Identification of latent phase factors associated with active labor duration in low-risk nulliparous women with spontaneous contractions

Symptoms of onset of labour and early labour: A scoping review

BACKGROUND

Early labour care often insufficiently addresses the individual needs of pregnant women leading to great dissatisfaction. In-depth knowledge about symptoms of onset of labour and early labour is necessary to develop women-centred interventions.

QUESTION OR AIM

To provide an overview on the current evidence about pregnant women's symptoms of onset of labour and early labour.

METHODS

We conducted a scoping review in the five databases PubMed, Web of Science, CINHAL Complete, PsychInfo and MIDIRS in May 2021 and August 2022 using a sensitive search strategy. A total of 2861 titles and abstracts and 290 full texts were screened independently by two researchers using Covidence. For this article, data was extracted from 91 articles and summarised descriptively and narratively.

FINDINGS

The most frequently mentioned symptoms were 'Contractions, labour pain' (n = 78, 85.7 %), 'Details about the contractions' (n = 51 articles, 56.0 %), 'Positive and negative emotions' (n = 50, 54.9 %) and 'Fear and worries' (n = 48 articles, 52.7 %). Details about the contractions ranged from a slight pulling to unbearable pain and the emotional condition varied from joy to great fear, showing an extraordinary diversity of symptoms highlighting the very individual character of early labour.

DISCUSSION

A comprehensive picture of varying and contradicting symptoms of onset of labour and early labour was drawn. Different experiences indicate different needs. This knowledge builds a good basis to develop women-centred approaches to improve early labour care.

CONCLUSION

Further research is necessary to design individualised early labour interventions and evaluate their effectiveness.

Latent phase duration and associated outcomes: a contemporary, population-based observational study

BACKGROUND

Little is known about the latent phase of labor, including whether its duration influences subsequent labor processes or birth outcomes.

OBJECTIVE

This study aimed to describe the duration of the latent phase of labor from self-report of the onset of painful contractions to a cervical dilation of 5 cm in a large, Swedish population and evaluate the association between the duration of the latent phase of labor and perinatal processes and outcomes that occurred during the active phase of labor, second stage of labor, birth and immediately after delivery, stratified by parity.

STUDY DESIGN

This was a population-based cohort study of 67,267 pregnancies with deliveries between 2008 and 2020 in the Stockholm-Gotland Regions, Sweden. Nulliparous and parous women without a history of cesarean delivery in spontaneous labor with a term (≥37 weeks of gestation), singleton, live, and vertex fetus without major malformations were included. Imputation was used if the notation of the end of the latent phase of labor (ie, cervical dilation of 5 cm) was missing in the partograph. Multivariable logistic regression was used to estimate the association with adjusted odds ratios and 95% confidence intervals, controlling for potential covariates.

RESULTS

Including the time from painful contraction onset to a cervical dilation of 5 cm, the median durations of the latent phase of labor were 16.0 (interquartile range, 10.0-26.6) hours for nulliparous women and 9.4 (interquartile range, 5.9-15.3) hours for multiparous women. The durations of the latent phase of labor beyond the median were associated with increased odds of labor dystocia diagnosis during the first stage active phase or second stage of labor and interventions commonly associated with dystocia (amniotomy, oxytocin augmentation, epidural, and cesarean delivery). The duration of the latent phase of labor of ≥90th percentile vs less than the median in nulliparous women demonstrated an increased risk of adverse neonatal outcomes (Apgar score of <7 at 5 minutes and neonatal intensive care unit admission), chorioamnionitis, and fetal occiput posterior. In multiparous women, longer duration of the latent phase of labor was associated with an increased risk of neonatal intensive care unit admission and chorioamnionitis but was not associated with an Apgar score of <7 at 5 minutes. The duration of the latent phase of labor was not associated with additional markers of maternal risk.

CONCLUSION

The duration of the latent phase of labor in nulliparous women was longer than that of multiparous women at each point of distribution. A longer duration of the latent phase of labor was associated with more frequent dystocia diagnoses and related interventions during the first stage active phase or second stage of labor, including cesarean delivery, nulliparous fetal occiput posterior position, chorioamnionitis, and markers of neonatal morbidity. More research is needed to identify potential mediating paths between the duration of the latent phase of labor and neonatal morbidity.

Outpatient management of pre-induction cervical ripening

INTRODUCTION

Induction of labor is a common obstetric intervention. For women requiring cervical ripening, the current standard practice of inpatient labor induction can be long and challenging. Outpatient cervical ripening may be a safe and beneficial option for a select subset of low-risk pregnant women.

METHODS

Electronic databases were searched with specific criteria to select articles for review. The review covered literature on the safety, efficacy and acceptability of outpatient cervical ripening in the low-risk population.

DISCUSSION

Pharmacological and mechanical cervical ripening agents have been trialed in the outpatient setting. Mechanical ripening is safer than pharmacological priming, and there appears to be no disadvantage to offering outpatient catheter balloon cervical ripening to appropriately screened women who require this intervention prior to labor induction. Maternal and midwifery acceptability of outpatient care further support outpatient cervical ripening for women with low-risk pregnancies.

CONCLUSION

The balloon catheter appears to be the optimal method for outpatient cervical ripening, but further prospective studies are required to ensure safety and benefit before it can be routinely offered to low-risk women.

Efficacy of hyoscine butyl-bromide in shortening the active phase of labor: Systematic review and meta-analysis of randomized trials

INTRODUCTION

Prolonged labor increases the risk of maternal and fetal complications. The active management of labor has been proven effective in lowering neonatal and maternal morbidity by shortening the duration of labor. Several pharmaceutical and non-pharmaceutical approaches are currently being used in the active management of labor. Hyoscine Butyl-bromide (HBB) is an antispasmodic and anticholinergic drug that acts as a cervical spasmolytic agent. It has been widely used in everyday practice for shortening the active phase of labor. Nonetheless, only a few trials have been conducted on the topic.

OBJECTIVE

This review aimed to evaluate whether HBB is effective in decreasing the mean duration of the active phase of labor.

STUDY DESIGN

An electronic search was conducted on Medline (through PubMed), Scopus, ClinicalTrials.gov, EMBASE, PROSPERO, and Cochrane Library from the beginning of all databases to December 2019. Results were limited to randomized trials. Restriction for English language was applied. Inclusion criteria were: randomized clinical trials regarding primiparae or multiparae women with a singleton vertex pregnancy at term who were randomized to HBB versus placebo or other drugs. Primary outcome evaluated was the mean reduction of the active phase of labor.

DATA COLLECTION AND ANALYSIS

Eight randomized clinical trials, including 1159 pregnant women, were analyzed. Significant heterogeneity (I² = 99 %) between studies was noted for the primary outcome. The active phase of labor duration was significantly reduced in the treatment arm compared to controls [mean difference (MD) -83.93 min (95 % confidence interval (CI) -163.61, -4.25)]. Achieved reduction in primiparae women was -55.09 min [95 % CI -68.83, -41.35; I² = 37 %].

CONCLUSION

HBB is an effective treatment to shorten the duration of the active phase of labor in primiparae and multiparae women.

Outpatient versus inpatient balloon catheter insertion for labor induction: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To compare between outpatient and inpatient balloon catheter insertion for labor induction.

METHODS

We searched in four different databases for the available trials during May 2020. We included randomized controlled trials (RCTs) that compared outpatient to inpatient balloon catheter for induction of labor. We extracted the available data from the included studies and pooled them in meta-analysis using RevMan software. The dichotomous data were pooled as risk ratio (RR) and the continuous data were pooled as mean difference (MD) with the corresponding 95% confidence intervals (CI).Our primary outcome was the rate of cesarean delivery. Our secondary outcomes were the length of hospital stay, Bishop score, and different adverse events including postpartum hemorrhage, Apgar score less than 7 at 5 minutes, and chorioamnionitis.

RESULTS

Eight RCTs with a total number of 740patients were included. The cesarean delivery rate was significantly reduced among outpatient balloon catheter compared to inpatient balloon catheter (RR = 0.63, 95% CI [0.46, 0.86], p = 0.004). Outpatient balloon catheter was associated with shorter hospital stay duration in comparison with inpatient group (MD= -0.38, 95% CI [-0.61, -0.14], p = 0.002). Outpatient group was linked to a more favorable increase in Bishop score (MD = 0.88, 95% CI [0.78, 0.98], p>0.001). There were no significant differences between both groups regarding different adverse events.

CONCLUSION

Outpatient balloon catheter priming is safe and effective in reducing cesarean delivery rates and shortening the length of hospital stay with a better Bishop score.

Perspectives on Promoting Hospital Primary Vaginal Birth: A Qualitative Study

BACKGROUND

One in three women will deliver by cesarean, a procedure that can be life saving, but which also carries short- and long-term risks. There is growing interest in preventing primary cesarean deliveries, while optimizing the health of the mother and infant. The primary aim of this study was to use participatory action strategies and ethnographic interview data collected from diverse stakeholders in birth (caregivers, women, policymakers) about facilitators and barriers to the achievement of primary vaginal birth in first-time mothers in hospital settings. The secondary aim was to use the findings to identify strategies to promote primary vaginal birth and future areas of research.

METHODS

Individual and small group interviews were conducted with caregivers and policymakers (N = 79) and first-time mothers (N = 24) at a northeastern hospital. All interviews were audio-recorded, transcribed, and analyzed using Atlas.ti.

RESULTS

Four broad themes were identified: 1) preparation for childbirth, 2) early labor management, 3) caregiver knowledge and practice style, and 4) birth environment (physical, cultural/emotional). The first two were closely linked from caregivers' perspectives. If the woman was not prepared for childbirth, it was perceived she would be more likely to present to the hospital in early labor. Once there, it was hard to prevent admission and interventions. A woman's knowledge and confidence were perceived as powerful mediators for vaginal birth.

CONCLUSION

Caregivers and first-time mothers identified early labor management and childbirth preparation as important factors to promote primary vaginal birth in hospital settings. Both deserve further inquiry as potential strategies to decrease rising cesarean delivery rates.

Diagnosing onset of labor: a systematic review of definitions in the research literature

BACKGROUND

The diagnosis of labor onset has been described as one of the most important judgments in maternity care. There is compelling evidence that the duration of both latent and active phase labor are clinically important and require consistent approaches to measurement. In order to measure the duration of labor phases systematically, we need standard definitions of their onset. We reviewed the literature to examine definitions of labor onset and the evidentiary basis provided for these definitions.

METHODS

Five electronic databases were searched using predefined search terms. We included English, French and German language studies published between January 1978 and March 2014 defining the onset of latent labor and/or active labor in a population of healthy women with term births. Studies focusing exclusively on induced labor were excluded.

RESULTS

We included 62 studies. Four 'types' of labor onset were defined: latent phase, active phase, first stage and unspecified. Labor onset was most commonly defined through the presence of regular painful contractions (71% of studies) and/or some measure of cervical dilatation (68% of studies). However, there was considerable discrepancy about what constituted onset of labor even within 'type' of labor onset. The majority of studies did not provide evidentiary support for their choice of definition of labor onset.

CONCLUSIONS

There is little consensus regarding definitions of labor onset in the research literature. In order to avoid misdiagnosis of the onset of labor and identify departures from normal labor trajectories, a consistent and measurable definition of labor onset for each phase and stage is essential. In choosing standard definitions, the consequences of their use on rates of maternal and fetal morbidity must also be examined.

Definition of Failed Induction of Labor and Its Predictive Factors: Two Unsolved Issues of an Everyday Clinical Situation

OBJECTIVE

The objectives of this review were to identify the predictive factors of induction of labor (IOL) failure or success as well as to highlight the current heterogeneity regarding the definition and diagnosis of failed IOL.

MATERIALS AND METHODS

Only studies in which the main or secondary outcome was failed IOL, defined as not entering the active phase of labor after 24 h of prostaglandin administration ± 12 h of oxytocin infusion, were included in the review. The data collected were: study design, definition of failed IOL, induction method, IOL indications, failed IOL rate, cesarean section because of failed IOL and predictors of failed IOL.

RESULTS

The database search detected 507 publications. The main reason for exclusion was that the primary or secondary outcomes were not the predetermined definition of failed IOL (not achieving active phase of labor). Finally, 7 studies were eligible. The main predictive factors identified in the review were cervical status, evaluated by the Bishop score or cervical length.

DISCUSSION

Failed IOL should be defined as the inability to achieve the active phase of labor, considering that the definition of IOL is to enter the active phase of labor. A universal definition of failed IOL is an essential requisite to analyze and obtain solid results and conclusions on this issue. An important finding of this review is that only 7 of all the studies reviewed assessed achieving the active phase of labor as a primary or secondary IOL outcome. Another conclusion is that cervical status remains the most important predictor of IOL outcome, although the value of the parameters explored up to now is limited. To find or develop predictive tools to identify those women exposed to IOL who may not reach the active phase of labor is crucial to minimize the risks and costs associated with IOL failure while opening a great opportunity for investigation. Therefore, other predictive tools should be studied in order to improve IOL outcome in terms of health and economic burden.

A randomized controlled trial on early induction compared to expectant management of nulliparous women with prolonged latent phases

OBJECTIVE

To compare early induction and expectant management regarding delivery outcomes and the experience of delivery in nulliparous women with prolonged latent phases.

DESIGN

Randomized controlled trial.

SETTING

One delivery unit in a Swedish hospital.

POPULATION

Nulliparous women at term experiencing continuous contractions impeding rest (women's report) and exceeding 18 h, a cervical dilation of less than 4 cm, intact membranes and with a singleton fetus in cephalic presentation.

METHODS

The women were randomly allocated to either early induction (n = 65) or expectant management (n = 64). All participants received medication for therapeutic rest. The early induction group was induced five hours after medication, and the expectant group awaited spontaneous onset of labor. The Wijma Delivery Experience Questionnaire (W-DEQ version B) was filled in after delivery.

MAIN OUTCOME MEASURES

The primary outcome was mode of delivery. Secondary outcomes included birth experience, duration of labor, postpartum hemorrhage, and neonatal outcomes.

RESULTS

The cesarean section rate was 15 of 65 (23.1%) in the early induction group and 24 of 64 (37.5%) in the expectant group (p = 0.076, OR 2.00, 95% CI 0.93-4.31). No significant differences were shown regarding delivery, neonatal outcomes or birth experience.

CONCLUSIONS

No significant differences were shown between the two groups in the rate of cesarean sections or the experience of delivery. According to the actual results, the power to detect a difference was only 45%. The cesarean section rate was high in both groups, regardless of intervention.

Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour

BACKGROUND

Slow progress in the first stage of spontaneous labour is associated with an increased caesarean section rate and fetal and maternal morbidity. Oxytocin has long been advocated as a treatment for slow progress in labour but it is unclear to what extent it improves the outcomes for that labour and whether it actually reduces the caesarean section rate or maternal and fetal morbidity. This review will address the use of oxytocin and whether it improves the outcomes for women who are progressing slowly in labour compared to situations where it is not used or where its administration is delayed.

OBJECTIVES

To determine if the use of oxytocin for the treatment of slow progress in the first stage of spontaneous labour is associated with a reduction in the incidence of caesarean sections, or maternal and fetal morbidity compared to situations where it is not used or where its administration is delayed.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 February 2013) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials which compared oxytocin with either placebo, no treatment or delayed oxytocin in the active stage of spontaneous labour in low-risk women at term.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion, assessed risk of bias and extracted data. We sought additional information from trial authors.

MAIN RESULTS

We included eight studies in the review involving a total of 1338 low-risk women in the first stage of spontaneous labour at term. Two comparisons were made; 1) the use of oxytocin versus placebo or no treatment (three trials); 2) the early use of oxytocin versus its delayed use (five trials). There were no significant differences in the rates of caesarean section or instrumental vaginal delivery in either comparison. Early use of oxytocin resulted in an increase in uterine hyperstimulation associated with fetal heart changes. However, the early use of oxytocin versus its delayed use resulted in no significant differences in a range of neonatal and maternal outcomes. Use of early oxytocin resulted in a statistically significant reduction in the mean duration in labour of approximately two hours but did not increase the normal delivery rate. There was significant heterogeneity for this analysis and we carried out a random-effects meta-analysis; however, all of the trials are strongly in the same direction so it is reasonable to conclude that this is the true effect. We also performed a random-effects meta-analysis for the four other analyses which showed substantial heterogeneity in the review.

AUTHORS' CONCLUSIONS

For women making slow progress in spontaneous labour, treatment with oxytocin as compared with no treatment or delayed oxytocin treatment did not result in any discernable difference in the number of caesarean sections performed. In addition there were no detectable adverse effects for mother or baby. The use of oxytocin was associated with a reduction in the time to delivery of approximately two hours which might be important to some women. However, if the primary goal of this treatment is to reduce caesarean section rates, then doctors and midwives may have to look for alternative options.

Women's perception of the onset of labour and epidural analgesia: a prospective study

OBJECTIVE

childbearing women and their midwives differ in their diagnoses of the onset of labour. The symptoms women use to describe the onset of labour are associated with the process of labour. Perinatal factors and women's attitudes may be associated with the administration of epidural analgesia. Our study aimed to assess the correlation between women's perception of the onset of labour and the frequency and timing of epidural analgesia during labour.

DESIGN

prospective cohort study.

SETTING

41 maternity units in Lower Saxony, Germany.

PARTICIPANTS

549 nulliparae (as defined in the "Methods" section) and 490 multiparae giving birth between April and October 2005. Women were included after 34 completed weeks of gestation with a singleton in vertex presentation and planned vaginal birth.

MEASUREMENTS

the association between women's symptoms at the onset of labour and the administration of epidural analgesia - frequency, timing in relation to onset of labour and cervical dilatation - was assessed. The analysis was performed by Kaplan-Meiers estimation, logistic regression and Cox regression.

FINDINGS

a total of 174 nulliparae and 49 multiparae received epidural analgesia during labour. Nulliparae received it at a median time of 5.47hrs (range: 0.25-51.17hrs) after onset of labour, at a median cervical dilatation of 3.3cm (range: 1.0-10.0cm). In multiparae, epidural analgesia was applied at a median time of 3.79hrs (range: 0.42-28.55hrs) after onset of labour; the median cervical dilatation was 3.0cm (range: 1.0-8.0cm). Women who were admitted with advanced cervical dilatation received epidural analgesia less often. Women who defined their onset of labour earlier than it was diagnosed by their midwives received epidural analgesia earlier. Gastrointestinal symptoms and irregular pain at the onset of labour were associated with later administration of epidural analgesia. Induction of labour was associated with a reduced interval from the onset of labour to epidural analgesia.

KEY CONCLUSIONS

women's self-diagnosis of the onset of labour and their perception of their labour duration when meeting their midwives has some impact on their admission to the labour ward and the timing of epidural analgesia.

IMPLICATIONS FOR PRACTICE

consideration of women's own perceptions and expectations regarding the onset and process of labour is necessary for individual care during labour.

Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour

BACKGROUND

Slow progress in the first stage of spontaneous labour is associated with an increased caesarean section rate and fetal and maternal morbidity. Oxytocin has long been advocated as a treatment for slow progress in labour but it is unclear to what extent it improves the outcomes for that labour and whether it actually reduces the caesarean section rate or maternal and fetal morbidity. This review will address the use of oxytocin and whether it improves the outcomes for women who are progressing slowly in labour compared to situations where it is not used or where its administration is delayed.

OBJECTIVES

To determine if the use of oxytocin for the treatment of slow progress in the first stage of spontaneous labour is associated with a reduction in the incidence of caesarean sections, or maternal and fetal morbidity compared to situations where it is not used or where its administration is delayed.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials which compared oxytocin with either placebo, no treatment or delayed oxytocin in the active stage of spontaneous labour in low-risk women at term.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion, assessed risk of bias and extracted data. We sought additional information from trial authors.

MAIN RESULTS

We included eight studies in the review involving a total of 1338 low-risk women in the first stage of spontaneous labour at term. Two comparisons were made; 1) the use of oxytocin versus placebo or no treatment (three trials); 2) the early use of oxytocin versus its delayed use (five trials). There were no significant differences in the rates of caesarean section or instrumental vaginal delivery in either comparison. Early use of oxytocin resulted in an increase in uterine hyperstimulation associated with fetal heart changes. However, the early use of oxytocin versus its delayed use resulted in no significant differences in a range of neonatal and maternal outcomes. Use of early oxytocin resulted in a statistically significant reduction in the mean duration in labour of approximately two hours but did not increase the normal delivery rate. There was significant heterogeneity for this analysis and we carried out a random-effects meta-analysis; however, all of the trials are strongly in the same direction so it is reasonable to conclude that this is the true effect. We also performed a random-effects meta-analysis for the four other analyses which showed substantial heterogeneity in the review.

AUTHORS' CONCLUSIONS

For women making slow progress in spontaneous labour, treatment with oxytocin as compared with no treatment or delayed oxytocin treatment did not result in any discernable difference in the number of caesarean sections performed. In addition there were no detectable adverse effects for mother or baby. The use of oxytocin was associated with a reduction in the time to delivery of approximately two hours which might be important to some women. However, if the primary goal of this treatment is to reduce caesarean section rates, then doctors and midwives may have to look for alternative options.