System (NPIS) for 2013 and 2014 were used to classify indications for CS in nulliparous women with spontaneous onset of labour at ≥37 weeks with single cephalic foetuses within 14 Slovenian maternity units into foetal distress and different sub-groups of dystocia according to use and dosage of oxytocin. Chi-square test was used for statistical comparison between units (P≤0.05 significant).

Results

There were 13,572 deliveries and 1,567 (12.0%) CS in nulliparous patients with spontaneous onset of labour at ≥37 weeks with single cephalic foetuses in Slovenia during the study period. Rates of CS in this group of women differed significantly among different maternity units (from 4.1% to 20.9%; P<0.001) suggesting significant differences in clinical practice. The most common indication for CS was cephalopelvic disproportion, which was diagnosed with different frequency in different units (from 11.2% to 45.9%; odds ratio 6.72; 95% confidence interval 3.10– 14.71; P<0.001).

Conclusions

It is possible to use NPIS data to retrospectively classify indications for CS. Such classification reveals significant differences among maternity units and could allow for a meaningful analysis of CS rates in different hospitals leading to evidence-based initiatives to decrease the incidence of primary CS.

Update on uterine tachysystole

Uterine tachysystole (TS) is a potentially significant intrapartum complication seen most commonly in induced or augmented labors but may also occur in women with spontaneous labor. When it occurs, maternal and perinatal complications can arise if not identified and managed promptly by obstetric care providers. Over recent years, new definitions of the condition have facilitated further research into the field, which has been synthesized to inform clinical management guidelines and protocols. We propose a set of recommendations pertaining to TS in line with contemporary evidence and obstetric practice.

Design of Oxytocin Analogs

The neurohypophyseal hormone oxytocin (OT) and related modulators of the oxytocin receptor (OTR) have been the subject of intensive research for nearly seven decades. Despite having rather poor drug-like properties, OT is used as a treatment for labor induction, postpartum hemorrhage, and lactation support. The potential use of OT in the treatment of central nervous system (CNS)-related diseases has recently renewed interest in the pharmacology of OT. Oxytocin is one of the most extensively studied cyclic peptides and since the elucidation of its structure in 1953 thousands of peptidic OT analogs with antagonistic and agonistic properties have been synthesized and biologically evaluated. Among them are atosiban, a mixed oxytocin receptor (OTR)/vasopressin 1a receptor (V_1aR) antagonist used as a tocolytic agent approved (in certain countries), and carbetocin, a longer acting OTR agonist on the market for the treatment of postpartum hemorrhage. Many other OT analogs with improved pharmacological properties (e.g., barusiban, Antag III) have been identified. These peptides have been tested in clinical trials and/or used as pharmacological tools. In this chapter, the modifications of the OT molecule that led to the discovery of these compounds are reviewed.

Does perinatal exposure to exogenous oxytocin influence child behavioural problems and autistic-like behaviours to 20 years of age?

BACKGROUND

The neuropeptide and hormone oxytocin is known to have a significant impact on social cognition and behaviour in humans. There is growing concern regarding the influence of exogenous oxytocin (OT) administration in early life on later social and emotional development, including autism spectrum disorder (ASD). No study has examined offspring development in relation to the dose of exogenous oxytocin administered during labour.

METHODS

Between 1989 and 1992, 2,900 mothers were recruited prior to the 18th week of pregnancy, delivering 2,868 live offspring. The Child Behaviour Checklist was used to measure offspring behavioural difficulties at ages 5, 8, 10, 14 and 17 years. Autism spectrum disorder was formally diagnosed by consensus of a team of specialists. At 20 years, offspring completed a measure of autistic-like traits, the Autism Spectrum Quotient (AQ). Oxytocin exposure prior to birth was analysed using categorical and continuous approaches (maternal oxytocin dose) with univariate and multivariate statistical techniques.

RESULTS

Categorical analyses of oxytocin exposure prior to birth demonstrated no group differences in any measures of child behaviour. A small in magnitude dose-response association was observed for clinically significant total behaviour symptoms (adjusted odds ratio 1.03; 95% CI: 1.01-1.06, p < .01). Exogenous oxytocin administration prior to birth was not associated with ASD (OR: 0.64; 95% CI: 0.15-2.12, p = .46) or high levels of autistic-like traits (p = .93), as assessed by the AQ.

CONCLUSIONS

This study is the first to investigate longitudinal mental health outcomes associated with the use of oxytocin-based medications during labour. The results do not provide evidence to support the theory that exogenous OT has a clinically significant negative impact on the long-term mental health of children.

High-dose versus low-dose of oxytocin for labour augmentation: a randomised controlled trial

PROBLEM

Delayed labour progress is common in nulliparous women, often leading to caesarean section despite augmentation of labour with synthetic oxytocin.

BACKGROUND

High- or low-dose oxytocin can be used for augmentation of delayed labour, but evidence for promoting high-dose is weak. Aim To ascertain the effect on caesarean section rate of high-dose versus low-dose oxytocin for augmentation of delayed labour in nulliparous women. Methods Multicentre parallel double-blind randomised controlled trial (ClinicalTrials.gov: NCT01587625) in six labour wards in Sweden. Healthy nulliparous women at term with singleton cephalic fetal presentation, spontaneous labour onset, confirmed delay in labour and ruptured membranes (n=1351) were randomised to labour augmentation with either high-dose (6.6 mU/minute) or low-dose (3.3 mU/minute) oxytocin infusion.

FINDINGS

1295 women were included in intention-to-treat analysis (high-dose n=647; low-dose n=648). Caesarean section rates did not differ between groups (12.4% and 12.3%, 95% Confidence Interval -3.7 to 3.8). Women with high-dose oxytocin had: shorter labours (-23.4min); more uterine tachysystole (43.2% versus 33.5%); similar rates of instrumental vaginal births, with more due to fetal distress (43.8% versus 22.7%) and fewer due to failure to progress (39.6% versus 58.8%). There were no differences in neonatal outcomes.

DISCUSSION

Our study could not confirm results of two systematic reviews indicating, with weak evidence, that use of high-dose oxytocin was associated with lower frequency of caesarean section.

CONCLUSION

We found no advantages for routine use of high-dose oxytocin in the management of delay in labour. Low-dose oxytocin regimen is recommended to avoid unnecessary events of tachysystole and fetal distress.

Errors and pitfalls in reading the cardiotocographic tracing

Reading of fetal heart rate (FHR) tracing during labor remains one of the most controversial and problematic issues in Obstetrics. The incorrect interpretation of CTG can be due to errors and pitfalls. Some common errors are related to the incorrect use of oxytocin, specifically the failure to recognize tachysystole, to correct it and to use oxytocin to accelerate labor when the fetal heart rate tracing is not reassuring. A common error is also the incorrect interpretation of deceleration that leads to unnecessary and often dangerous interventions, despite the clarification of the significance of decelerations, which in themselves are not a sign of impending acidosis, except when they are accompanied by loss of variability. Another potential error that can be identified as a pitfall is the transition from fetal to maternal heart rate (MHR) recording. The misidentification of MHR as FHR can potentially mask pathological FHR traces, appearing as a falsely reassuring trace.

Administration of oxytocin during spontaneous labour: A national vignette-based study among midwives

OBJECTIVE

(1) to assess variations in oxytocin use by midwives during spontaneous labour (indication, dose, moment), and (2) to identify factors potentially associated with oxytocin administration.

DESIGN

descriptive cross-sectional study using a case-vignette and questionnaire among French midwives from November 2015 to May 2016.

METHODS

Midwives were asked to complete an online survey including a case-vignette with hourly partograms of a slowly progressing labour, and a short self-administered questionnaire. Two choices were proposed with each hourly partogram: administration of oxytocin or expectant management. Midwives who selected oxytocin were then asked about the dose, dose-increment and dose-increase delay. The questionnaire asked the midwives about work experience, day or night work, and organisational factors.

FINDINGS

The study included 204 midwives. At some point during the case-vignette, 159 (77.9%) midwives responded that they would use oxytocin. Answers demonstrated variations in oxytocin administration for initial doses, dose-increments and dose-increase delays. Specifically, a substantial majority of respondents chose high doses of oxytocin (64.1% at doses exceeding 2 mIU/min) and short dose-increase delays (62.9% under 30 min). Excessive administration of oxytocin by midwives was significantly associated with the number of births per year in their maternity unit, midwives' workload (p < 0.001), overload of delivery rooms (p < 0.001) and lack of protocol (22% versus 55.6%, p < 0.001). Midwives considered that their use of oxytocin was related mainly to an overburdened department (48.5%).

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

We observed overuse of oxytocin, influenced by organisational factors. Every maternity unit should implement a protocol and/or checklist for oxytocin administration to reduce variation in practice and improve safety of care by using evidence-based clinical indications, initial doses, dose-increments and dose-increase delays. Modifying the organisation of care appears necessary to reduce hospital patient volume or increase staffing to ensure that the number of midwives on duty matches the activity in the delivery room without causing excess work or stress to midwives.

Effects of Increased Frequency, High Dose, and Pulsatile Oxytocin Regimens on Abnormal Labor Delivery

Background

The current guideline for oxytocin regimens in the abnormal labor of delivery is continuous infusion. The objective of the present study was to compare effects and safety measures of various available regimens of oxytocin in abnormal labor delivery.

Material/Methods

In this clinical experimental study, a total of 900 pregnant women admitted for delivery were randomized into 5 group with 162 each. Pregnant women received oxytocin as continuous administration of 16 mU/min (Group I), 1 mU/min (group II), 4 mU/min (group III), 5 mU/min quarter-hourly (group IV), and through a syringe pump (group V). Measurement of the expense of delivery, the ratio of the instrumental delivery, and the other secondary outcome measures was performed to find the best regimen of oxytocin. The 2-tailed paired t test and Mann-Whitney U test following Dunnett’s multiple comparison tests were used at 95% confidence level.

Results

Pulsatile delivery had least risk of instrumental delivery as compared to continuous infusion (p<0.0001, q=6.663) and normal-frequency low-dose (p<0.0001, q=5.638) of oxytocin. The time required from infusion to delivery was longer for group II (p=0.001, q=2.925), group IV (p<0.0001, q=4.829), and group V (p<0.0001, q=41.456) than for group I. The expense of delivery was: group I < group II < group IV < group III < group V.

Conclusions

High-dose and pulsatile preparation of oxytocin had reduced risks of operative delivery vs. continuous administration.

Risk Factors for Brachial Plexus Birth Injury

Over the course of decades, the incidence of brachial plexus birth injury (BPBI) has increased despite advances in healthcare which would seem to assist in decreasing the rate. The aim of this study is to identify previously unknown risk factors for BPBI and the risk factors with potential to guide preventative measures. A case control study of 52 mothers who had delivered a child with a BPBI injury and 132 mothers who had delivered without BPBI injury was conducted. Univariate, multivariable and logistic regressions identified risk factors and their combinations. The odds of BPBI were 2.5 times higher when oxytocin was used and 3.7 times higher when tachysystole occurred. The odds of BPBI injury are increased when tachysystole and oxytocin occur during the mother's labor. Logistic regression identified a higher risk for BPBI when more than three of the following variables (>30 lbs gained during the pregnancy, stage 2 labor >61.5 min, mother's age >26.4 years, tachysystole, or fetal malpresentation) were present in any combination.

Accelerated Titration of Oxytocin in Nulliparous Women with Labour Dystocia: Results of the ACTION Pilot Randomized Controlled Trial

OBJECTIVE

The primary objective was to determine the feasibility of a large RCT assessing the effectiveness of an accelerated oxytocin titration (AOT) protocol compared with a standard gradual oxytocin titration (GOT) in reducing the risk of CS in nulliparous women diagnosed with dystocia in the first stage of labour. The secondary objective was to obtain preliminary data on the safety and efficacy of the foregoing AOT protocol.

METHODS

This was a multicentre, double-masked, parallel-group pilot RCT. This study was conducted in three Canadian birthing centres. A total of 79 term nulliparous women carrying a singleton pregnancy in spontaneous labour, with a diagnosis of labour dystocia, were randomized to receive either GOT (initial dose 2 mU/min with increments of 2 mU/min) or AOT (initial dose 4 mU/min with increments of 4 mU/min), in a 1:1 ratio. An intention-to-treat analysis was applied.

RESULTS

A total of 252 women were screened and approached, 137 (54.4%) consented, and 79 (31.3%) were randomized. Overall protocol adherence was 76 of 79 (96.2%). Of the women randomized, 10 (25.6%) allocated to GOT had a CS compared with six (15.0%) allocated to AOT (Fisher exact test P = 0.27).

CONCLUSION

This pilot study demonstrated that a large, multicentre RCT is not only feasible, but also necessary to assess the effectiveness and safety of an AOT protocol for labour augmentation with regard to CS rate and indicators of maternal and perinatal morbidities.

A Review of the Safety, Efficacy and Mechanisms of Delivery of Nasal Oxytocin in Children: Therapeutic Potential for Autism and Prader-Willi Syndrome, and Recommendations for Future Research

In this article, we conduct a comprehensive review of existing evidence for the safety and therapeutic potential of intranasal oxytocin in pediatric populations. Unique considerations for dosing and delivery of oxytocin to the nasal passageway in pediatric populations and methods to promote adherence are reviewed. Intranasal oxytocin has been administered to 261 children in three open-label studies and eight randomized controlled trials. To date, the only published results in pediatric populations have focused on autism spectrum disorder (ASD) and Prader-Willi syndrome (PWS). Results regarding efficacy for improving social impairment in ASD are equivocal, partially due to mixed methodological designs, dosing regimens, and outcome measures. At present, there is no randomized controlled evidence that oxytocin provides benefit to individuals with PWS. There is no clear evidence of a link between oxytocin administration and any specific adverse event. Adverse events have been assessed using medical interviews, open reports, checklists, and physiological assessments. Adverse events reports have been largely classified as mild (n = 93), with few moderate (n = 9) or severe (n = 3) events reported. There were 35 additional adverse events reported, without severity ratings. Severe events, hyperactivity and irritability, occurred at first administration in both placebo and oxytocin groups, and subsided subsequent to discontinuation. We note that adverse event monitoring is inconsistent and often lacking, and reporting of its relationship to the study drug is poor. Only one study reported adherence data to suggest high adherence. Recommendations are then provided for the delivery of nasal sprays to the nasal passageway, monitoring, and reporting of efficacy, safety, and adherence for oxytocin nasal spray trials in pediatric populations.

Labor stimulation with oxytocin: effects on obstetrical and neonatal outcomes

OBJECTIVE

to evaluate the effects of labor stimulation with oxytocin on maternal and neonatal outcomes.

METHOD

descriptive and analytical study with 338 women who gave birth at a tertiary hospital. Obstetric and neonatal variables were measured and compared in women submitted and non-submitted to stimulation with oxytocin. Statistics were performed using Chi-square test, Fisher exact test, Student t-test; and crude Odds Ratio with 95% confidence interval were calculated. A p < 0.05 was considered statistically significant.

RESULTS

stimulation with oxytocin increases the rates of cesarean sections, epidural anesthesia and intrapartum maternal fever in primiparous and multiparous women. It has also been associated with low pH values of umbilical cord blood and with a shorter duration of the first stage of labor in primiparous women. However, it did not affect the rates of 3rd and 4th degree perineal lacerations, episiotomies, advanced neonatal resuscitation, 5-minute Apgar scores and meconium.

CONCLUSION

stimulation with oxytocin should not be used systematically, but only in specific cases. These findings provide further evidence to health professionals and midwives on the use of oxytocin during labor. Under normal conditions, women should be informed of the possible effects of labor stimulation with oxytocin.

When choice becomes limited: Women's experiences of delay in labour

Choice and patient involvement in decision-making are strong aspirations of contemporary healthcare. One of the most striking areas in which this is played out is maternity care where recent policy has focused on choice and supporting normal birth. However, birth is sometimes not straightforward and unanticipated complications can rapidly reduce choice. We draw on the accounts of women who experienced delay during labour with their first child. This occurs when progress is slow, and syntocinon is administered to strengthen and regulate contractions. Once delay has been recognized, the clinical circumstances limit choice. Drawing on Mol’s work on the logics of choice and care, we explore how, although often upsetting, women accepted that their choices and plans were no longer feasible. The majority were happy to defer to professionals who they regarded as having the necessary technical expertise, while some adopted a more traditional medical model and actively rejected involvement in decision-making altogether. Only a minority wanted to continue active involvement in decision-making, although the extent to which the possibility existed for them to do so was questionable. Women appeared to accept that their ideals of choice and involvement had to be abandoned, and that clinical circumstances legitimately changed events.

Patient safety during induction of labor

Rates of induction of labor have risen rapidly since 1990, from 9.6% in that year to a peak of 23.8% of the 2010 singleton births in the United States. Even as the definition of term pregnancy has been refined to reflect the continuing maturation needs of the fetus, and mothers have been encouraged to "go the full forty," management strategies for pregnancy conditions that increase risk have included early induction. Labor induction should only be undertaken when there are specific indications for interrupting the normal processes of pregnancy. These indications may relate to maternal, fetal, or placental conditions or simply reflect the understanding that in all pregnancies, the placenta will eventually lose its ability to adequately provide oxygen, nutrition, and waste removal for the fetus. Patient safety-for both the mother and the child-can be improved when clinicians practice within clinical guidelines that follow the best available evidence and women are able to make informed decisions regarding plans for labor.

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.

Is oxytocin a maternal-foetal signalling molecule at birth? Implications for development

The neuropeptide oxytocin was first noted for its capacity to promote uterine contractions and facilitate delivery in mammals. The study of oxytocin has grown to include awareness that this peptide is a neuromodulator with broad effects throughout the body. Accumulating evidence suggests that oxytocin is a powerful signal to the foetus, helping to prepare the offspring for the extrauterine environment. Concurrently, the use of exogenous oxytocin or other drugs to manipulate labour has become common practice. The use of oxytocin to expedite labour and minimise blood loss improves both infant and maternal survival under some conditions. However, further investigations are needed to assess the developmental consequences of changes in oxytocin, such as those associated with pre-eclampsia or obstetric manipulations associated with birth. This review focuses on the role of endogenous and exogenous oxytocin as a neurochemical signal to the foetal nervous system. We also examine the possible developmental consequences, including those associated with autism spectrum disorder, that arise from exogenous oxytocin supplementation during labour.

Factors associated with higher oxytocin requirements in labor

OBJECTIVE

To identify clinical characteristics associated with high maximum oxytocin doses in women who achieve complete cervical dilation.

METHODS

A retrospective nested case-control study was performed within a cohort of all term women at a single center between 2004 and 2008 who reached the second stage of labor. Cases were defined as women who had a maximum oxytocin dose during labor >20 mu/min, while women in the control group had a maximum oxytocin dose during labor of ≤20 mu/min. Exclusion criteria included no oxytocin administration during labor, multiple gestations, major fetal anomalies, nonvertex presentation, and prior cesarean delivery. Multiple maternal, fetal, and labor factors were evaluated with univariable analysis and multivariable logistic regression.

RESULTS

Maximum oxytocin doses >20 mu/min were administered to 108 women (3.6%), while 2864 women received doses ≤20 mu/min. Factors associated with higher maximum oxytocin dose after adjusting for relevant confounders included maternal diabetes, birthweight >4000 g, intrapartum fever, administration of magnesium, and induction of labor.

CONCLUSIONS

Few women who achieve complete cervical dilation require high doses of oxytocin. We identified maternal, fetal and labor factors that characterize this group of parturients.

Principles of endocrinology

The endocrine system plays a major role in human survival. Endocrine glands secrete chemical messengers or hormones that affect every tissue of the body, including the periodontium, during the life of the individual. As the endocrine system influences a broad assortment of biological activities necessary for life, a general understanding of the principal components and functions of this system is essential. A fundamental assessment of hormone structure, mechanism of action and hormone transport, as well as influence on homeostasis is reviewed. A concise evaluation of the functions of the central endocrine glands, the functions of the major peripheral endocrine glands (other than gonadal tissues) and the known relationships of these hormones to the periodontium is examined.

Clinical associations with uterine tachysystole

OBJECTIVES

To determine the incidence of uterine tachysystole (UT) and its association with neonatal depression or metabolic acidemia (DEP).

METHODS

This retrospective study comprised all 6234 women at ≥ 37 weeks' gestation who were monitored during the last 4 hours of tracings before birth in an academic community hospital. DEP was defined by an umbilical artery base deficit value ≥ 10 mmol/L or a 5-minute Apgar ≤ 6 and included 77 births. UT was defined by >15 contractions in 30 minutes.

RESULTS

The overall incidence of UT was 18.3% (1139/6234). In 4.2% (260/6234) UT persisted for >60 min. The rate of UT was similar in births with DEP (14.3%, 11/77) compared to those without DEP (18.3%, 1128/6157; p=0.45). In births with UT, only 1.0% (11/1139) developed DEP. The DEP group had more decelerations at almost every level of contractions and a higher cesarean rate of 49.4% (38/77) compared to 24.0% (1468/6124); p=<0.001 in the group without DEP.

CONCLUSIONS

UT was common, occasionally prolonged and almost always benign. Fetuses with DEP had no more UT than those without DEP. Many babies with DEP declared their vulnerability with decelerations at contraction rates below UT levels and the great majority of them never experienced UT.

High-dose versus low-dose oxytocin for augmentation of delayed labour

BACKGROUND

A major cause of failure to achieve spontaneous vaginal birth is delay in labour due to presumed inefficient uterine action. Oxytocin is given to increase contractions and high-dose regimens may potentially increase the number of spontaneous vaginal births, but as oxytocin can cause hyperstimulation of the uterus, there is a possibility of increased adverse events.

OBJECTIVES

To compare starting dose and increment dose of oxytocin for augmentation for women delayed in labour to determine whether augmentation by high-dose regimens of oxytocin improves labour outcomes and to examine the effect on both maternal/neonatal outcomes and women's birth experiences.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2013) and reference lists of retrieved studies.

SELECTION CRITERIA

We included all randomised and quasi-randomised controlled trials for women in delayed labour requiring augmentation by oxytocin comparing high-dose regimens (defined as starting dose and increment of equal to or more than 4 mU per minute) with low-dose regimens (defined as starting dose and an increment of less than 4 mU per minute). Increase interval: between 15 and 40 minutes. The separation of low- and high-dose regimens is based on an arbitrary decision.

DATA COLLECTION AND ANALYSIS

Four review authors undertook assessment of trial eligibility, risk of bias, and data extraction independently.

MAIN RESULTS

We included four studies involving 644 pregnant women. Three studies were randomised controlled trials and one trial was a quasi-randomised study. A higher dose of oxytocin was associated with a significant reduction in length of labour reported from one trial (mean difference (MD) -3.50 hours; 95% confidence interval (CI) -6.38 to -0.62; one trial, 40 women). There was a decrease in the rate of caesarean section (risk ratio (RR) 0.62; 95% CI 0.44 to 0.86 four trials, 644 women) and an increase in the rate of spontaneous vaginal birth in the high-dose group (RR 1.35; 95% CI 1.13 to 1.62, three trials, 444 women), although for both of these outcomes there were inconsistencies between studies in the size of effect. When we carried out sensitivity analysis (temporarily removing a study at high risk of bias) the differences between groups were no longer statistically significantThere were no significant differences between high- and low-dose regimens for instrumental vaginal birth, epidural analgesia, hyperstimulation, postpartum haemorrhage, chorioamnionitis or women's perceptions of experiences. For neonatal outcomes, there was no significant difference between groups for Apgar scores, umbilical cord pH, admission to special care baby unit, or neonatal mortality. The following outcomes were not evaluated in the included studies: perinatal mortality, uterine rupture, abnormal cardiotocography, women's pyrexia, dystocia and neonatal neurological morbidity.

AUTHORS' CONCLUSIONS

Higher-dose regimens of oxytocin (4 mU per minute or more) were associated with a reduction in the length of labour and in caesarean section, and an increase in spontaneous vaginal birth. However, there is insufficient evidence to recommend that high-dose regimens are advised routinely for women with delay in the first stage of labour. Further research should evaluate the effect of high-dose regimens of oxytocin for women delayed in labour and should include maternal and neonatal outcomes as well as the effects on women.

Standard- or high-dose oxytocin for nulliparous women with confirmed delay in labour: quantitative and qualitative results from a pilot randomised controlled trial

OBJECTIVE

Evidence suggests that a high dose of oxytocin for nulliparous women at 37-42 weeks of gestation with confirmed delay in labour increases spontaneous vaginal birth. We undertook a pilot study to test the feasibility of this treatment.

DESIGN

Pilot double-blind randomised controlled trial.

SETTING

Three teaching hospitals in the UK.

POPULATION

A total of 94 consenting nulliparous women at term with confirmed delay in labour were recruited, and 18 were interviewed.

METHODS

Women were assigned to either a standard (2 mU/min, increasing every 30 minutes to 32 mU/minute) or a high-dose regimen (4 mU/minute, increasing every 30 minutes to 64 mU/minutes) oxytocin by computer-generated randomisation. Simple descriptive statistics were used, as the sample size was insufficient to evaluate clinical outcomes. The constant comparative method was used to analyse the interviews.

MAIN OUTCOMES MEASURES

The main outcome measures: number of women eligible; maternal and neonatal birth; safety; maternal psychological outcomes and experiences; health-related quality of life outcomes using validated tools and data on health service resource use; incidence of suspected delay of labour (cervical dilatation of <2 cm after 4 hours, once labour is established); and incidence of confirmed delay of labour (progress of <1 cm on repeat vaginal examination after a period of 2 hours).

RESULTS

We successfully developed systems to recruit eligible women in labour and to collect data. Rates of spontaneous vaginal birth (10/47 versus 12/47, RR 1.2, 95% CI 0.6-2.5) and caesarean section (15/47 versus 17/47, RR 1.1, 95% CI 0.6-2.0) were increased, and rates of instrumental birth were reduced (21/47 versus 17/47, RR 0.8, 95% CI 0.5-1.3). No evidence of increased harm for either mother or baby was found. The incidences of suspected delay (14%) and confirmed delay (11%) in labour were less than anticipated. Of those who did not go on to have delayed labour confirmed, all except one woman gave birth vaginally.

CONCLUSIONS

A pilot trial assessing the efficacy of high-dose oxytocin was feasible, but uncertainty remains, highlighting the need for a large definitive trial. The implementation of national guidance of suspected and confirmed delay in labour is likely to reduce intervention.