Inconsistent definitions of prolonged labor in international literature: a scoping review

Objective

Prolonged labor is the commonest indication for intrapartum cesarean section, but definitions are inconsistent and some common definitions were recently found to overestimate the speed of physiological labor. The objective of this review is to establish an overview of synonyms and definitions used in the literature for prolonged labor, separated into first and second stages, and establish types of definitions used.

Data sources

A systematic search was conducted in PubMed, Embase, Web of Science, Cochrane Library, Emcare, and Academic Search Premier.

Study eligibility criteria

All articles in English that (1) attempted to define prolonged labor, (2) included a definition of prolonged labor, or (3) included any synonym for prolonged labor, were included.

Methods

Data on study design, year of publication, country or region of origin, synonyms used, definition of prolonged first and/or second stage, and origin of provided definition (if not primarily established by the study) were collected into a database.

Results

In total, 3402 abstracts and 536 full-text papers were screened, and 232 papers were included. Our search established 53 synonyms for prolonged labor. Forty-three studies defined prolonged labor and 189 studies adopted a definition of prolonged labor. Definitions for prolonged first stage of labor were categorized into: time-based (n=14), progress-based (n=12), clinician-based (n=5), or outcome-based (n=4). For the 33 studies defining prolonged second stage, the majority of definitions (n=25) were time-based, either based on total duration or duration of no descent of the presenting part.

Conclusions

Despite efforts to arrive at uniform labor curves, there is still little uniformity in definitions of prolonged labor. Consensus on which definition to use is called for, in order to safely and respectfully allow physiological labor progress, ensure timely management, and assess and compare incidence of prolonged labor between settings.

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.

Outcome of Inducing Labor in Pregnancies with Suspected Fetal Growth Restriction: Oxytocin Discontinuation during the Active Phase of Labor versus Conventional Management

OBJECTIVE

Although fetal growth restriction (FGR) is associated with an increased risk of cesarean delivery during induced labor, there is limited evidence to guide labor management. This study aimed to investigate the prognosis of induced labor in pregnancies with suspected FGR and whether oxytocin discontinuation during the active phase of labor affects maternal and neonatal outcomes.

STUDY DESIGN

This retrospective cohort study investigated singleton pregnancies with vertex presentation and indications for labor induction owing to FGR after 34.0 weeks of gestation at Osaka University Hospital. From January 2010 to December 2013, women were conventionally managed, and oxytocin was continued until delivery unless there was an indication for discontinuation (conventional management group). From January 2013 to December 2020, oxytocin was routinely discontinued, or the dose was reduced at the beginning of the active phase of labor (oxytocin discontinuation group).

RESULTS

A total of 161 women (conventional management group, n = 74; oxytocin discontinuation group, n = 87) were included. After the active phase of induced labor, the total incidence of cesarean delivery was very low (3.1%), and the duration was short (173 ± 145 minutes). Oxytocin discontinuation was associated with lower cesarean delivery (1.1 vs. 5.4%; p = 0.12) and uterine tachysystole (9.8 vs. 23.0%; p = 0.08) rates and longer duration of the second stage of labor (mean: 56.5 ± 90 vs. 34.2 ± 45 minutes; p = 0.08) than conventional management; however, the difference was not significant. The other maternal and neonatal outcomes, including postpartum hemorrhage, did not also significantly differ between them.

CONCLUSION

After the active phase of induced labor for suspected FGR, the risk of cesarean delivery is low, and the high incidence of uterine tachysystole and rapid labor progression should be considered cautiously. Oxytocin can be safely discontinued during the active phase of labor in women undergoing labor induction for FGR without an increased risk of cesarean delivery or other unfavorable outcomes.

KEY POINTS

· The cesarean delivery rate was low after the active phase.. · The labor progress after the active phase was rapid.. · Oxytocin can be safely discontinued during the active phase..

Oxytocin augmentation and neurotransmitters in prolonged delivery: An experimental appraisal

The uterus is a highly innervated organ, and during labor, this innervation is at its highest level. Oxytocinergic fibers play an important role in labor and delivery and, in particular, the Lower Uterine Segment, cervix, and fundus are all controlled by motor neurofibers. Oxytocin is a neurohormone that acts on receptors located on the membrane of the smooth cells of the myometrium. During the stages of labor and delivery, its binding causes myofibers to contract, which enables the fundus of the uterus to act as a mediator. The aim of this study was to investigate the presence of oxytocinergic fibers in prolonged and non-prolonged dystocic delivery in a cohort of 90 patients, evaluated during the first and second stages of labor. Myometrial tissue samples were collected and evaluated by electron microscopy, in order to quantify differences in neurofibers concentrations between the investigated and control cohorts of patients. The authors of this experiment showed that the concentration of oxytocinergic fibers differs between non-prolonged and prolonged dystocic delivery. In particular, in prolonged dystocic delivery, compared to non-prolonged dystocic delivery, there is a lower amount of oxytocin fiber. The increase in oxytocin appeared to be ineffective in patients who experienced prolonged dystocic delivery, since the dystocic labor ended as a result of the altered presence of oxytocinergic fibers detected in this group of patients.

Evaluation of labor management practices during spontaneous labor

INTRODUCTION

In 2017, the French national authority for health issued national guidelines to support physiologic labor and reduce medical interventions. This study's primary aim was to evaluate the association between the publication of these guidelines and the vaginal delivery rate in a type IIb perinatal center. The secondary objectives were to evaluate the implementation of these guidelines, their association with the duration of labor, and the rates of postpartum hemorrhage and adverse neonatal outcomes.

MATERIAL AND METHODS

A before-and-after, retrospective, single-center study comparing a "before" group (2016) and an "after" group (2018), one year after the recommendations were published. Women were eligible if they had no prior cesarean delivery and gave birth after 37 weeks of gestation to a singleton fetus in cephalic presentation after spontaneous labor. The analysis was stratified by parity.

RESULTS

Oxytocin administration decreased between the two periods (48% vs 35 %, P < 0.0001), as did the frequency of amniotomies (artificial rupture of membranes) (39.5 % vs 27.7 %, P < 0.0001). The duration of labor was significantly prolonged (360 vs 390 min, P < 0.0001), especially in nulliparous women (465 min vs 562 min, P<0.0001). The frequency of vaginal delivery rose between the two periods (94.6 % vs 96 %, P = 0.05), and the postpartum hemorrhage rate fell (6 % vs 4.5 %, P = 0.04). The numbers of neonates with an umbilical artery pH< 7.10 and of neonatal transfers also decreased.

CONCLUSIONS

The reduction of active interventions during labor is associated with a longer duration of labor and a decrease in the rates of cesarean births, postpartum hemorrhages, and neonatal transfers.

Perceptions of healthcare professionals regarding labour induction and augmentation: A qualitative systematic review

BACKGROUND

Labour induction and augmentation procedures are commonly used in maternity units with or without medical indications. Research shows that healthcare professionals play a significant role in women's childbirth decisions.

AIM

To consolidate healthcare professionals' perceptions about labour induction and augmentation.

METHODS

Seven electronic databases were searched from their inception dates till January 2023: PubMed, Embase, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest Dissertations, and Theses Global. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis and Sandelowski and Barroso's guidelines guided this review. Included studies' quality was appraised by the Critical Appraisal Skills Program tool. Data were thematically synthesised. Review findings were assessed using the Grading of Recommendations Assessment, Development, and Evaluation-Confidence in the Evidence from Reviews of Qualitative research approach.

FINDINGS

Three main themes were identified from the 17 included studies: 1) Making sense of the phenomenon, 2) Two sides of the coin, and 3) The enlightened path ahead.

DISCUSSION

Healthcare professionals' labour induction and augmentation decisions were affected by personal (knowledge and moral philosophies), and external factors (women, community members, colleagues, and healthcare institutions). Some clinicians were unfamiliar with the proper labour induction/augmentation procedures, while others were worried about their decisions and outcomes.

CONCLUSION

Suggestions for improvement include conducting labour induction/augmentation training for clinicians, having sufficient resources in facilities, and developing appropriate labour induction/augmentation clinical guidelines. Women and their partners, community members, and traditional healers could benefit from receiving labour induction/augmentation education. To improve health outcomes, healthcare professionals could deliver woman-centred care and collaborate.

Oxytocin is not associated with postpartum hemorrhage in labor augmentation in a retrospective cohort study in the United States

BACKGROUND

Previous studies reported conflicting results on the relationship between oxytocin use for labor augmentation and the risk of postpartum hemorrhage, probably because it is rather challenging to disentangle oxytocin use from labor dystocia.

OBJECTIVE

This study aimed to investigate the independent association between oxytocin use for augmentation and the risk of postpartum hemorrhage by using advanced statistical modeling to control for labor patterns and other covariates.

STUDY DESIGN

We used data from 20,899 term, cephalic, singleton pregnancies of patients with spontaneous onset of labor and no previous cesarean delivery from Intermountain Healthcare in Utah in the Consortium on Safe Labor. Presence of postpartum hemorrhage was identified on the basis of a clinical diagnosis. Propensity scores were calculated using a generalized linear mixed model for oxytocin use for augmentation, and covariate balancing generalized propensity score was applied to obtain propensity scores for the duration and total dosage of oxytocin augmentation. A weighted generalized additive mixed model was used to depict dose-response curves between the duration and total dosage of oxytocin augmentation and the outcomes. The average treatment effects of oxytocin use for augmentation on postpartum hemorrhage and estimated blood loss (mL) were assessed by inverse probability weighting of propensity scores.

RESULTS

The odds of both postpartum hemorrhage and estimated blood loss increased modestly when the duration and/or total dosage of oxytocin used for augmentation increased. However, in comparison with women for whom oxytocin was not used, oxytocin augmentation was not clinically or statistically significantly associated with estimated blood loss (6.5 mL; 95% confidence interval, 2.5-10.3) or postpartum hemorrhage (adjusted odds ratio, 1.02; 95% confidence interval, 0.82-1.24) when rigorously controlling for labor pattern and potential confounders. The results remained consistent regardless of inclusion of women with an intrapartum cesarean delivery.

CONCLUSION

The odds of postpartum hemorrhage and estimated blood loss increased modestly with increasing duration and total dosage of oxytocin augmentation. However, in comparison with women for whom oxytocin was not used and after controlling for potential confounders, there was no clinically significant association between oxytocin use for augmentation and estimated blood loss or the risk of postpartum hemorrhage.

Association of oxytocin augmentation and duration of labour with postpartum haemorrhage: A cohort study of nulliparous women

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.

Early versus delayed amniotomy with immediate oxytocin after Foley catheter cervical ripening in multiparous women with labor induction: A randomized controlled trial

OBJECTIVE

To evaluate immediate oxytocin and early amniotomy compared with delayed amniotomy after Foley catheter cervical ripening in multiparous women on intervention-to-delivery interval.

METHODS

This randomized trial was conducted in Malaysia in 232 term multiparous women with balloon catheter-ripened cervixes (dilatation ≥3 cm), singleton fetus, cephalic presentation with intact membranes, and reassuring fetal heart rate tracing. They were randomized to immediate titrated intravenous oxytocin infusion and early amniotomy (116) or delayed amniotomy after 4 h of oxytocin (116). Primary outcome was intervention (oxytocin initiation)-to-delivery interval.

RESULTS

Oxytocin-to-delivery intervals were a median of 4.99 h (interquartile range [IQR], 3.21-7.82 h) versus 6.23 h (IQR, 4.50-8.45 h) (P < 0.001) for the early versus delayed amniotomy arms, respectively. Delivery rate at 4 h and 6 h after oxytocin infusion were 40 of 116 (35%) versus 22 of 116 (19%) (relative risk [RR], 1.82 [95% confidence interval (CI), 1.16-2.86], P = 0.011) and 77 of 116 (66%) versus 54 of 116 (47%) (RR, 1.43 [95% CI, 1.13-1.80], P = 0.003) for the early versus delayed amniotomy arms, respectively. Maternal satisfaction on birth process were 7 (IQR, 6-8) versus 7 (IQR, 7-8) (P = 0.006), uterine hyperstimulation rates were 10 of 116 (9%) versus 14 of 116 (12%) (RR, 0.71 [95% CI, 0.33-1.54]) (P = 0.519), and Cesarean delivery rates were 17 of 116 (15%) versus 19 of 116 (16%) (RR, 0.90 [95% CI, 0.49-1.63], P = 0.856) for the early versus delayed amniotomy arms, respectively.

CONCLUSION

In multiparas at term following cervical ripening by Foley catheter, immediate oxytocin and early amniotomy compared with a scheduled 4-h delay to amniotomy shortens the interval to birth and decreases uterine hyperactivity in labor but lowers maternal satisfaction. The cesarean delivery rate is not significantly reduced.

CLINICAL TRIAL REGISTRATION

This study was registered with the International Standard Randomised Controlled Trial Number (ISRCTN) on September 29, 2020, with trial identification number: ISRCTN87066007 (https://doi.org/10.1186/ISRCTN87066007). The first participant was recruited on September 29, 2020, after ISRCTN registry confirmation was received.

Exploring the impact of indication on variation in rates of intrapartum caesarean section in six Palestinian hospitals: a prospective cohort study

BACKGROUND

Caesarean section rates are rising globally. No specific caesarian section rate at either country-level or hospital-level was recommended. In Palestinian government hospitals, nearly one-fourth of all births were caesarean sections, ranging from 14.5 to 35.6%. Our aim was to assess whether variation in odds for intrapartum caesarean section in six Palestinian government hospitals can be explained by differences in indications.

METHODS

Data on maternal and fetal health were collected prospectively for all women scheduled for vaginal delivery during the period from 1st March 2015 to 30th November 2016 in six government hospitals in Palestine. Comparisons of proportions in sociodemographic, antenatal obstetric characteristics and indications by the hospital were tested by χ2 test and differences in means by one-way ANOVA analysis. The odds for intrapartum caesarean section were estimated by logistic regression. The amount of explained variance was estimated by Nagelkerke R square.

RESULTS

Out of 51,041 women, 4724 (9.3%) underwent intrapartum caesarean section. The prevalence of intrapartum caesarean section varied across hospitals; from 7.6 to 22.1% in nulliparous, and from 5.8 to 14.1% among parous women. The most common indications were fetal distress and failure to progress in nulliparous, and previous caesarean section with an additional obstetric indication among parous women. Adjusted ORs for intrapartum caesarean section among nulliparous women ranged from 0.42 (95% CI 0.31 to 0.57) to 2.41 (95% CI 1.70 to 3.40) compared to the reference hospital, and from 0.50 (95% CI 0.40-0.63) to 2.07 (95% CI 1.61 to 2.67) among parous women. Indications explained 58 and 66% of the variation in intrapartum caesarean section among nulliparous and parous women, respectively.

CONCLUSION

The differences in odds for intrapartum caesarean section among hospitals could not be fully explained by differences in indications. Further investigations on provider related factors as well as maternal and fetal outcomes in different hospitals are necessary.

The perspectives of nurse-midwives and doctors on clinical challenges of prolonged labor: A qualitative study from Tanzania

INTRODUCTION

METHODS

RESULTS

CONCLUSIONS

Oxytocin Administration in Low-Risk Women, a Retrospective Analysis of Birth and Neonatal Outcomes

BACKGROUND

In recent years, higher than the recommended rate of oxytocin use has been observed among low-risk women. This study examines the relationship between oxytocin administration and birth outcomes in women and neonates.

METHODS

A retrospective analysis of birth and neonatal outcomes for women who received oxytocin versus those who did not. The sample included 322 women with a low-risk pregnancy.

RESULTS

Oxytocin administration was associated with cesarean section (aOR 4.81, 95% CI: 1.80-12.81), instrumental birth (aOR 3.34, 95% CI: 1.45-7.67), episiotomy (aOR 3.79, 95% CI: 2.20-6.52) and length of the second stage (aOR 00:18, 95% CI: 00:04-00:31). In neonatal outcomes, oxytocin in labor was associated with umbilical artery pH ≤ 7.20 (OR 3.29, 95% CI: 1.33-8.14). Admission to neonatal intensive care unit (OR 0.56, 95% CI: 0.22-1.42), neonatal resuscitation (OR 1.04, 95% CI: 0.22-1.42), and Apgar score <7 (OR 0.48, 95% CI: 0.17-1.33) were not associated with oxytocin administration during labor.

CONCLUSIONS

Oxytocin administration during labor for low-risk women may lead to worse birth outcomes with an increased risk of instrumental birth and cesarean, episiotomy and the use of epidural analgesia for pain relief. Neonatal results may be also worse with an increased proportion of neonates displaying an umbilical arterial pH ≤ 7.20.

The Effect of Photobiomodulation on Analgesia During Childbirth: A Controlled and Randomized Clinical Trial

Background: Pain during labor can be a barrier when choosing vaginal delivery. In an attempt to relief pain during labor, several pharmacological and nonpharmacological methods are proposed. Objective: To assess the effect of light-emitting diode (LED) photobiomodulation on analgesia during labor. Methods: A clinical trial was conducted with 29 women who were divided into two groups: G1 (experimental group-LED) and G2 (control group-hot shower). In the experimental group, an LED plate with red and infrared merged [red 660 ± 20 nm, 5 mW/cm², 3 J per LED (108 J) and infrared 850 ± 20 nm, 5 mW/cm², 3 J per LED (108 J), total energy = 216 J] was placed on the subjects' dorsal region, at the level of T10 to S4, for 10 min, with the plate automatically turning off. Hot shower at controlled temperature was offered for 30 min. To verify the effect of LED on analgesia during labor, the following variables were assessed: (1) perception of pain, (2) fetal well-being assessed by cardiotocography or intermittent auscultation of fetal heart rate, (3) Apgar score at minutes 1 and 5 after birth, and (4) labor duration. Results: There was a statistically significant difference (p < 0.05) in pain reduction evidenced by a millimetric visual scale, before and after application on G1-LED (7.92 ± 1.78). Regarding the other variables, there was no statistical difference between the groups when comparing fetal well-being, Apgar score and labor duration. Conclusions: It is concluded that LED can be considered an alternative, since it caused pain reduction without changing other parameters during labor, compared with hot shower, a method included in hospital protocols, proving to be safe. Clinical Trial Registration number: NCT03496857.

[Impact of a protocol based on the new national recommendations on the use of oxytocin and its maternal-fetal consequences: A single-center before/after study]

OBJECTIVE

Evaluate oxytocin use and impact on maternal and fetal morbidity before and after implementation of a protocol based on national recommendations.

MATERIALS AND METHODS

A single-center retrospective before-and-after study (Lille, France). A service protocol to harmonize the use of oxytocin was implemented in May 2017 following national recommendations. Data were collected from January to March 2016 for period 1, and from January to March 2019 for period 2. Nulliparous patients in spontaneous labor=37SA delivering a live newborn in cephalic presentation were included. The primary outcome was the use of oxytocin.

RESULTS

Five hundred eighty-seven patients were included, 302 for period 1 and 285 for period 2. The rate of oxytocin use was 48% (n=144) in 2016 versus 28% (n=79) in 2019 (P<0.001). Total labor time was significantly longer after protocol implementation (425.7min vs. 510.4min ; P<0.001). The cesarean section rate was identical between the 2 periods (7.0% vs. 6.0%; P=0.62). The rate of postpartum hemorrhage greater than 500mL was higher in period 1 (17.7% vs. 10.9%; P=0.019), as was the occurrence of a pH<7.05 (5.4% vs. 1.1%; P=0.004).

CONCLUSION

The implementation of a protocol contributed to a decrease in the use of oxytocin and thus would allow a decrease in the rate of postpartum hemorrhage and neonatal acidosis, but with an increase in the duration of labor.

Management of oxytocin for labour augmentation in relation to mode of birth in Robson group 1

OBJECTIVE

To compare mode of birth in Robson group 1 according to administration of oxytocin for labour augmentation.

DESIGN AND PARTICIPANTS

A retrospective review of 724 medical records from women in Robson group 1 was performed. The outcome measurements were: mode of birth in relation to presence of labour dystocia when initiating augmentation with oxytocin, duration of augmentation with oxytocin, increase of the oxytocin infusion according to recommendations and cervical dilation when initiating augmentation with oxytocin.

SETTING

The review was based on medical records from a medium-sized tertiary level obstetric unit in southern Sweden, with approximately 3700 births per year. Data was collected between January 2017 and October 2017.

MEASUREMENTS AND FINDINGS

Oxytocin for labour augmentation was used in 64.1% of the births. Oxytocin administered according to the national recommendations was related to a greater likelihood of vaginal birth than when these recommendations were not followed. Only 47.8% of the women who underwent a caesarean section was treated according to recommendations. Receiving augmentation with oxytocin at a later stage of labour was related to a greater likelihood of a vaginal birth. The total time treated with oxytocin was significantly longer in women who had an assisted vaginal birth or a caesarean section than those who had a vaginal birth with augmentation.

KEY CONCLUSIONS

Oxytocin for labour augmentation was over-used in Robson group 1. Oxytocin early in labour, a long duration of stimulation with oxytocin and a slower increase of the infusion than recommended had a relationship with caesarean section.

IMPLICATION FOR PRACTICE

Due to risks for adverse maternal and neonatal outcomes when using oxytocin for labour augmentation, caregivers should implement strict protocols for its use. According to a high use of oxytocin there is a need to describe women's experiences of labour augmentation in labour dystocia but also when received despite normal labour progress.

Oxytocin and emergency caesarean section in a mediumsized hospital in Pakistan: A cross-sectional study

INTRODUCTION

One of the most common complications during labor is prolonged labor (dystocia), which is associated with risks for the mother and fetus. Dystocia is usually treated with oxytocin, which is also used to induce labor. Oxytocin may not have the desired effect of progress and can negatively affect the fetus, thus resulting in an emergency caesarean section (CS). The aim of this study was to describe obstetric practice, use of oxytocin and its association with an emergency CS.

METHODS

A cross-sectional retrospective register study was conducted that included all women who gave birth during 2014 and 2015 at a hospital in a large city in Pakistan.

RESULTS

A total of 6652 women gave birth to 6767 newborns, 66.8% were multiparous and 33.2% primiparous women. Of the primiparous women, 78.9% had a spontaneous vaginal birth, 1.2% an elective CS and 14.4% an emergency CS. Of the multiparous women, 81.9% had a spontaneous vaginal birth, 8.0% an elective CS and 6.7% an emergency CS. Operative vaginal birth was 2.1% among primiparous and 0.2% among multiparous women. Oxytocin for induction or augmentation was administered to 60.0% of primiparous and 30.5% of multiparous women. Oxytocin during the first stage of labor was associated with an increased risk for emergency CS for both primiparous and multiparous women.

CONCLUSIONS

Despite the association between oxytocin and emergency CS, the CS rate was low in this hospital. The majority of the women gave birth vaginally, even with a breech presentation. Few operative vaginal births were performed.

The effect of the implementation of institutional checklist on expert opinion of oxytocin use in labor

PURPOSE

Oxytocin is a commonly used drug in the labor and delivery unit. There are wide variations in oxytocin use between countries and medical centers, which may reflect the lack of structured guidelines. The aim of our study was to evaluate the need of oxytocin checklist in labor and delivery unit, while assessing the management of oxytocin with and without such a checklist.

METHODS

This study was conducted in a single, university-affiliated medical center in two phases: before and after the implementation of an oxytocin checklist in the labor and delivery unit (2016-2017). Six experts reviewed cardiotocographs of deliveries performed in an urgent Cesarean delivery due to non-reassuring fetal heart rate, after completing at least 4 h of oxytocin infusion for induction or augmentation of labor. The experts included three obstetricians, a midwife, and two obstetrical expert nurses, who were tasked to conclude whether oxytocin was managed properly or not. Each case was reviewed by two reviewers separately. A total of 100 cases were reviewed; 50 before the oxytocin checklist implementation, and 50 after that implementation.

RESULTS

We did not find a difference in the reviewers' assessment of oxytocin management before and after the institutional implementation of the checklist. Additionally, there were significant inconsistencies and inter-observer variations in their assessment before and after the checklist implementation.

CONCLUSION

The implementation of an institutional oxytocin checklist did not affect expert assessment of the use of oxytocin in labor.

Augmentation of labour

Augmentation of labour aims at improving the efficiency of uterine contractions in order to reduce maternal and foetal adverse outcomes associated with prolonged labour. This review covers the current best practice for different methods of augmentation of labour, namely, artificial rupture of membranes and oxytocin infusion as a prevention of, or therapy for, prolonged labour. The review highlights essential practice points and identifies knowledge gaps for future research in this important area of clinical obstetric practice.

[Effects of a policy for reasonable use of oxytocin during spontaneous labor at term]

OBJECTIVE

To assess the effect of a modified definition of dystocia and of a different timing of interventions during spontaneous labor on the rate of oxytocin use and on its consequences on labor outcome.

METHODS

We compared oxytocin use and labor outcome before and after the introduction of a new protocol for the management of spontaneous labor. By protocol, oxytocin use and/or artificial rupture of the membranes was restricted to cases without progress in cervical dilatation for≥1h and/or no progress of fetal descent for≥1h at full dilatation. The main outcome measure was the rate of oxytocin use. Secondary outcome criteria were the consequences on labor (duration of labor, tachysystole and uterine hyperstimulation, abnormal fetal heart rate, cesarean delivery rate) and neonatal outcome.

RESULTS

Oxytocin use was strongly reduced from 2015 (69.2%) to 2016 (39.8%; P<0.01) and 2017 (31.9%; P<0.01). Abnormal FHR rates decreased simultaneously (respectively 52%, 37% et 29%, P<0.05), as well as uterine hyperstimulation (respectively 33.6%, 21.3% et 23.0%; P<0.05). The cesarean delivery rate did not vary significantly from 2015 (11.5%) to 2016 (8.4%; NS) but it decreased from 2015 to 2017 (11.5% to 2.6%, respectively; P<0.05). No difference was found in postpartum hemorrhage rates or in neonatal outcome. The duration of labor was significantly longer for women who delivered in 2017, compared with 2015 (372 minutes versus 306 minutes, respectively; P<0.05). After multivariate analysis, FHR abnormalities were reduced (aOR 0.65 IC 95% [0.49-0.86]) as well as cesarean deliveries during labor (aOR 0.5 IC 95% [0.26-0.97]) in 2017 only, compared with the reference year 2015.

CONCLUSION

A simple and easy-to-use definition of dystocia and of interventions required during labor allowed a strong reduction of oxytocin use during labor with subsequent benefits such as reduced rates of FHR abnormalities, uterine hyperstimulations and cesarean deliveries, at the cost of a limited prolongation of labor, mainly in nulliparous women.

First assessed cervical dilatation: is it associated with oxytocin augmentation during labour? A retrospective cohort study in a university hospital in Switzerland

OBJECTIVES

The primary objective of this study was to examine the association between the first assessed cervical dilatation in a labourward and the use of oxytocin augmentation during labour. Further analysis was performed by examining the actual stage of labour at the point oxytocin was first administered to those women.

DESIGN

Retrospective cohort study with the data collected from the medical records of the hospital.

SETTING

University Hospital Bern, Switzerland PARTICIPANTS: 1933 term nulliparous and multiparous women with a singleton pregnancy giving birth during the period June 2013 and May 2017, representing Robson groups 1 and 3.

MEASUREMENTS AND FINDINGS

Descriptive statistics and multivariable logistic regression models were performed. It was found that for the entire process of labour, nulliparous and multiparous women (n = 1933) with a first cervical dilatation of 5 or more cm were less likely to be augmented with oxytocin (OR 0.64, 95% CI 0.46; 0.88 and OR 0.56, 95% CI 0.38; 0.82, respectively) compared to women with a first cervical dilatation of less than 5 cm. Out of these augmented women (n = 746) having a first cervical dilatation of 5 or more cm, they had a lower likelihood of being augmented during the first stage of labour compared to women with a first cervical dilatation of less than 5 cm (OR 0.45, 95% CI 0.29; 0.7 for nulliparae and OR 0.32, 95% CI 0.16; 0.6 for multiparae). Additionally, it was observed that other factors contributed to the application of oxytocin. One such example was that epidural analgesia was associated with a high risk of oxytocin augmentation in nulliparae (OR 13.88, 95% CI 9.29; 20.74) and multiparae (OR 15.52, 95% CI 9.94; 24.22). The application of oxytocin was also found to affect the caesarean section rate in nulliparous and multiparous women as it was 20% and 13% respectively for those with oxytocin versus 13% and 4% respectively for those without oxytocin.

KEY CONCLUSIONS

Early admission to the labourward is associated with an increased use of oxytocin to augment labour, particularly, during the first stage of labour. Epidural analgesia is a main predictor for oxytocin augmentation in nulliparous and multiparous women.

IMPLICATIONS FOR PRACTICE

Pregnant women warrant more appropriate support during early labour, avoiding early maternal exhaustion and excessive obstetrical interventions.

Determinants of Birth Asphyxia Among Newborns in Referral Hospitals of Amhara National Regional State, Ethiopia

Background

Globally, every year, 2.5 million infants die within their first month of life. Birth asphyxia is one of the leading causes in all low- and middle-income countries and the leading single cause of neonatal mortality in Ethiopia. Therefore, the aim of this study was to identify the determinants of birth asphyxia among newborns admitted to neonatal intensive care units (NICU) in Amhara region referral hospitals, Ethiopia.

Methods

Facility-based unmatched case-control study was employed from March 1 to April 30, 2018. Cases were newborn babies admitted to neonatal intensive care units with an admission criteria of birth asphyxia with APGAR score of <7 at five min of birth and controls were newborn babies admitted to NICU with an admission criteria of other complications (such as jaundice, congenital anomalies, sepsis, hemorrhagic diseases) with APGAR score of ≥7 at five min of birth. Using SPSS version 20, bivariate logistic regression model was fitted to check the relation of each independent variable to the outcome variable. Variables with p<0.2 in bivariate analysis were transferred to multivariable logistic regression model for final analysis. Variables with an adjusted odds ratio (AOR) of 95%CI and p<0.05 were reported as determinants of birth asphyxia.

Results

Data were collected from 193 cases and 193 controls with a response rate of 100%. Low birth weight (AOR: 8.94, 95%CI: 4.08, 19.56), born at health centers (AOR: 7.36, 95%CI: 2.44, 22.13), instrumental delivery (AOR: 3.03, 95%CI: 1.41, 6.49), and prolonged labor (AOR: 2.00, 95%CI: 1.20, 3.36) were significant determinants of birth asphyxia.

Conclusion

Even though most of the identified variables are the common and familiar causes of birth asphyxia, neonates born at health centers were more exposed to birth asphyxia than neonates born in hospitals. This might be due to delay of referral process and lack of skilled professionals in health centers. Further research might be needed to identify the root causes of delays and follow-up issues by adding qualitative component.

Changes in labor outcomes after implementing structured use of oxytocin augmentation with a 4-hour action line

Introduction: Oxytocin augmentation is essential in labor management, but how to optimize its use is still debated. Joint international guidelines regarding prolonged labor and the use of oxytocin augmentation are still not available. Due to its potential harmful side effects, a decreased use of oxytocin is encouraged. We aimed to implement a structured protocol on the use of oxytocin augmentation and to observe changes in labor outcomes.Materials and methods: The protocol was implemented at the Obstetric Department of Sørlandet Hospital, Kristiansand, Norway on 1 January 2012; therefore, data from the hospital were collected prospectively and compared for two time-period cohorts: the historic control cohort (2009-2010) and the study period cohort (2012-2013). The structured protocol instructs, and restricts, the birth attendants to diagnose prolonged labor, by protocol definition only, before commencing oxytocin infusion for augmentation. Nulliparous women with singleton, term deliveries (≥37 weeks), cephalic presentation, and spontaneous onset of labor (Ten-Group Classification System (TGCS) group 1) were included in the analysis. The main outcome was use of oxytocin augmentation.Results: The study cohort and control cohort comprised 1103 (26.2%) and 1399 (33.1%) of all laboring women, respectively (p < .01). The protocol was followed satisfactorily in 78% of the study cohort. The use of oxytocin augmentation was reduced in the study cohort versus the control cohort; 41.3 versus 48.9% (p < .01); mean oxytocin infusion duration was shorter (100 versus 123 min; p < .01); and mean total oxytocin dose decreased (1009 versus 1293 mU; p < .01). The cesarean section rate was 5.9% in the study cohort versus 8.0% in the control cohort (p = .04). The estimated mean duration of the active phase of labor increased by 47 min (p < .01) after the implementation. The frequency of estimated postpartum hemorrhage >1000 ml was higher, 4.9 versus 2.0% (p < .01), but the use of blood transfusions remained stable, 2.5 versus 2.7% (p = .78), the study cohort versus control cohort, respectively.Conclusions: Implementation of a protocol of structured use of oxytocin augmentation reduced the frequency, dosage, and duration of oxytocin without increasing the cesarean section rate in TGCS group 1.

The Labor Progression Study: The use of oxytocin augmentation during labor following Zhang's guideline and the WHO partograph in a cluster randomized trial

INTRODUCTION

This study aims to investigate the use of oxytocin augmentation during labor in nulliparous women following Zhang's guideline or the WHO partograph.

MATERIAL AND METHODS

This is a secondary analysis of a cluster randomized controlled trial in 14 birth-care units in Norway, randomly assigned to either the intervention group, which followed Zhang's guideline, or to the control group, which followed the WHO partograph, for labor progression. The participants were nulliparous women who had a singleton full-term fetus in a cephalic presentation and spontaneous onset of labor, denoted as group 1 in the Ten Group Classification System.

RESULTS

Between December 2014 and January 2017, 7277 participants were included. A total of 3219 women (44%) received augmentation with oxytocin during labor. Oxytocin was used in 1658 (42%) women in the Zhang group compared with 1561 (47%) women in the WHO group. The adjusted relative risk for augmentation with oxytocin was 0.98 (95% CI 0.84-1.15; P = .8) in the Zhang vs WHO group, with an adjusted risk difference of -0.8% (95% CI -7.8 to 6.1). The participants in the Zhang group were less likely to be augmented with oxytocin before reaching 6 cm of cervical dilatation (24%) compared with participants in the WHO group (28%), with an adjusted relative risk of 0.84 (95% CI 0.75-0.94; P = .003). Oxytocin was administered for almost 20 min longer in the Zhang group than in the WHO group, with an adjusted mean difference of 17.9 min (95% CI 2.7-33.1; P = .021). In addition, 19% of the women in the Zhang group and 23% in the WHO group received augmentation with oxytocin without being diagnosed with labor dystocia.

CONCLUSIONS

Although no significant difference in the proportion of oxytocin augmentation was observed between the 2 study groups, there were differences in how oxytocin was used. Women in the Zhang group were less likely to receive oxytocin augmentation before 6 cm of cervical dilatation. The duration of augmentation with oxytocin was longer in the Zhang group than in the WHO group.

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.

Augmentation of Labor: A Review of Oxytocin Augmentation and Active Management of Labor

Labor augmentation can be used to hasten labor, shorten the time to delivery, and perhaps reduce the risk of cesarean delivery. Particularly in women with longer labors or less frequent contractions, oxytocin augmentation seems to have positive impacts on these outcomes. Despite this, the evidence for augmentation alone on the risk of cesarean delivery is unclear, with varying evidence. More recently, oxytocin protocols have been recommended to standardize care and ensure patient safety.

A method to assess obstetric outcomes using the 10-Group Classification System: a quantitative descriptive study

OBJECTIVES

Internationally, the 10-Group Classification System (TGCS) has been used to report caesarean section rates, but analysis of other outcomes is also recommended. We now aim to present the TGCS as a method to assess outcomes of labour and delivery using routine collection of perinatal information.

DESIGN

This research is a methodological study to describe the use of the TGCS.

SETTING

Stavanger University Hospital (SUH), Norway, National Maternity Hospital Dublin, Ireland and Slovenian National Perinatal Database (SLO), Slovenia.

PARTICIPANTS

9848 women from SUH, Norway, 9250 women from National Maternity Hospital Dublin, Ireland and 106 167 women, from SLO, Slovenia.

MAIN OUTCOME MEASURES

All women were classified according to the TGCS within which caesarean section, oxytocin augmentation, epidural analgesia, operative vaginal deliveries, episiotomy, sphincter rupture, postpartum haemorrhage, blood transfusion, maternal age >35 years, body mass index >30, Apgar score, umbilical cord pH, hypoxic-ischaemic encephalopathy, antepartum and perinatal deaths were incorporated.

RESULTS

There were significant differences in the sizes of the groups of women and the incidences of events and outcomes within the TGCS between the three perinatal databases.

CONCLUSIONS

The TGCS is a standardised objective classification system where events and outcomes of labour and delivery can be incorporated. Obstetric core events and outcomes should be agreed and defined to set standards of care. This method provides continuous and available observations from delivery wards, possibly used for further interpretation, questions and international comparisons. The definition of quality may vary in different units and can only be ascertained when all the necessary information is available and considered together.

Obesity in pregnancy: a novel concept on the roles of adipokines in uterine contractility

Obesity is a global health problem even among pregnant women. Obesity alters quality of labor, such as preterm labor, prolonged labor, and higher oxytocin requirements in pregnant women. The most important factors to play a role in the altered gestational period and serve as drug targets to treat the consequences are female sexual hormones, calcium channels, adrenergic system, oxytocin, and prostaglandins. However, we have limited information about the impact of obesity on the pregnant uterine contractility and gestation time. Adipose tissue, which is the largest endocrine and paracrine organ, especially in obesity, is responsible for the production of adipokines and various cytokines and chemokines, and there are no reliable data available describing the relation between body mass index, glucose intolerance, and adipokines during pregnancy. Recent data suggest that the dysregulation of leptin, adiponectin, and kisspeptin during pregnancy contributes to gestational diabetes mellitus and pre-eclampsia. A preclinical method for obese pregnancy should be developed to clarify the action of adipokines and assess their impact in obesity. The deeper understanding of the adipokines-induced processes in obese pregnancy may be a step closer to the prevention and therapy of preterm delivery or prolonged pregnancy. Gestational weight gain is one of the factors that could influence the prenatal development, birth weight, and adiposity of newborn.

Risk factors for fatality in amniotic fluid embolism: a systematic review and analysis of a data pool

PURPOSE

Investigating risk factors for amniotic fluid embolism (AFE)-induced fatality.

METHODS

A systematic review of cases of AFE available on PubMed, Scielo, Scopus and AJOL databases that occurred from 1990 to 2015 was carried out. After careful reading of titles, abstracts and full texts, case reports of AFE were reviewed. Risk factors for AFE were considered as independent variables in logistic regression models. The first model was built on the whole data pool. The second model was built on typical cases of AFE, according to the classical triad of symptoms (heart, lungs, coagulopathy). The dependent variable was fatality in both models.

RESULTS

177 cases of AFE were assessed in the first model, while 121 typical cases of AFE were assessed in the second model. Among typical cases of AFE, only oxytocin infusion during labour increases the likelihood of death (odds ratio 2.890, 95% confidence interval 1.166-7.164, p = 0.022). No risk factors for fatality were found in the whole data pool.

CONCLUSIONS

Further research on national registries should focus on the behaviour of oxytocin infusion during labour in AFE cases.