Differential HBV replicative markers and covalently closed circular DNA transcription in immune-active chronic hepatitis B with and without HBeAg.

BACKGROUND AND AIMS: Molecular processes driving immune-active chronic hepatitis B (CHB) with and without hepatitis B e antigen (HBeAg) remain incompletely understood. This study aimed to investigate expression profiles of serum and intrahepatic HBV markers and replicative activity of HBV in CHB patients with or without HBeAg. METHODS: This study recruited 111 untreated immune-active CHB (60 HBeAg-positive and 51 HBeAg-negative) patients and quantified intrahepatic covalently closed circular DNA (cccDNA), pre-genomic RNA (pgRNA), total HBV DNA (tDNA), and replicative intermediates as well as serum HBV markers (HBV DNA, hepatitis B surface antigen, hepatitis B core-related antigen). Correlations between HBV markers and clinico-virological factors influencing expression levels of HBV markers were analysed. RESULTS: Levels of all serum markers and intrahepatic cccDNA/tDNA as well as cccDNA transcriptional activity and virion productivity were significantly reduced in HBeAg-negative patients compared to those in HBeAg-positive patients. Additionally, correlations between intrahepatic cccDNA/pgRNA and serum markers were impaired in HBeAg-negative individuals. Aminotransferase levels were positively correlated with cccDNA transcriptional activity in HBeAg-positive patients, but not in HBeAg-negative patients. Notably, among HBeAg-positive patients, there was a progressive decline in pgRNA level, transcriptional activity, and serum HBV markers as liver fibrosis advanced, which was not observed in HBeAg-negative patients. CONCLUSIONS: HBeAg loss is correlated with diminished intrahepatic HBV reservoirs and cccDNA transcription, leading to decreased serum HBV marker levels. Circulating HBV markers are not reliable indicators of intrahepatic HBV replicative activity for HBeAg-negative patients. Our findings reveal distinct disease phenotypes between immune-active CHB with and without HBeAg, highlighting the need to establish optimal surrogate biomarkers that can accurately mirror intrahepatic viral activity to aid in decision-making for antiviral therapy for immune-active CHB.

Effect of Pethidine Injection on the Duration of Labor and Pregnancy Outcomes: A Retrospective Cohort Study.

Background and Objectives: Long and ineffective labor causes hardships for mothers and doctors and increases the rate of cesarean sections and medical comorbidities. Several factors contribute to effective and less painful labor, including maternal age, parity, fetal characteristics, and the medications or procedures that obstetricians use for labor. We aimed to study the factors that affect labor duration and identify those that make labor more effective. Materials and Methods: This retrospective study included 141 patients who underwent normal vaginal deliveries at the Daegu Catholic University Medical Center between April 2013 and April 2022. Among the 141 patients, 44 received pethidine intravenously, 88 received oxytocin intravenously, and 64 received epidural anesthesia. The duration of the active phase and second stage of labor were recorded according to the findings of a manual examination of the cervix and continuous external electronic monitoring. We analyzed maternal and neonatal medical records and performed binomial logistic regression to identify the factors associated with a shorter active phase of labor. The clinical outcomes in mothers and neonates were also evaluated. Results: Among the various clinical factors, multiparity (odds ratio of parity 0.325) and the use of pethidine (odds ratio 2.906) were significantly associated with shortening the active phase of labor to less than 60 min. The use of epidural anesthesia or oxytocin was not significantly associated with reducing the active phase of labor. When patients were divided into two groups based on whether a pethidine injection had been used during labor, the duration of the active phase was shorter in the pethidine injection group than in the control group for both nulliparas and multiparas. No significant differences in the duration of the second stage of labor were observed between the pethidine injection and control groups. There were no significant differences in pregnancy outcomes, including the need for mechanical ventilation of neonates, Apgar scores, neonatal intensive care unit admissions, number of precipitous deliveries, maternal adverse side effects of drugs, or duration of maternal hospitalization between the two groups. Conclusions: Pethidine can be safely administered to women during labor to help reduce the duration of the active phase by promoting dilatation of the cervix and preventing complications that may result from prolonged labor. Pethidine may be helpful, especially for those who cannot receive epidural anesthesia or who cannot afford it. However, large-scale randomized controlled studies are required to evaluate the efficacy and safety of this drug during labor. Furthermore, it would be helpful if various studies were conducted depending on the timing of administration and indications for delivery.

The active phase of labor.

The active phase of labor begins at various degrees of dilatation when the rate of dilatation transitions from the relatively flat slope of the latent phase to a more rapid slope. No diagnostic manifestations demarcate its onset, other than accelerating dilatation. It ends with apparent slowing of dilatation, a deceleration phase, which is usually short in duration and frequently undetected. Several aberrant labor patterns can be detected during the active phase, including protracted dilatation, arrest of dilatation, prolonged deceleration phase and failure of descent. Underlying factors may include cephalopelvic disproportion, excessive neuraxial block, poor uterine contractility, fetal malpositions, malpresentations, uterine infection, maternal obesity, advanced maternal age and previous cesarean delivery. When an active-phase disorder is identified, cesarean delivery is justifiable if there is compelling clinical evidence of disproportion. A prolonged deceleration disorder is strongly associated with disproportion and second stage abnormalities. Shoulder dystocia may occur if vaginal delivery eventuates. This review discusses several issues raised by the introduction of new clinical practice guidelines for labor management.

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.

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.

The evolution of the labor curve and its implications for clinical practice: the relationship between cervical dilation, station, and time during labor.

The assessment of labor progress is germane to every woman in labor. Two labor disorders-arrest of dilation and arrest of descent-are the primary indications for surgery in close to 50% of all intrapartum cesarean deliveries and are often contributing indications for cesarean deliveries for fetal heart rate abnormalities. Beginning in 1954, the assessment of labor progress was transformed by Friedman. He published a series of seminal works describing the relationship between cervical dilation, station of the presenting part, and time. He proposed nomenclature for the classification of labor disorders. Generations of obstetricians used this terminology and normal labor curves to determine expected rates of dilation and fetal descent and to decide when intervention was required. The analysis of labor progress presents many mathematical challenges. Clinical measurements of dilation and station are imprecise and prone to variation, especially for inexperienced observers. Many interrelated factors influence how the cervix dilates and how the fetus descends. There is substantial variability in when data collection begins and in the frequency of examinations. Statistical methods to account for these issues have advanced considerably in recent decades. In parallel, there is growing recognition among clinicians of the limitations of using time alone to assess progress in cervical dilation in labor. There is wide variation in the patterns of dilation over time and most labors do not follow an average dilation curve. Reliable assessment of labor progression is important because uncertainty leads to both over-use and under-use of cesarean delivery and neither of these extremes are desirable. This review traces the evolution of labor curves, describes how limitations are being addressed to reduce uncertainty and to improve the assessment of labor progression using modern statistical techniques and multi-dimensional data, and discusses the implications for obstetrical practice.

Cervical dilatation at diagnosis of active phase of labour determines the mode of delivery and peripartum outcomes: a retrospective study in a single tertiary centre in Malaysia.

BACKGROUND: There is an increasing trend of Caesarean section rate in Malaysia. Limited evidence demonstrated the benefits of changing the demarcation of the active phase of labour. METHODS: This was a retrospective study of 3980 singletons, term pregnancy, spontaneous labouring women between 2015 and 2019 comparing outcomes between those with cervical dilation of 4 versus 6 cm at diagnosis of the active phase of labour. RESULTS: A total of 3403 (85.5%) women had cervical dilatation of 4 cm, and 577 (14.5%) at 6 cm upon diagnosis of the active phase of labour. Women in 4 cm group were significantly heavier at delivery (p = 0.015) but significantly more multiparous women were in 6 cm group (p < 0.001). There were significantly fewer women in the 6 cm group who needed oxytocin infusion (p < 0.001) and epidural analgesia (p < 0.001) with significantly lower caesarean section rate (p < 0.001) done for fetal distress and poor progress (p < 0.001 both). The mean duration from diagnosis of the active phase of labour until delivery was significantly shorter in the 6 cm group (p < 0.001) with lighter mean birth weight (p = 0.019) and fewer neonates with arterial cord pH < 7.20 (p = 0.047) requiring neonatal intensive care unit admissions (p = 0.01). Multiparity (AOR = 0.488, p < 0.001), oxytocin augmentation (AOR = 0.487, p < 0.001) and active phase of labour diagnosed at 6 cm (AOR = 0.337, p < 0.001) reduced the risk of caesarean delivery. Caesarean delivery increased the risk of neonatal intensive care admission by 27% (AOR = 1.73, p < 0.001). CONCLUSIONS: Active phase of labour at 6 cm cervical dilatation is associated with reduced primary caesarean delivery rate, labour intervention, shorter labour duration and fewer neonatal complications.

Prediction model for labour dystocia occurring in the active phase.

To establish and verify a model for labour dystocia occurring in the active phase, this study retrospectively analysed the clinical data of primiparas with singleton cephalic full-term foetuses, who had delivered after a trial of labour. The Chi-square test, t-test, Mann-Whitney U test and multivariate logistic regression analysis were used for statistical analysis. Based on the model a nomogram was established using the R programming language. Multivariate logistic regression analysis showed that the foetal abdominal circumference, premature rupture of membranes (PROM), prolonged latent phase, foetal station and foetal position at the early stage of the active phase were independent factors influencing labour dystocia occurring in the active phase. The established model could effectively and accurately support clinicians in the early identification of labour dystocia to improve maternal and infant outcomes.Impact statementWhat is already known on this subject? Labour dystocia occurring during the active phase of the first stage, is the most commonly diagnosed as labour aberration. Previous studies have suggested that maternal age, body mass index, macrosomia and abnormal foetal position are the independent risk factors for labour dystocia. However, only the risk factors were reported, and few prediction models were established.What do the results of this study add? This study uses data in the real world to establish a prediction model of full-term singleton primipara with labour dystocia occurring in the active phase by logistic regression analysis. Foetal abdomen circumference, PROM, prolonged latent phase, the foetal station and foetal position at the early stage of the active phase are independent factors influencing labour dystocia that occurs in the active phase. In addition, a nomogram is established as a visual graph to predict the probability of it.What are the implications of these findings for clinical practice and/or further research? The nomogram based on the predictive model discarded complicated calculations and presented an easy visual graph-based method to predict the probability of labour dystocia occurring in the active phase. It helps to introduce interventions that could reduce the CS rate and occurrence of adverse maternal and foetal outcomes to ensure the safety of mothers and infants.

Abundant Dislocation Layered Double Hydroxides Synthesis by Molten Salt with Bound Water Boosting Oxygen Evolution.

Optimizing the adsorption free energy and promoting the active phase transition to further enhance the oxygen evolution reaction (OER) activity remain significant challenges. The adsorption free energy can be optimized by modulating the electronic structure and adjusting the crystal configuration. Meanwhile, the transformation of the active phase can be promoted by introducing strain energy. The theoretical calculations are conducted to verify the rational envisage. However, it is still a great obstacle to introducing strain into the electrocatalysts and avoiding destruction. The stress field caused by dislocation can realize both of the above. Hence, the molten salt with the bound water method is proposed and the abundant dislocation layered double hydroxides (D-NiFe LDH) are constructed. The in situ characterizations further verify the dislocations significantly affect the generation of the active phase and the state of electronic structure. Consequently, the D-NiFe LDH exhibits outstanding OER activity and obtains 10 mA cm-2 , only requiring 199 mV overpotential with fabulous stability (100 mA cm-2 more than 24 h). The work paves a new avenue for the rational introduction dislocations to optimize the crystal configuration and boost the active phase formation, significantly enhancing the OER performance.

Sonographic evaluation of the fetal head position and attitude during labor.

Fetal malpresentation, malposition, and asynclitism are among the most common determinants of a protracted active phase of labor, arrest of dilatation during the first stage, and arrest of descent in the second stage. The diagnosis of these conditions is traditionally based on vaginal examination, which is subjective and poorly reproducible. Intrapartum sonography has been demonstrated to yield higher accuracy than vaginal examination in characterizing fetal malposition, and some guidelines endorse its use for the verification of the occiput position before performing an instrumental delivery. It is also useful for the objective diagnosis of the malpresentation or asynclitism of the fetal head. According to our experience, the sonographic assessment of the head position in labor is simple to perform also for clinicians with basic ultrasound skills, whereas the assessment of malpresentation and asynclitism warrants a higher level of expertise. When clinically appropriate, the fetal occiput position can be easily ascertained using transabdominal sonography combining the axial and the sagittal planes. With the transducer positioned on the maternal suprapubic region, the fetal head can be visualized, and landmarks including the fetal orbits, the midline, and the occiput itself with the cerebellum and the cervical spine (depending on the type of fetal position) can be demonstrated below the probe. Sinciput, brow, and face represent the 3 "classical" variants of cephalic malpresentation and are characterized by a progressively increasing degree of deflexion from vertex presentation. Transabdominal sonography has been recently suggested for the objective assessment of the fetal head attitude when a cephalic malpresentation is clinically suspected. Fetal attitude can be evaluated on the sagittal plane with either a subjective or an objective approach. Two different sonographic parameters such as the occiput-spine angle and the chin-chest angle have been recently described to quantify the degree of flexion in fetuses in non-occiput-posterior or occiput-posterior position, respectively. Finally, although clinical examination still represents the mainstay of diagnosis of asynclitism, the use of intrapartum sonography has been shown to confirm the digital findings. The sonographic diagnosis of asynclitism can be achieved in expert hands using a combination of transabdominal and transperineal sonography. At suprapubic sonography on the axial plane only, 1 orbit can be visualized (squint sign) while the sagittal suture appears anteriorly (posterior asynclitism) or posteriorly (anterior asynclitism) displaced. Eventually the transperineal approach does not allow the visualization of the cerebral midline on the axial plane if the probe is perpendicular to the fourchette. In this expert review we summarize the indications, technique, and clinical role of intrapartum sonographic evaluation of fetal head position and attitude.

Development and validation of a predictive model to identify the active phase of labor.

BACKGROUND: The diagnosis of the active phase of labor is a crucial clinical decision, thus requiring an accurate assessment. This study aimed to build and to validate a predictive model, based on maternal signs and symptoms to identify a cervical dilatation ≥4 cm. METHODS: A prospective study was conducted from May to September 2018 in a II Level Maternity Unit (development data), and from May to September 2019 in a I Level Maternity Unit (validation data). Women with singleton, term pregnancy, cephalic presentation and presence of contractions were consecutively enrolled during the initial assessment to diagnose the stage of labor. Women < 18 years old, with language barrier or induction of labor were excluded. A nomogram for the calculation of the predictions of cervical dilatation ≥4 cm on the ground of 11 maternal signs and symptoms was obtained from a multivariate logistic model. The predictive performance of the model was investigated by internal and external validation. RESULTS: A total of 288 assessments were analyzed. All maternal signs and symptoms showed a significant impact on increasing the probability of cervical dilatation ≥4 cm. In the final logistic model, "Rhythm" (OR 6.26), "Duration" (OR 8.15) of contractions and "Show" (OR 4.29) confirmed their significance while, unexpectedly, "Frequency" of contractions had no impact. The area under the ROC curve in the model of the uterine activity was 0.865 (development data) and 0.927 (validation data), with an increment to 0.905 and 0.956, respectively, when adding maternal signs. The Brier Score error in the model of the uterine activity was 0.140 (development data) and 0.097 (validation data), with a decrement to 0.121 and 0.092, respectively, when adding maternal signs. CONCLUSION: Our predictive model showed a good performance. The introduction of a non-invasive tool might assist midwives in the decision-making process, avoiding interventions and thus offering an evidenced-base care.

Comparison the effect of Swedish massage and interferential electrical stimulation on labor pain and childbirth experience in primiparous women: a randomized controlled clinical trial.

BACKGROUND: Since mothers are more inclined toward non-pharmacological labor pain management methods, this study aimed to compare the effect of interferential electrical stimulation (IES) and Swedish massage (SM) on labor pain and childbirth experience (primary outcomes) and childbirth satisfaction, duration of active phase and side effects (secondary outcomes) in primiparous women. METHODS: This randomized controlled trial was performed on 90 primiparous women. Participants were randomly assigned into three groups through the block randomization method. The SM group received two massage techniques of effleurage and petrissage, on T10-L1 and S2-S4 at cervical dilatation of 4 and 8-10 cm. The IES group received electrical stimulation in a similar way to SM group, with a base frequency of 4000 Hz and a pulse frequency of 80-120 Hz by a physiotherapist. Control group received only routine care. RESULTS: The mean pain was significantly lower in the SM group (adjusted mean difference (AMD) - 0.86; 95% confidence interval (95% CI) - 1.60 to - 0.11) and the IES group (AMD - 0.95; 95% CI - 1.70 to - 0.21) compared to the control group. The mean score of childbirth experience was significantly higher in the SM (MD 5.63; 95% CI 2.15-9.11) and IES (MD 3.66; 95% CI 0.18-7.14) group compared to the control group. The mean childbirth satisfaction in the SM (p = 0.003) and IES (p = 0.046) groups was significantly higher than the control group; and duration of the active phase of labor was significantly lower (p < 0.001) than the control group. No serious side effects were occurred in none of the groups. CONCLUSION: SM and IES are safe methods that can significantly reduce pain and duration of active phase and improve the experience and satisfaction of childbirth.

Evaluating the effect of nipple stimulation during labour on labour progression in term pregnant women.

This study aimed to assess the effect of nipple stimulation during labour on duration of latent and active phases of labour in the term pregnant women. Pregnant women (222) were divided into two groups of nipple stimulation and control. Duration of latent and active phases of labour, the number of women treated with oxytocin, rate of caesarean section (C-section) and foetal outcomes were compared. The median of the latent phase duration of labour in the intervention and control groups was 3.2 (1.3-6.3) and 4.8 (0.8-3.0) h, respectively (p = .008); however, the median of active phase duration was 2.3 (1.4-3.0) in the intervention group and 2.5 (2.0-3.3) in control group, which was not significantly different (p = .249). Additionally, the number of women treated with oxytocin in nipple stimulation group was significantly (p = .001) less than the control group. More studies are needed to evaluate optimum frequency and duration of nipple stimulation during labour.IMPACT STATEMENTWhat is already known on this subject? In limited studies, nipple stimulation is considered as a low-complication method for stimulating labour at onset.What do the results of this study add? Nipple stimulation can be applied during labour for accelerating latent phase and reducing oxytocin infusion.What are the implications of these findings for clinical practice and/or further research? Nipple stimulation can be applied as a non-pharmacological and non-invasive method allowing patient to control her own labour progression more effectively.

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.

When does fetal head rotation occur in spontaneous labor at term: results of an ultrasound-based longitudinal study in nulliparous women.

BACKGROUND: Improved information about the evolution of fetal head rotation during labor is required. Ultrasound methods have the potential to provide reliable new knowledge about fetal head position. OBJECTIVE: The aim of the study was to describe fetal head rotation in women in spontaneous labor at term using ultrasound longitudinally throughout the active phase. STUDY DESIGN: This was a single center, prospective cohort study at Landspitali - The National University Hospital of Iceland, Reykjavík, Iceland, from January 2016 to April 2018. Nulliparous women with a single fetus in cephalic presentation and spontaneous labor onset at ≥37 weeks' gestation were eligible. Inclusion occurred when the active phase could be clinically established by labor ward staff. Cervical dilatation was clinically examined. Fetal head position and subsequent rotation were determined using both transabdominal and transperineal ultrasound. Occiput positions were marked on a clockface graph with 24 half-hour divisions and categorized into occiput anterior (≥10- and ≤2-o'clock positions), left occiput transverse (>2- and <4-o'clock positions), occiput posterior (≥4- and ≤8 o'clock positions), and right occiput transverse positions (>8- and <10-o'clock positions). Head descent was measured with ultrasound as head-perineum distance and angle of progression. Clinical vaginal and ultrasound examinations were performed by separate examiners not revealing the results to each other. RESULTS: We followed the fetal head rotation relative to the initial position in the pelvis in 99 women, of whom 75 delivered spontaneously, 16 with instrumental assistance, and 8 needed cesarean delivery. At inclusion, the cervix was dilated 4 cm in 26 women, 5 cm in 30 women, and ≥6 cm in 43 women. Furthermore, 4 women were examined once, 93 women twice, 60 women 3 times, 47 women 4 times, 20 women 5 times, 15 women 6 times, and 3 women 8 times. Occiput posterior was the most frequent position at the first examination (52 of 99), but of those classified as posterior, most were at 4- or 8-o'clock position. Occiput posterior positions persisted in >50% of cases throughout the first stage of labor but were anterior in 53 of 80 women (66%) examined by and after full dilatation. The occiput position was anterior in 75% of cases at a head-perineum distance of ≤30 mm and in 73% of cases at an angle of progression of ≥125° (corresponding to a clinical station of +1). All initial occiput anterior (19), 77% of occiput posterior (40 of 52), and 93% of occiput transverse positions (26 of 28) were thereafter delivered in an occiput anterior position. In 6 cases, the fetal head had rotated over the 6-o'clock position from an occiput posterior or transverse position, resulting in a rotation of >180°. In addition, 6 of the 8 women ending with cesarean delivery had the fetus in occiput posterior position throughout the active phase of labor. CONCLUSION: We investigated the rotation of the fetal head in the active phase of labor in nulliparous women in spontaneous labor at term, using ultrasound to provide accurate and objective results. The occiput posterior position was the most common fetal position throughout the active phase of the first stage of labor. Occiput anterior only became the most frequent position at full dilatation and after the head had descended below the midpelvic plane.

Spontaneous labor curve based on a retrospective multi-center study in Japan.

AIM: In Japan, the criteria of the latent and active phases of the first stage of labor have not been decided. The Japan Society of Obstetrics and Gynecology (JSOG) Perinatal Committee conducted a study to construct a spontaneous labor curve in order to determine the point of onset of the active phase. METHODS: The participants were women who had spontaneous deliveries at four health facilities in Japan between September 1, 2011, and September 31, 2019. Spontaneous delivery was defined as the spontaneous onset of labor at term (37 weeks, 0 days to 41 weeks, 6 days) with vaginal delivery of a mature fetus in a cephalic position without uterotonic agents or epidural analgesia. The time points for each "cm" of dilation were collected starting from the time of full dilation retrogradely. The relationship between time since labor onset and cervical dilation was expressed as a curve using a smoothing B-spline. RESULTS: A total of 4215 primiparous and 5266 multiparous women were included in this study. The spontaneous labor curve showed that in both primiparous and multiparous women, labor progress was slow until 5 cm cervical dilation, accelerating between 5 and 6 cm dilation, and steadily progressed after 6 cm dilation. CONCLUSION: We propose that the active phase of the first stage of labor be defined as starting at 5 cm dilation of the cervix, and that it be divided into an acceleration phase (5-6 cm dilation) and a maximal phase (>6 cm dilation).

Progression of the first stage of labour, in low risk nulliparas in a South Asian population: a prospective observational study.

We compared the labour pattern in the active phase of labour, defined at 4 cm versus 6 cm cervical dilatation, in a South Asian population. This was a prospective observational study where 500 low risk nulliparous women were recruited. Our aim was to study, the average labour pattern curve of all parturients. Mean duration of the active phase from 4 to 10 cm was 5.12 ± 2.10 hours and from 6 to 10 cm was 2.79 ± 1.72 hours. The 95th percentile values suggests that it takes 5-6 hours to progress from 4 to 6 cm and again 5-6 hours from 6 to 10 cm. The minimum labour progression rate can be as low as 0.5 cm/hour with vaginal delivery (VD) still being achieved. The slope of labour curve steepens after 6 cm, suggesting 6 cm as the onset of the active phase. Allowing labour to continue for a longer period before 6 cm of cervical dilation may reduce the rate of unnecessary intrapartum intervention and caesarean section (CS) for labour dystocia.Impact StatementWhat is already known on this subject? Friedman's definitions of normal labour and abnormal labour are widely accepted in current obstetric practises. Friedman's normal dilatation rate of 1 cm/h that is universally accepted is becoming questionable in our current obstetric population because of escalating rates of unnecessary labour interventions like oxytocin augmentation and CS.What the results of this study add? The rule of 1 cm/hour of labour progression cannot be applied to every woman and inappropriate interventions should be withheld until labour progression does falls below 0.5 cm/hour.What the implications are of these findings for clinical practice and/or further research? Six centimetres rather than 4 cm of cervical dilatation is a more appropriate landmark for the start of the active phase. Allowing labour to continue for a longer period before 6 cm of cervical dilation may reduce the rate of unnecessary intrapartum interventions and CS for labour dystocia.

"New or not-so-new" labor management practices and cesarean delivery for arrest of progress.

BACKGROUND: Because nearly one-third of births in the United States are now achieved by cesarean delivery, comprising more than 1.27 million women each year, national organizations have recently published revised guidelines for the management of labor. These new guidelines stipulate that labor arrest should not be diagnosed unless ≥6 cm cervical dilatation has been reached or labor has been stimulated for at ≥6 hours. OBJECTIVE: To determine the cervical dilatation and hours of labor stimulation prior to cesarean delivery for arrest of dilatation. MATERIALS AND METHODS: Between January 1, 1999, andDecember 31, 2000, a prospective observational study of all primary cesarean deliveries was conducted at 13 university centers comprising the Eunice Kennedy Shriver National Institute for Child Health and Human Development, Maternal-Fetal Medicine Units Network. This secondary analysis includes all live-born, singleton, nonanomalous, cephalic gestations delivered by primary cesarean delivery at ≥37 weeks. A cesarean delivery was considered to have been performed for arrest of dilatation if the indication for the procedure was failure to progress, cephalopelvic disproportion, or failed induction. Augmentation was defined as stimulation after spontaneous labor had been previously diagnosed. Analysis included both the latent and active phases of labor. The active phase of labor was diagnosed when cervical dilatation was ≥4 cm in the presence of uterine contractions. RESULTS: A total of 13,269 primary cesarean deliveries were available for analysis, 8,546 (65%) of which were performed for inadequate progress of labor with cervical dilatation recorded at the time of cesarean delivery. Of these cesarean deliveries for labor arrest, a total of 719 (8%) were performed in the latent phase of labor and 7827 (92%) were performed when cervical dilatation was ≥4 cm (active phase). Approximately two-thirds (n = =5876; 69%) received intrauterine pressure monitoring. A total of 5636 women (66% of those reaching the active phase of labor) had reached ≥6 cm cervical dilatation before cesarean delivery was performed. Moreover, 7440 (95%) of the 7827 women in active labor had ≥6 cm dilatation or had received labor stimulation ≥6 hours prior to cesarean delivery for arrest of dilatation. CONCLUSION: Women undergoing primary cesarean delivery for arrest of dilatation 15 years before the recommendations of the Obstetrics Care Consensus had received bona fide efforts to achieve adequate labor consistent with the recommendations of the Consensus. Because 95% of these women had ≥6 cm dilatation or had received labor stimulation ≥6 hours prior to cesarean delivery for arrest of dilatation, these new recommendations are unlikely to change the cesarean delivery rates.

Variations in outcomes for women admitted to hospital in early versus active labour: an observational study.

BACKGROUND: There is no available evidence for the prevalence of early labour admission to hospital or its association with rates of intervention and clinical outcomes in Australia. The objectives of this study were to: estimate the prevalence of early labour admission in one hospital in Australia; compare rates of clinical intervention, length of hospital stay and clinical outcomes for women admitted in early (< 4 cm cervical dilatation) or active (≥4 cm) labour; and determine the impact of recent recommendations to define early labour as < 5 cm on the findings. METHODS: We conducted a retrospective cohort study using medical record data from a random sample of 1223 women from live singleton births recorded between July 2013 and December 2015. Analyses included women who had spontaneous onset of labour at ≥37 weeks gestation whilst not a hospital inpatient, who had not scheduled a caesarean section before labour onset or delivered prior to hospital admission. Associations between timing of hospital admission in labour and clinical intervention, outcomes and hospital stay were assessed using logistic regression. RESULTS: Between 32.4% (< 4 cm) and 52.9% (< 5 cm) of eligible women (N = 697) were admitted to hospital in early labour. After adjustment for potential confounders, women admitted in early labour (< 4 cm) were more likely to have their labour augmented by oxytocin (AOR = 3.57, 95% CI 2.39-5.34), an epidural (AOR = 2.27, 95% CI 1.51-3.41), a caesarean birth (AOR = 3.50, 95% CI 2.10-5.83), more vaginal examinations (AOR = 1.73, 95% CI = 1.53-1.95), and their baby admitted to special care nursery (AOR = 1.54, 95% CI = 1.01-2.35). Defining early labour as < 5 cm cervical dilatation produced additional significant associations with artificial rupture of membranes (AOR = 1.41, 95% CI = 1.02-1.95), assisted vaginal birth (AOR = 1.96, 95% CI = 1.12-3.41) neonatal resuscitation (AOR = 1.73, 95% CI = 1.01-2.99) and longer maternal hospital stay (AOR = 1.21, 95% CI = 1.04-1.40). CONCLUSIONS: Findings provide preliminary evidence that a notable proportion of labouring women are admitted in early labour and are more likely to experience several medical procedures, neonatal resuscitation and admission to special care nursery, and longer hospital stay.

The effect of maternal body mass index on duration of induced labor.

INTRODUCTION: Obese primiparous women with induction of labor are at high risk for a cesarean section. There are contradictory results regarding time in induced labor in relation to maternal body mass index (BMI). It is important to characterize the course of induced labor to prevent unnecessary cesarean section. We aimed to evaluate whether the duration of labor was associated with maternal BMI in primiparous women with induction of labor. MATERIAL AND METHODS: A national retrospective cohort study, including 15 259 primiparae with a single term pregnancy, admitted for induction of labor from January 2014 to August 2017. Data were obtained from the Swedish Pregnancy Registry. Cox regression analyses were used to illustrate the association between BMI and active labor and between BMI and time from admission until start of active labor. RESULTS: Duration of active labor was shorter in underweight women and prolonged in women with BMI ≥40 kg/m2 compared with women in other BMI classes, illustrated by Cox regression graphs (P < .001). The median durations of active labor in underweight women were 6.1 and 7.4 hours in women with BMI ≥40 kg/m2 . The time from admission until start of active labor increased with maternal BMI, illustrated by Cox regression graphs (P < .001) and the median duration increased from 12.9 hours in underweight women to 22.6 hours in women with BMI ≥40 kg/m2 . The cesarean section rate in active labor increased significantly with BMI (P < .001) from 7.4% in underweight women to 22.0% in women with BMI ≥40 kg/m2 . Obese and normal weight women had similar rates of spontaneous vaginal delivery (69.9% in the total study population). CONCLUSIONS: The duration of active labor was associated with maternal BMI for underweight women and women with BMI ≥40 kg/m2 . Although women with BMI ≥40 kg/m2 who reached the active phase of labor had the same chance for a spontaneous vaginal delivery as normal weight women, the duration of active labor and the cesarean section rate were increased. The time from admission until start of active labor increased successively with maternal BMI.