New labor curves of dilation and station to improve the accuracy of predicting labor progress.

BACKGROUND: The diagnosis of failure to progress, the most common indication for intrapartum cesarean delivery, is based on the assessment of cervical dilation and station over time. Labor curves serve as references for expected changes in dilation and fetal descent. The labor curves of Friedman, Zhang et al, and others are based on time alone and derived from mothers with spontaneous labor onset. However, labor induction is now common, and clinicians also consider other factors when assessing labor progress. Labor curves that consider the use of labor induction and other factors that influence labor progress have the potential to be more accurate and closer to clinical decision-making. OBJECTIVE: This study aimed to compare the prediction errors of labor curves based on a single factor (time) or multiple clinically relevant factors using two modeling methods: mixed-effects regression, a standard statistical method, and Gaussian processes, a machine learning method. STUDY DESIGN: This was a longitudinal cohort study of changes in dilation and station based on data from 8022 births in nulliparous women with a live, singleton, vertex-presenting fetus ≥35 weeks of gestation with a vaginal delivery. New labor curves of dilation and station were generated with 10-fold cross-validation. External validation was performed using a geographically independent group. Model variables included time from the first examination in the 20 hours before delivery; dilation, effacement, and station recorded at the previous examination; cumulative contraction counts; and use of epidural anesthesia and labor induction. To assess model accuracy, differences between each model's predicted value and its corresponding observed value were calculated. These prediction errors were summarized using mean absolute error and root mean squared error statistics. RESULTS: Dilation curves based on multiple parameters were more accurate than those derived from time alone. The mean absolute error of the multifactor methods was better (lower) than those of the single-factor methods (0.826 cm [95% confidence interval, 0.820-0.832] for the multifactor machine learning and 0.893 cm [95% confidence interval, 0.885-0.901] for the multifactor mixed-effects method and 2.122 cm [95% confidence interval, 2.108-2.136] for the single-factor methods; P<.0001 for both comparisons). The root mean squared errors of the multifactor methods were also better (lower) than those of the single-factor methods (1.126 cm [95% confidence interval, 1.118-1.133] for the machine learning [P<.0001] and 1.172 cm [95% confidence interval, 1.164-1.181] for the mixed-effects methods and 2.504 cm [95% confidence interval, 2.487-2.521] for the single-factor [P<.0001 for both comparisons]). The multifactor machine learning dilation models showed small but statistically significant improvements in accuracy compared to the mixed-effects regression models (P<.0001). The multifactor machine learning method produced a curve of descent with a mean absolute error of 0.512 cm (95% confidence interval, 0.509-0.515) and a root mean squared error of 0.660 cm (95% confidence interval, 0.655-0.666). External validation using independent data produced similar findings. CONCLUSION: Cervical dilation models based on multiple clinically relevant parameters showed improved (lower) prediction errors compared to models based on time alone. The mean prediction errors were reduced by more than 50%. A more accurate assessment of departure from expected dilation and station may help clinicians optimize intrapartum management.

New insights on labor progression: a systematic review.

The past 20 years witnessed an invigoration of research on labor progression and a change of thinking regarding normal labor. New evidence is emerging, and more advanced statistical methods are applied to labor progression analyses. Given the wide variations in the onset of active labor and the pattern of labor progression, there is an emerging consensus that the definition of abnormal labor may not be related to an idealized or average labor curve. Alternative approaches to guide labor management have been proposed; for example, using an upper limit of a distribution of labor duration to define abnormally slow labor. Nonetheless, the methods of labor assessment are still primitive and subject to error; more objective measures and more advanced instruments are needed to identify the onset of active labor, monitor labor progression, and define when labor duration is associated with maternal/child risk. Cervical dilation alone may be insufficient to define active labor, and incorporating more physical and biochemical measures may improve accuracy of diagnosing active labor onset and progression. Because the association between duration of labor and perinatal outcomes is rather complex and influenced by various underlying and iatrogenic conditions, future research must carefully explore how to integrate statistical cut-points with clinical outcomes to reach a practical definition of labor abnormalities. Finally, research regarding the complex labor process may benefit from new approaches, such as machine learning technologies and artificial intelligence to improve the predictability of successful vaginal delivery with normal perinatal outcomes.

The sonopartogram.

The assessment of labor progress from digital vaginal examination has remained largely unchanged for at least a century, despite the current major advances in maternal and perinatal care. Although inconsistently reproducible, the findings from digital vaginal examination are customarily plotted manually on a partogram, which is composed of a graphical representation of labor, together with maternal and fetal observations. The partogram has been developed to aid recognition of failure to labor progress and guide management-specific obstetrical intervention. In the last decade, the use of ultrasound in the delivery room has increased with the advent of more powerful, portable ultrasound machines that have become more readily available for use. Although ultrasound in intrapartum practice is predominantly used for acute management, an ultrasound-based partogram, a sonopartogram, might represent an objective tool for the graphical representation of labor. Demonstrating greater accuracy for fetal head position and more objectivity in the assessment of fetal head station, it could be considered complementary to traditional clinical assessment. The development of the sonopartogram concept would require further undertaking of serial measurements. Advocates of ultrasound will concede that its use has yet to demonstrate a difference in obstetrical and neonatal morbidity in the context of the management of labor and delivery. Taking a step beyond the descriptive graphical representation of labor progress is the question of whether a specific combination of clinical and demographic parameters might be used to inform knowledge of labor outcomes. Intrapartum cesarean deliveries and deliveries assisted by forceps and vacuum are all associated with a heightened risk of maternal and perinatal adverse outcomes. Although these outcomes cannot be precisely predicted, many known risk factors exist. Malposition and high station of the fetal head, short maternal stature, and other factors, such as caput succedaneum, are all implicated in operative delivery; however, the contribution of individual parameters based on clinical and ultrasound assessments has not been quantified. Individualized risk prediction models, including maternal characteristics and ultrasound findings, are increasingly used in women's health-for example, in preeclampsia or trisomy screening. Similarly, intrapartum cesarean delivery models have been developed with good prognostic ability in specifically selected populations. For intrapartum ultrasound to be of prognostic value, robust, externally validated prediction models for labor outcome would inform delivery management and allow shared decision-making with parents.

A wider agreement is needed on basic intrapartum concepts.

Healthcare professionals working in labor wards worldwide regularly deal with the pressure of managing an emotionally charged and life-changing period for women, their families, and their friends. Furthermore, they frequently deal with long working hours, sleep deprivation, occasional scrutiny from the press, and legal dispute. The existing disagreements among leading scientific institutions on basic concepts of intrapartum care hinder the creation of a collective mental model in the labor ward, an aspect that is required for consistency in patient counseling and effective teamwork. Some of these disagreements are as follows: 1. When should laboring women be admitted to the hospital? 2. How long is the absence of labor progress acceptable before an intervention is proposed? 3. How long should women be allowed to push during the second stage of labor before an intervention is proposed? The international scientific community owes it to the vast number of healthcare professionals working in labor wards worldwide to agree on and provide clear definitions of these basic intrapartum concepts, thus making their work a little easier. International institutions, such as the International Federation of Gynecology and Obstetrics and the World Health Organization, have the highest authority to produce guidelines for the whole world, but the participation of leading national organizations, whose influence reaches well beyond the borders of their countries, is important for the wide dissemination of concepts.

Normal labor curve in twin gestation.

BACKGROUND: Failure to progress is one of the leading indications for cesarean delivery in trials of labor in twin gestations. However, assessment of labor progression in twin labors is managed according to singleton labor curves. OBJECTIVE: This study aimed to establish a partogram for twin deliveries that reflects normal and abnormal labor progression and customized labor curves for different subgroups of twin labors. STUDY DESIGN: This was a multicenter, retrospective cohort analysis of twin deliveries that were recorded in 3 tertiary medical centers between 2003 and 2017. Eligible parturients were those with twin gestations at ≥34 weeks' gestation with cephalic presentation of the presenting twin and ≥2 cervical examinations during labor. Exclusion criteria were elective cesarean delivery without a trial of labor, major fetal anomalies, and fetal demise. The study group comprised twin gestations, whereas singleton gestations comprised the control group. Statistical analysis was performed using Python 3.7.3 and SPSS, version 27. Categorical variables were analyzed using chi-square tests. Student t test and Mann-Whitney U test were applied to analyze the differences in continuous variables, as appropriate. RESULTS: A total of 1375 twin deliveries and 142,659 singleton deliveries met the inclusion criteria. Duration of the active phase of labor was significantly longer in twin labors than in singleton labors in both nulliparous and multiparous parturients; the 95th percentile duration was 2 hours longer in nulliparous twin labors and >3.5 hours longer in multiparous twin labors than in singleton labors. The cervical dilation progression rate was significantly slower in twin deliveries than in singleton deliveries with a mean rate in twin deliveries of 1.89 cm/h (95th percentile, 0.51 cm/h) and a mean rate of 2.48 cm/h (95th percentile, 0.73 cm/h) in singleton deliveries (P<.001). In addition, epidural use further slowed labor progression in twin deliveries. The second stage of labor was also markedly longer in twin deliveries, both in nulliparous and multiparous women (95th percentile, 3.04 vs 2.83 hours, P=.002). CONCLUSION: Twin labors are characterized by a slower progression of the active phase and second stage of labor compared with singleton labors in nulliparous and multiparous parturients. Epidural analgesia further slows labor progression in twin labors. Implementation of these findings in clinical management might lower cesarean delivery rates among cases with protracted labor in twin gestations.

Impact of analysis technique on our understanding of the natural history of labour: a simulation study.

OBJECTIVE: To evaluate the discrepancy between historical and more recent descriptions of the first stage of labour by testing whether the statistical techniques used recently (repeated-measures polynomial and interval-censored regression) were appropriate for detection of periods of rapid acceleration of cervical dilatation as might occur at the time of transition from a latent to an active phase of labour. DESIGN AND SETTING: A simulation study using regression techniques. SAMPLE: We created a simulated data set for 500 000 labours with clearly defined latent and active phases using the parameters described by Friedman. Additionally, we created a data set comprising 500 000 labours with a progressively increasing rate of cervical dilatation. METHODS: Repeated-measures polynomial regression was used to create summary labour curves based on simulated cervical examinations. Interval-censored regression was used to create centimetre-by-centimetre estimates of rates of cervical dilatation and their 95th centiles. MAIN OUTCOME MEASURES: Labour summary curves and rates of cervical dilatation. RESULTS: Repeated-measures polynomial regression did not detect the rapid acceleration in cervical dilatation (i.e. acceleration phase) and overestimated lengths of labour, especially at smaller cervical dilatations. There was a two-fold overestimation in the mean rate of cervical dilatation from 4 to 6 cm. Interval-censored regression overestimated median transit times, at 4- to 5-cm cervical dilatation or when cervical examinations occurred less frequently than 0.5- to 1.5-hourly. CONCLUSION: Repeated-measures polynomial regression and interval-censored regression should not be routinely used to define labour progress because they do not accurately reflect the underlying data. TWEETABLE ABSTRACT: Repeated-measures polynomial and interval-censored regression techniques are not appropriate to model first stage of labour.

Contemporary patterns of labor in nulliparous and multiparous women.

BACKGROUND: Controversy surrounds the definition of "normal" and "abnormal" labor. OBJECTIVE: In this study, we used contemporary labor charts to explore labor patterns in large obstetric population (2011-2016). STUDY DESIGN: Detailed information from electronic medical records of live singleton deliveries at term (≥37 weeks of gestation) was extracted. Cases of elective cesarean deliveries, nonvertex presentation, and cesarean deliveries during the first stage of labor were excluded. RESULTS: Overall, 35,146 deliveries were included, of whom 15,948 deliveries (45.3%) were of nulliparous women. Median cervical dilation at admission was not significantly different between nulliparous (median, 4 cm; interquartile range, 3-5 cm) and multiparous women (median, 4 cm; interquartile range, 3-6 cm). In all, 99.3% of the women delivered vaginally. For nulliparous women, the median duration of the first stage of labor was 274 minutes (interquartile range, 145-441 minutes; 95th percentile, 747.5 minutes). Likewise, for multiparous women, the corresponding duration was 133 minutes (interquartile range, 56-244 minutes; 95th percentile, 494 minutes). During the latent phase (cervical dilation at admission, ≤4 cm), the time elapsed to the second stage of labor was 120-140 minutes longer in nulliparous women, whereas the gap between the groups decreased dramatically with advanced cervical dilation on admission. Nulliparous and multiparous women appeared to progress at a similar pace during the latent phase; however, after 5 cm, labor accelerated faster in multiparous women. Epidural anesthesia lengthens duration first and second stages of labor in all parities. Partograms according to cervical dilation at presentation are proposed. CONCLUSION: Cervical dilation rate is relatively constant between nulliparous and multiparous pregnant women during the latent phase. Time interval of the first stage was far slower than previously described, which allowed labor to continue for a longer period during this stage. These findings may reduce the rate of intrapartum iatrogenic interventions.

Labor progress determined by ultrasound is different in women requiring cesarean delivery from those who experience a vaginal delivery following induction of labor.

BACKGROUND: The diagnosis of labor dystocia generally is determined by the deviation of labor progress, which is assessed by the use of a partogram. Recently, intrapartum transperineal ultrasound for the assessment of fetal head descent has been introduced to assess labor progress in the first stage of labor in a more objective and noninvasive way. OBJECTIVE: The objective of the study was to determine the differences in labor progress by the use of serial transperineal ultrasound assessment of fetal head descent between women having vaginal and cesarean delivery. STUDY DESIGN: This was a prospective longitudinal study performed in 315 women with singleton pregnancy who were undergoing labor induction at term between December 2016 and December 2017. Paired assessment of cervical dilation and fetal head station by vaginal examination and transperineal ultrasonographic assessment of parasagittal angle of progression and head-perineum distance were made serially after the commencement of labor induction. According to the hospital protocol, assessment was performed every 24 hours and 4 hours, respectively, during latent and active phases of labor. The researchers and the clinical team were blinded to each other's findings. The repeated measures data were analyzed by mixed effect models. To determine the effect of mode of delivery on the association between parasagittal angle of progression and head-perineum distance against fetal head station and cervical dilation, the significance of the interaction term between each mode of delivery and fetal head station or cervical dilation was determined, which accounted for parity and obesity. Area under receiver-operating characteristic curve was used to evaluate the performance of serial intrapartum sonography in predicting women with cesarean delivery because of failure to progress. RESULTS: The total number of paired vaginal examination and ultrasound assessments was 1198, with a median of 3 per woman. The median assessment-to-assessment interval was 4.6 hours (interquartile range, 4.3-5.1 hours). Women who achieved vaginal delivery (n=261) had steeper slopes of parasagittal angle of progression and head-perineum distance against fetal head station and cervical dilation than those who achieved cesarean delivery (n=54). Objectively, an additional decrease of 5.11 and 1.37 degrees in parasagittal angle of progression was observed for an unit increase in fetal head station and cervical dilation, respectively, in women who required cesarean delivery (P<.01; P=.01), compared with women who achieved vaginal delivery, after taking account of repeated measures from individuals and confounding factors. The respective additional increases in head-perineum distance for a unit increase in fetal head station and cervical dilation were 0.27 cm (P<.01) and 0.12 cm (P<.01). A combination of maternal characteristics with the temporal changes of parasagittal angle of progression for an unit increase in fetal head station achieved an area under receiver-operating characteristic curve of 0.85 (95% confidence interval, 0.76-0.94), with sensitivity of 79% and specificity of 80%, for the prediction of women who required cesarean delivery because of failure to progress. CONCLUSION: The differences in labor progress between vaginal and cesarean delivery have been illustrated objectively by serial intrapartum transperineal ultrasonographic assessment of fetal head descent. This tool is potentially predictive of women who will require cesarean delivery because of failure to progress.

Use of an electronic Partograph: feasibility and acceptability study in Zanzibar, Tanzania.

BACKGROUND: The ePartogram is a tablet-based application developed to improve care for women in labor by addressing documented challenges in partograph use. The application is designed to provide real-time decision support, improve data entry, and increase access to information for appropriate labor management. This study's primary objective was to evaluate the feasibility and acceptability of ePartogram use in resource-constrained clinical settings. METHODS: The ePartogram was introduced at three facilities in Zanzibar, Tanzania. Following 3 days of training, skilled birth attendants (SBAs) were observed for 2 weeks using the ePartogram to monitor laboring women. During each observed shift, data collectors used a structured observation form to document SBA comfort, confidence, and ability to use the ePartogram. Results were analyzed by shift. Short interviews, conducted with SBAs (n = 82) after each of their first five ePartogram-monitored labors, detected differences over time. After the observation period, in-depth interviews were conducted (n = 15). A thematic analysis of interview transcripts was completed. RESULTS: Observations of 23 SBAs using the ePartogram to monitor 103 women over 84 shifts showed that the majority of SBAs (87-91%) completed each of four fundamental ePartogram tasks-registering a client, entering first and subsequent measurements, and navigating between screens-with ease or increasing ease on their first shift; this increased to 100% by the fifth shift. Nearly all SBAs (93%) demonstrated confidence and all SBAs demonstrated comfort in using the ePartogram by the fifth shift. SBAs expressed positive impressions of the ePartogram and found it efficient and easy to use, beginning with first client use. SBAs noted the helpfulness of auditory reminders (indicating that measurements were due) and visual alerts (signaling abnormal measurements). SBAs expressed confidence in their ability to interpret and act on these reminders and alerts. CONCLUSIONS: It is feasible and acceptable for SBAs to use the ePartogram to support labor management and care. With structured training and support during initial use, SBAs quickly became competent and confident in ePartogram use. Qualitative findings revealed that SBAs felt the ePartogram improved timeliness of care and supported decision-making. These findings point to the ePartogram's potential to improve quality of care in resource-constrained labor and delivery settings.

Comparing Different Partograph Designs for Use in Standard Labor Care: A Pilot Randomized Trial.

Backgound Partographs are used in many labour settings to provide a pictorial overview of a woman's cervical dilation pattern in the first stage of labor and to alert clinicians to slow progress possibly requiring intervention. Recent reviews called for large trials to establish the efficacy of partographs to improve birth outcomes whilst highlighting issues of clinician compliance with use. Previous studies have also reported issues with participant recruitment related to concerns regarding the possibility of a longer labour. Objectives We sought to compare a standard partograph with an action line, to a newly designed partograph with a stepped line, to determine the feasibility of recruitment to a larger clinical trial. Methods A pragmatic, single-blind randomised trial wherein low-risk, nulliparous women in spontaneous labour at term were randomized to an action-line or stepped-line partograph. First stage labour management was guided by the allocated partograph. Primary outcomes included the proportion of eligible women recruited, reasons for failed recruitment and compliance with partograph use. Secondary outcomes included rates of intervention, mode of birth, maternal and neonatal outcomes. Results Of the 384 potentially eligible participants, 38% (149/384) were approached. Of these 77% (116/149) consented, with 85% (99/116) randomized, only nine women approached (6%) declined to participate. A further 9% (14/149) who were consented antenatally were not eligible at onset of labor and 7% (10/149) of women approached in the birth suite but did not meet the inclusion criteria. Compliance with partograph completion was 65% (action) versus 84% (dystocia line). Conclusions for Practice Participant recruitment to a larger randomized controlled trial comparing new labour management guidelines to standard care is feasible. Effective strategies to improve partograph completion compliance would be required to maintain trial fidelity.

Impact factors on fetal descent rates in the active phase of labor: a retrospective cohort study.

AIM: To assess fetal descent rates of nulliparous and multiparous women in the active phase of labor and to evaluate significant impact factors. METHODS: In a retrospective cohort study at the University Hospital of Zurich, Switzerland, we evaluated 6045 spontaneous vaginal deliveries with a singleton in vertex presentation between January 2007 and July 2014 at 34 0/7 to 42 0/7 gestational weeks. Median fetal descent rates and their 10th and 90th percentiles were assessed in the active phase of labor and different impact factors were evaluated. RESULTS: Fetal descent rates are exponentially increasing. Nulliparous women have slower fetal descent than multiparous women (P<0.001), ranging from 0 to 5.81 cm/h and from 0 to 15 cm/h, respectively. The total duration of fetal descent in labor is 5.42 h for nulliparous and 2.71 h for multiparous women. Accelerating impact factors are a lower fetal station, multiparity, increasing maternal weight and fetal occipitoanterior position, whereas epidural anesthesia decelerates fetal descent (P<0.001). CONCLUSIONS: Fetal descent is a hyperbolic increasing process with faster descent in multiparous women compared to nulliparous women, is highly inter individual and is associated with different impact factors. The diagnosis of labor arrest or prolonged labor should therefore be based on such rates as well as on individual evaluation of every parturient.

Impact factors on cervical dilation rates in the first stage of labor.

AIMS: To assess cervical dilation rates of nulliparous and multiparous women in the active first stage of labor and to evaluate significant impact factors. METHODS: In a retrospective cohort study between January 2007 and July 2014 at the University Hospital of Zurich in Switzerland, we analyzed 8378 women with singleton pregnancies in vertex presentation with a vaginal delivery at 34+0 to 42+5 gestational weeks. Median cervical dilation rates were calculated and different impact factors evaluated. RESULTS: Cervical dilation rates increase during labor progress with faster rates in multiparous compared with nulliparous women (P<0.001). Dilation rates exceed 1 cm/h at a dilatation of 6-7 cm, but are very individual. Accelerating impact factors are multiparity, a greater amount of cervical dilation and fetal occipitoanterior position, whereas the use of epidural anesthesia, a higher fetal weight and head circumference decelerate dilation (P<0.001). CONCLUSION: Cervical dilation is a hyperbolic increasing process, with faster dilation rates in multiparous compared to nulliparous women and a reversal point of labor around 6-7 cm, respectively. Besides, cervical dilation is highly individual and affected by several impact factors. The diagnosis of labor arrest or prolonged labor should therefore be based on such rates and on the individual evaluation of every woman.

Comparison of effacement curve with dilatation curve for prediction of labor progression.

AIM: This study was conducted to evaluate the ability of the effacement curve to predict fetal descent by comparing it to dilatation in order to improve the accuracy of the current partogram. METHOD: We conducted an observational study of women who were admitted for vaginal delivery at Mobini Hospital, Sabzevar, Iran in 2015. During labor, dilatation and effacement were plotted in different graphs and then their association with fetal descent was separately evaluated and compared. This assessment was performed in two groups: primipara and multipara. RESULTS: From 1750 individuals, 503 primiparous and 512 multiparous women were eligible for the study. An adjusted generalized estimating equations multivariable model showed both dilatation and effacement had a significant relationship with fetal descent either in primipara or multipara. In primipara, the prediction value of effacement equalled dilatation (ß,eff 0.29, P < 0.001; ß,dil 0.30, P < 0.001). In multipara, the prediction value of effacement was obviously higher than dilatation (ß,eff 0.45, P < 0.001; ß,dil 0.27, P < 0.001). The strength of effacement to predict labor in multipara was clearly greater than in primipara (ß,eff 0.45 and ß,eff 0.29, respectively). The strength of dilatation to predict labor in multipara was comparable to primipara (ß,dil 0.27 and ß,dil: 0.30, respectively). CONCLUSIONS: Regarding the acceptable predictive value of effacement, we believe considering effacement, dilatation and station curves altogether can improve the power of the existing partogram for the assessment of labor progression and detection of failure to progress.

A realist review of the partograph: when and how does it work for labour monitoring?

BACKGROUND: The partograph (or partogram) is recommended by the World Health Organisation (WHO), for monitoring labour wellbeing and progress. Concerns about limitations in the way the partograph is used in the clinical context and the potential impact on its effectiveness have led to this realist systematic review of partograph use. METHODS: This review aimed to answer two key questions, 1) What is it about the partograph that works (or does not work); for whom does it work; and in what circumstances? 2) What are the essential inputs required for the partograph to work? A comprehensive search strategy encompassed key databases; including papers of varying methodologies. Papers were selected for inclusion if the focus of the paper was the partograph and related to context, mechanism or outcome. Ninety five papers were included for data synthesis. Two authors completed data extraction and synthesis. RESULTS: The evidence synthesis relates the evidence to identified theories of health worker acceptability, health system support, effective referral systems, human resources and health worker competence, highlighting barriers and facilitators. CONCLUSIONS: This first comprehensive realist synthesis of the partograph, provides the international community of maternity clinicians with a picture of potential issues and solutions related to successful labour recording and management, which is also translatable to other monitoring approaches.

On predicting time to completion for the first stage of spontaneous labor at term in multiparous women.

BACKGROUND: Labor that progresses faster than anticipated may lead to unplanned out-of-hospital births. With the aim to improve planning of transportation to birthing institutions, this study investigated predictors of time to completion for the first stage of labor conditional on cervical opening (conditional time) in multiparous women at term. METHODS: We performed a retrospective analysis of partograms for women in Robson's group 3 who delivered at one hospital from 2003 to 2013. A generalized additive mixed model was fitted, accounting for possible non-linear relationships between the predictor variables and outcome, e.g. the time from each cervical measurement to full dilation, using multiple measurements for each woman. The following predictors were included: cervical dilation (cm), parity (1, 2, or ≥3 previous vaginal births), oxytocin infusion (no/yes), epidural (no/yes), maternal age (years), maternal height (cm), body mass index (BMI, kg/m2), birthweight (kg), spontaneous rupture of membranes (no/yes). A modified regression model with gestational age (days) instead of birthweight was used to predict conditional time to full cervical dilation for combinations of the most relevant predictors. RESULTS: A total of 1753 partograms were included in the analysis. The strongest predictors were birthweight, epidural and oxytocin use, and spontaneous rupture of membranes, along with cervical measurements. For birthweight, there was an almost 40% increase in time to full cervical dilation for each 1-kg increment. Conditional time was on average 23% longer in cases with epidural use and 53% longer in cases requiring oxytocin augmentation. Spontaneous rupture of the membranes shortened conditional time by 31%. Maternal age was not associated with the outcome, while increasing BMI and parity modestly reduced conditional time. CONCLUSIONS: Higher parity, lower fetal weight (gestational age), and spontaneous rupture of the membranes are associated with more rapid labor.

Inadequate fetal heart rate monitoring and poor use of partogram associated with intrapartum stillbirth: a case-referent study in Nepal.

BACKGROUND: Newborns are at the greatest risk for dying during the intrapartum period, including labor and delivery, and the first day of life. Fetal heart rate monitoring (FHRM) and partogram use to track labor progress are evidence-based techniques that can help to identify maternal and fetal risk factors so that these can be addressed early. The objective of this study was to assess health worker adherence to protocols for FHRM and partogram use during the intrapartum period, and to assess the association between adherence and intrapartum stillbirth in a tertiary hospital of Nepal. METHODS: A case-referent study was conducted over a 15-month period. Cases included all intrapartum stillbirths, while 20 % of women with live births were randomly selected on admission to make up the referent population. The frequency of FHRM and the use of partogram were measured and their association to intrapartum stillbirth was assessed using logistic regression analysis. RESULTS: During the study period, 4,476 women with live births were enrolled as referents and 136 with intrapartum stillbirths as cases. FHRM every 30 min was only completed in one-fourth of the deliveries, and labor progress was monitored using a partogram in just over half. With decreasing frequency of FHRM, there was an increased risk of intrapartum stillbirth; FHRM at intervals of more than 30 min resulted in a four-fold risk increase for intrapartum stillbirth (aOR 4.17, 95 % CI 2.0-8.7), and the likelihood of intrapartum stillbirth increased seven times if FHRM was performed less than every hour or not at all (aOR 7.38, 95 % CI 3.5-15.4). Additionally, there was a three-fold increased risk of intrapartum stillbirth if the partogram was not used (aOR 3.31, 95 % CI 2.0-5.4). CONCLUSION: The adherence to FHRM and partogram use was inadequate for monitoring intrapartum progress in a tertiary hospital of Nepal. There was an increased risk of intrapartum stillbirth when fetal heart rate was inadequately monitored and when the progress of labor was not monitored using a partogram. Further exploration is required in order to determine and understand the barriers to adherence; and further, to develop tools, techniques and interventions to prevent intrapartum stillbirth. CLINICAL TRIAL REGISTRATION: ISRCTN97846009 .

Prevention of primary caesarean delivery: comprehensive management of dystocia in nulliparous patients at term.

PURPOSE: Dystocia is the leading indication for primary caesarean sections. Our aim is to compare two approaches in the management of dystocia in labor in nulliparous women with a singleton fetus in cephalic presentation at term in spontaneous or induced labor. METHODS: Prospective cohort study. Four hundred and nineteen consecutive patients were divided into two groups: the standard management group (SM), in acceleration of labor was commenced at the "action line" in the case of arrested or protracted labor, and the comprehensive management group (CM) in which arrested or protracted labor was considered as a warning sign promoting further diagnostic assessment prior to considering intervention. RESULTS: Caesarean sections rate was 22.2 % in the SM group (216 patients) and 10.3 % in the CM group (203 patients) (p = 0.001). The rate of oxytocin use decreased from 33.3 % in SM group to 13.8 % in the CM group (p < 0.0005). The rate of amniotomy decreased from 41.7 % in the SM group to 7.4 % in the CM group (p < 0.0005). The percentage of newborns with 5-min Apgar score <7 and/or umbilical cord arterial pH ≤ 7.00 decreased from 2.3 % in SM cohort to 0.5 % in CM cohort (p = ns). The average length of labor did not differ between the two groups of patients (264 vs 277 min; p = ns). CONCLUSION: Comprehensive management of dystocia enabled us to achieve a reduction in iatrogenic interventions in labor while maintaining good neonatal outcomes.

Misguided guidelines for managing labor.

In a recent review we expressed concerns about new guidelines for the assessment and management of labor recommended jointly by the American Congress of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM). These guidelines are based heavily on a new concept of how cervical dilatation and fetal descent progress, derived from the work of Zhang et al. In their Viewpoint article they have addressed, but not allayed, the concerns we described in our review. We assert that the dilatation curve promulgated by Zhang et al cannot be reconciled with direct clinical observation. Even if they were correct, however, it still does not follow that the ACOG/SMFM guidelines should recommend replacing the coherent system of identifying and managing labor aberrations described by Friedman. That system is grounded in well-established clinical principles based on decades of use and the objectively documented association of some labor abnormalities with poor fetal and maternal outcomes. Recommendations for new clinical management protocols should require the demonstration of superior outcomes through extensive, preferably prospective, assessment. Using untested guidelines for the management of labor may adversely affect women and children. Even if those guidelines were to reduce the currently excessive cesarean delivery rate, the price of that benefit is likely to be a trade-off in harm to parturients and their offspring. The nature and degree of that harm needs to be documented before considering adoption of the guidelines.

Statistical aspects of modeling the labor curve.

In a recent review by Cohen and Friedman, several statistical questions on modeling labor curves were raised. This article illustrates that asking data to fit a preconceived model or letting a sufficiently flexible model fit observed data is the main difference in principles of statistical modeling between the original Friedman curve and our average labor curve. An evidence-based approach to construct a labor curve and establish normal values should allow the statistical model to fit observed data. In addition, the presence of the deceleration phase in the active phase of an average labor curve was questioned. Forcing a deceleration phase to be part of the labor curve may have artificially raised the speed of progression in the active phase with a particularly large impact on earlier labor between 4 and 6 cm. Finally, any labor curve is illustrative and may not be instructive in managing labor because of variations in individual labor pattern and large errors in measuring cervical dilation. With the tools commonly available, it may be more productive to establish a new partogram that takes the physiology of labor and contemporary obstetric population into account.

Perils of the new labor management guidelines.

Recent guidelines issued jointly by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine for assessing labor progress differ substantially from those described initially by Friedman, which have guided clinical practice for decades. The guidelines are based on results obtained from new and untested methods of analyzing patterns of cervical dilatation and fetal descent. Before these new guidelines are adopted into clinical practice, the results obtained by these unconventional analytic approaches should be validated and shown to be superior, or at least equivalent, to currently accepted standards. The new guidelines indicate the patterns of labor originally described by Friedman are incorrect and, further, are inapplicable to modern obstetric practice. We contend that the original descriptions of normal and abnormal labor progress, which were based on direct clinical observations, accurately describe progress in dilatation and descent, and that the differences reported more recently are likely attributable to patient selection and the potential inaccuracy of very high-order polynomial curve-fitting methods. The clinical evaluation of labor is a process of serially estimating the likelihood of a safe vaginal delivery. Because many factors contribute to that likelihood, such as cranial molding, head position and attitude, and the bony architecture and capacity of the pelvis, graphic labor patterns should never be used in isolation. The new guidelines are based heavily on unvalidated notions of labor progress and ignore clinical parameters that should remain cornerstones of intrapartum decision-making.