The use of bubble charts in analyzing second stage cesarean delivery rates.

BACKGROUND: The incidence of second stage cesarean delivery has been rising globally because of the failure or the anticipated difficulty of performing instrumental delivery. Yet, the best way to interpret the figure and its optimal rate remain to be determined. This is because it is strongly influenced by the practice of other 2 modes of birth, namely cesarean delivery performed before reaching the second stage and assisted vaginal birth during the second stage. In this regard, a bubble chart that can display 3-dimensional data through its x-axis, y-axis, and the size of each plot (presented as a bubble) may be a suitable method to evaluate the relationship between the rates of these 3 modes of births. OBJECTIVE: This study aimed to conduct an epidemiologic study on the incidence of second stage cesarean deliveries rates among >300,000 singleton term births in 10 years from 8 obstetrical units and to compare their second stage cesarean delivery rates in relation to their pre-second stage cesarean delivery rates and assisted vaginal birth rates using a bubble chart. STUDY DESIGN: The territory-wide birth data collected between 2009 and 2018 from all 8 public obstetrical units (labelled as A to H) were reviewed. The inclusion criteria were all singleton pregnancies with cephalic presentation that were delivered at term (≥37 weeks' gestation). Pre-second stage cesarean delivery rate was defined as all elective cesarean deliveries and those emergency cesarean deliveries that occurred before full cervical dilatation was achieved as a proportion of the total number of births. The second stage cesarean delivery rate and assisted vaginal birth rate were calculated according to the respective mode of delivery as a proportion of the number of cases that reached full cervical dilatation. The rates of these 3 modes of births were compared among the parity groups and among the 8 units. Using a bubble chart, each unit's second stage cesarean delivery rate (y-axis) was plotted against its pre-second stage cesarean delivery rate (x-axis) as a bubble. Each unit's second stage cesarean delivery to assisted vaginal birth ratio was represented by the size of the bubble. RESULTS: During the study period, a total of 353,434 singleton cephalic presenting term pregnancies were delivered in the 8 units, and 180,496 (51.1%) were from nulliparous mothers. When compared with the multiparous group, the nulliparous group had a significantly lower pre-second stage cesarean delivery rate (18.58% vs 21.26%; P<.001) but a higher second stage cesarean delivery rate (0.79% vs 0.22%; P<.001) and a higher assisted vaginal birth rate (17.61% vs 3.58%; P<.001). Using the bubble of their averages as a reference point in the bubble chart, the 8 units' bubbles were clustered into 5 regions indicating their differences in practice: unit B and unit H were close to the average in the center. Unit A and unit F were at the upper right corner with a higher pre-second stage cesarean delivery rate and second stage cesarean delivery rate. Unit D and unit E were at the opposite end. Unit C was at the upper left corner with a low pre-second stage cesarean delivery rate but a high second stage cesarean delivery rate, whereas unit G was at the opposite end. Unit C and unit G were also in the extremes in terms of pre-second stage cesarean delivery to assisted vaginal birth ratio (0.09 and 0.01, respectively). Although some units seemed to have very similar second stage cesarean delivery rates, their obstetrical practices were differentiated by the bubble chart. CONCLUSION: The second stage cesarean delivery rate must be evaluated in the context of the rates of pre-second stage cesarean delivery and assisted vaginal birth. A bubble chart is a useful method for analyzing the relationship among these 3 variables to differentiate the obstetrical practice between different units.

Implementation of sonopartogram: multicenter feasibility study.

OBJECTIVES: Well-established clinical practice for assessing progress in labor involves routine abdominal palpation and vaginal examination (VE). However, VE is subjective, poorly reproducible and painful for most women. In this study, our aim was to evaluate the feasibility of systematically integrating transabdominal and transperineal ultrasound assessment of fetal position, parasagittal angle of progression (psAOP), head-perineum distance (HPD) and sonographic cervical dilatation (SCD) to monitor the progress of labor in women undergoing induction of labor (IOL). We also aimed to determine if ultrasound can reduce women's pain during such examinations. METHODS: Women were recruited as they presented for IOL in three maternity units. Ultrasound assessments were performed in 100 women between 37 + 0 and 41 + 6 weeks' gestation. A baseline combined transabdominal and transperineal scan was performed, including assessment of fetal biometry, umbilical artery and fetal middle cerebral artery Doppler, amniotic fluid index, fetal spine and occiput positions, psAOP, HPD, SCD and cervical length. Intrapartum scans were performed instead of VE, unless there was a clinical indication to perform a VE, according to protocol. Participants were asked to indicate their level of pain by verbally giving a pain score between 0 and 10 (with 0 representing no pain) during assessment. Repeated measures data were analyzed using mixed-effect models to identify significant factors that affected the relationship between psAOP, HPD, SCD and mode of delivery. RESULTS: A total of 100 women were included in the study. Of these, 20% delivered by Cesarean section, 65% vaginally and 15% by instrumental delivery. There were no adverse fetal or maternal outcomes. A total of 223 intrapartum ultrasound scans were performed in 87 participants (13 women delivered before intrapartum ultrasound was performed), with a median of two scans per participant (interquartile range (IQR), 1-3). Of these, 76 women underwent a total of 151 VEs with a median of one VE per participant (IQR, 0-2), with no significant difference between vaginal- or Cesarean-delivery groups. After excluding those with epidural anesthesia during examination, the median pain score for intrapartum scans was 0 (IQR, 0-1) and for VE it was 3 (IQR, 0-6). Cesarean delivery was significantly associated with a slower rate of change in psAOP, HPD and SCD. CONCLUSIONS: Comprehensive transabdominal and transperineal ultrasound assessment can be used to assess progress in labor and can reduce the level of pain experienced during examination. Ultrasound assessment may be able to replace some transabdominal and vaginal examinations during labor. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Intrapartum ultrasound for cervical dilatation: Inter- and intra-observer agreement.

INTRODUCTION: Digital vaginal examination (DVE) is considered the standard of care for assessing labor progress and cervical dilatation. However, it may be painful and is a subjective method that can increase the risk of chorioamnionitis. Known inter- and intra-observer variability exists in measurements of cervical dilatation obtained digitally. However, little is known about the inter- and intra-observer variability when using intrapartum transperineal ultrasound (TPUS). Our objectives were to investigate the relationship between cervical dilatation as assessed by TPUS and DVE. To assess inter- and intra-observer variability in both single and repeated ultrasound assessments of cervical dilatation during active labor. MATERIAL AND METHODS: This single-center study was conducted at an inner-city maternity unit in London, UK. Nulliparous participants at term with a live, singleton fetus in cephalic presentation were recruited between May 2021 and November 2022. During active labor, TPUS was performed subsequent to DVE. Repeat ultrasound assessments were performed where feasible. Participants were in a supine position, with flexed hips and knees and with an empty bladder. The ultrasound transducer was placed transversely on the maternal perineum. The anteroposterior (AP) diameter of the cervix was measured, and two-dimensional (2D) cine-loop videos were analyzed to obtain accurate measurements. Data were excluded if the time difference between DVE and TPUS exceeded 60 min. RESULTS: Of the 206 participants who consented to the study, complete data were obtained from 110 participants, yielding 147 paired TPUS and DVE observations. Ninety-six participants were excluded. The absolute difference between TPUS and DVE assessments was 0 cm in 34% of the observations, 1 cm in 46.3%, and between 2 and 4 cm in 19.7%. The mean difference was -0.9 cm (intraclass correlation coefficient = 0.85; p < 0.001). Data from 30 participants, with 50 cervical dilatation measurements, were used to assess inter- and intra-observer variability. The mean difference for the first ultrasound assessment was 0.07 cm (95% limit of agreement = -0.96 to 1.10, p < 0.001), for inter-observer variability, and 0.01 cm (95% limit of agreement = -0.29 to 0.30; p < 0.001) for intra-observer variability. CONCLUSIONS: Assessment of the cervix with TPUS during active labor is feasible and shows a strong correlation with DVE measurements. The majority of ultrasound measurements yielded readings within 1 cm of the corresponding DVE values, demonstrating high intraclass correlation and good inter- and intra-observer agreement.

Self-Traction During Mechanical Cervical Dilatation, Acceptability, Feasibility and Satisfaction of its Application: A Pilot Study.

This study aims to measure acceptability, feasibility, and satisfaction with self-traction during mechanical cervical dilatation to induce labour and to explore its effects on pain and the process of labour and delivery. 60 parturients were randomly assigned to self-traction or regular traction. Participants completed questionnaires about sociodemographic characteristics, acceptability, and satisfaction. Self-traction participants reported significantly higher acceptability (P = 0.026), and adequacy (P = 0.018). They also reported satisfaction with the procedure. A group comparison regarding feasibility, pain, and the process of labour and delivery showed no significant difference. Self-traction is an acceptable and feasible intervention for full-term parturients.

Expectant management vs. cerclage in cases with prolapsed or visible membranes in the second trimester: is 24 weeks gestation threshold critical?

OBJECTIVES: The aim of this study was to compare the efficacy of cervical cerclage with spontaneous follow-up strategy on pregnancy duration and neonatal outcomes in women with visible or prolapsed fetal membranes. METHODS: Patients who were referred to a single tertiary care centre between 1st January 2017 and 31st December 2022 were included in this comparative, retrospective cohort study. Patients were divided into two groups, those undergoing cerclage and those followed with no-cerclage. The range of pregnancy weeks for cerclage is between 18th and 27+6 weeks. RESULTS: A total of 106 cases were reviewed and nine were excluded. Based on shared decision making, cervical cerclage was performed in 76 patients (78.3 %) and 21 patients (21.6 %) were medically treated in no-cerclage group if there was no early rupture of the fetal membranes. The gestational age at delivery was 29.8 ± 6 [median=30 (19-38)] weeks in the cerclage group and 25.8 ± 2.9 [median=25 (19-32)] weeks in the no-cerclage group (p=0.004). Pregnancy prolongation was significantly longer in the cerclage group compared to the no-cerclage group (55 ± 48.6 days [median=28 (3-138)] vs. 12 ± 17.9 days [median=9 (1-52)]; p<0.001). Take home baby rate was 58/76 (76.3 %) in cerclage group vs. 8/21 (38 %) in no-cerclage group. In the post-24 week cerclage group the absolute risk reduction for pregnancy loss was 50 % (95 % CI=21.7-78.2). CONCLUSIONS: Cervical cerclage applied before and after 24 weeks (until 27+6 weeks) increased take home baby rate in women with visible or prolapsed fetal membranes without increasing adverse maternal outcome when compared with no-cerclage group.

The association between the degree of cervical dilatation before ultrasound and physical examination indicated cerclage and subsequent neonatal outcomes.

INTRODUCTION: Preterm identification of cervical dilation in pregnant women leads to the application of emergency cervical cerclage with an expectation of achieving term delivery. However, this is not always feasible. Short- and long-term neonatal complications post-preterm birth pose a significant challenge. It is crucial to anticipate potential complications and understand the possibilities of postpartum development as they can be encountered. We aimed to evaluate the effect of the degree of cervical dilatation before ultrasound and physical examination-indicated cerclage in singleton pregnancies presenting with premature cervical dilatation with bulging fetal membranes (rescue cerclage) on subsequent neonatal outcomes. MATERIALS AND METHODS: In this retrospective clinical study, over a 10-year period between January 2009 and January 2019, 72 singleton pregnancies undergoing rescue cerclage were included and divided into two groups according to pre-cerclage cervical dilatation: Group 1 (n = 33) and Group 2 (n = 39) with cervical dilatation ≤3 cm and >3 cm, respectively. Latency period for pregnancy prolongation, gestational age at delivery, birth weight, and neonatal morbidity and mortality were compared across the groups. Logistic regression was used to delineate the independent effect of cervical dilatation at cerclage placement on neonatal mortality. RESULTS: Group 2 had a higher delivery rate at ≤28 weeks' gestation (p = 0.007) and lower birth weight (p = 0.002) compared to Group 1, with an increased mean latency period in Group 2 (90 ± 55 days versus 52 ± 54 days, p = 0.005). The newborn intensive care unit (NICU) requirement, respiratory distress syndrome (RDS), neonatal jaundice and sepsis, and retinopathy of prematurity (ROP) were more frequent in Group 2. Neonatal mortality rate was higher (52.6% versus 24.2%, p = 0.015) and intact survival was lower (23.1% versus 48.4%, p = 0.013) in Group 2, whereas rates of cerebral palsy (8% and 9%, respectively) were similar between the groups (p = 0.64). CONCLUSION: Advanced cervical dilatation (>3 cm) during physical examination-indicated cerclage in singleton pregnancies is associated with earlier delivery, leading to increased neonatal morbidity and mortality when compared with pregnancies having lesser degrees of cervical dilatation at cerclage. However, short-term poor neurological outcomes seem comparable.

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.

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.

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.

A force-measuring device combined with ultrasound-based elastography for assessment of the uterine cervix.

INTRODUCTION: In this feasibility study, we hypothesize that the evaluation of cervical biomechanical strength can be improved if cervical length measurement is supplemented with quantitative elastography, which is a technique based on conventional ultrasound elastography combined with a force-measuring device. Our aims were to: (a) develop a force-measuring device; (b) introduce a cervical elastography index (CEI) and a cervical strength index (CSI; defined as cervical length × CEI); (c) evaluate how these indexes assess the cervical softening that takes place during normal pregnancy; and (d) how these indexes predict the cervical dilatation time from 4 to 10 cm. MATERIAL AND METHODS: An electronic force-measuring device was mounted on the handle of the transvaginal probe, allowing for force measurement when conducting elastography. The study group concerned with normal cervical softening included 44 unselected pregnant women. Outcomes were CEI and CSI at different gestational ages. The study group for labor induction included 26 singleton term pregnant women admitted for labor induction. Outcome was defined as cervical dilatation time from 4 to 10 cm. Elastography measured the changes in mean gray value (intensity) during manual compressions. Region of interest was set within the anterior cervical lip. RESULTS: We found that the mean of all variables regarding cervical softening decreased from early to late pregnancy: ie cervical length from 34 to 29 mm, CEI from 0.17 to 0.11 N, and CSI from 5.9 to 3.1 N mm. Moreover, the cervical dilatation time during labor induction was associated with CEI, although not statistically significantly (area under the ROC curve of 0.67), but not with the Bishop score, the cervical length, or the CSI. CONCLUSIONS: We propose that quantitative elastography based on changes in the intensity of the B-mode ultrasound recording, in combination with a force-measuring device on the handle of the vaginal probe, deserves further investigation as an approach for evaluation of cervical biomechanical strength.

A randomised comparative study of sublingual and vaginal misoprostol for cervical priming before minor gynaecological procedures.

This study aimed to compare the effect of misoprostol using vaginal or sublingual routes on the non-pregnant uterine cervix prior to minor gynaecological procedures. One hundred and forty women were randomised 1:1 into two groups: A and B. Group A received misoprostol 400 mcg vaginally and pyridoxine 40 mg sublingually and Group B received misoprostol 400 mcg sublingually and pyridoxine 40 mg vaginally 4 h prior to procedure. The outcomes studied were maximum size of Hegar's dilator that could be inserted into the cervix without any resistance, ease of dilatation, need and time required for further dilatation, side effects and complications. Baseline cervical dilatation was significantly more in Group A than Group B. Need for further dilatation and time required for further dilatation were also significantly less in Group A than Group B. Thus, we conclude that vaginal misoprostol is more effective than sublingual misoprostol in cervical priming before minor gynaecological procedures. Clinical Trial Registration Number: www.ctri.nic.in; CTRI/2018/07/015080 IMPACT STATEMENTWhat is already known on this subject? Cervical priming has been shown to result in shorter operative time, easier mechanical dilatation, reduced incidence of complications and blood loss when used prior to surgical abortion and has been recommended as a standard practice in various national and international guidelines for safe abortion practices. Misoprostol has many advantages over other ripening agents like osmotic dilators, other prostaglandins and mifepristone. Misoprostol can be given through oral, sublingual, vaginal, buccal and rectal routes. Use of misoprostol has been found to improve cervical dilatation, reduce need of further dilatation and ease of dilatation without many complications when compared to placebo for cervical priming of non-pregnant cervix. Studies comparing vaginal and sublingual routes have shown no significant difference for cervical ripening in pregnant women.What the results of this study add? We found that vaginal misoprostol for cervical priming was more effective than sublingual misoprostol in reaching a higher baseline cervical dilatation, with reduced need and time required for further dilatation before minor gynaecological procedures, although the ease of dilatation was similar in both groups. This effect of vaginal misoprostol was more marked in premenopausal women.What the implications are of these findings for clinical practice and/or further research? The results of our study are at variance with other studies done on use of misoprostol via the vaginal or sublingual routes, and hence it is imperative that large multi-center studies be performed to bring about consensus on the topic.

A comparative clinical trial of vaginal misoprostol versus intracervical normal saline infiltration as a cervical ripening agent at time of hysteroscopy.

Cervical status has a great impact on the duration and success of its dilatation especially during hysteroscopy, so cervical ripening employed before the procedure can increase the success rate and minimize the complications. AIM: To compare the efficacy of vaginal misoprostol and intracervical normal saline infiltration as cervical ripening agents. METHODS: A randomized comparative clinical trial had been conducted in AL Yarmouk Teaching Hospital involving two methods for cervical ripening before the hysteroscopic procedure. One Hundred women were enrolled in the study, fifty of them were those who used preoperative vaginal misoprostol and the other fifty patients were those who had been submitted to intracervical normal saline infiltration during surgery. Basal cervical dilatation, time to achieve 8 mm cervical dilatation, difficulties, and complications encountered during the procedure were evaluated and compared for both groups. RESULTS: The participants had been admitted for hysteroscopy for the following indications: Abnormal uterine bleeding, missed loop, infertility, polypectomy, endometrial resection, and myomectomy. Regarding operative findings, the basal cervical dilatation was not significantly different between them, the time required to achieve the required dilatation was significantly shorter for the normal saline infiltration group, 66.95 sec. ± 10.85 than for the misoprostol group which was 87.9 sec. ± 13.11. There was more difficulty in dilatation with more complications in the misoprostol group than in the normal saline infiltration group. CONCLUSIONS: Normal saline infiltration is a simple, readily available at the time of surgery and with fewer complications and shorter time of dilatation in comparison to vaginal misoprostol for a comparable efficacy.

Emergency cerclage in singleton pregnancies with painless cervical dilatation: A meta-analysis.

INTRODUCTION: Emergency cerclage is the most common active intervention in pregnant women with cervical insufficiency. This meta-analysis aimed to compare the effectiveness of emergency cerclage vs expectant management on maternal and perinatal outcomes, and to assess the current status of evidence. MATERIAL AND METHODS: A search was conducted from 1 June 2019 until 1 September 2019 and eligible studies were identified in the MEDLINE, Scopus, Cochrane and US clinical trials registry without limitations concerning the publication dates and languages. Randomized controlled trials (RCTs), non-RCTs and observational studies comparing emergency cerclage with no cerclage/expectant management, in women presenting with painless cervical dilatation were included. RESULTS: The electronic search yielded 3607 potential studies, of which 38 were fully reviewed and 12 observational studies (1021 participants) were included. Cerclage was superior to expectant management for the primary outcomes of preterm birth before 28 and 32 gestational weeks, OR 0.25 (95% CI 0.16-0.39, five studies, N = 392, I2 = 41%, low quality) and 0.08 (95% CI 0.02-0.29, four studies, N = 176, I2 = 51%, low quality), respectively. Cerclage was also superior to expectant management for the secondary outcomes of fetal loss OR 0.26 (95% CI 0.12-0.56, 8 studies, N = 455, I2 = 46%, very low-quality), pregnancy prolongation in days mean difference 47.45 (95% CI 39.89-55.0, 12 studies, N = 1027 I2 = 86%, very low quality), gestational age at birth in weeks mean difference 5.68 (95% CI 4.69-6.67, 9 studies, N = 892, I2 = 73%, very low quality), admission to neonatal intensive care OR 0.21 (95% CI 0.07-0.70, two studies, N = 79, I2 = 36%, very low quality) and neonatal death OR 0.12 (95% CI 0.04-0.34, five studies, N = 130, I2 = 0%, very low quality). There were no differences between cerclage and expectant management concerning premature rupture of membranes during or after the procedure OR 0.68 (95% CI 0.31-1.48, two studies, N = 155, I2 = 85%, very low quality) and chorioamnionitis OR 1.14 (95% CI 0.31-4.25, three studies, N = 88, I2 = 33%, very low quality). CONCLUSIONS: Emergency cerclage in pregnant women with painless cervical dilatation seems to decrease preterm births, prolong the pregnancy, and decrease the neonatal deaths and fetal losses, but does not increase the risk of chorioamnionitis and premature rupture of membranes. Despite the extremely favorable estimates for cerclage, the results should be viewed with caution because, as a result of the lack of randomized control trials, the quality of evidence is low to very low.

Feasibility, Reliability, and Agreement of Transperineal Ultrasound Measurement: Results from a Longitudinal Cohort Study.

OBJECTIVES: To evaluate the feasibility, reliability, and agreement of serial transperineal ultrasound (TPU) assessment of fetal head station (parasagittal angle of progression [psAOP], head-perineum distance [HPD], and head-symphysis distance [HSD]) and sonographic cervical dilatation (SCD), compared to fetal head station and cervical dilatation determined by vaginal examination, respectively. METHODS: This was a prospective longitudinal study in singleton pregnancies undergoing induction of labor at term. Paired assessment of fetal head station and cervical dilatation by vaginal examination, with TPU assessment of psAOP, HPD, HSD, and SCD was made serially. Feasibility, correlation, reliability, and agreement were determined. RESULTS: 1,139 paired measurements among 326 women were included. psAOP and HPD were achievable in all assessments. HSD was not achievable in 3.4% (11/326) due to high fetal head station. Fetal head station by vaginal examination was positively correlated with psAOP (rho = 0.70) but negatively correlated with HPD (rho = -0.57) and HSD (rho = -0.52). The feasibility to measure SCD reduced as cervical dilatation increased. Cervical dilatation and SCD were positively correlated (rho = 0.96) with strong agreement (concordant correlation coefficient = 0.925). CONCLUSIONS: Measurements of psAOP and HPD are feasible and correlate significantly with fetal head station by vaginal examination. Measurement of HSD is not feasible when fetal head station is high. Measurement of SCD is feasible, but it is more difficult in the advanced stage of labor. The correlation, reliability, and agreement between SCD and cervical dilatation by vaginal examination are high.

Associations among cervical dilatation at admission, intrapartum care, and birth mode in low-risk, nulliparous women.

BACKGROUND: Admission in early labor is associated with increased likelihood of cesarean birth, but the context in which this occurs is unclear. Previous research has explored the relationship between dilatation at admission and the use of single intrapartum interventions; however, the majority of women in the United States receive multiple intrapartum interventions. The objective of this study was to examine the associations among cervical dilatation at admission, intrapartum care, and birth mode in low-risk, nulliparous women with spontaneous onset of labor. METHODS: This was a cross-sectional, observational study of 21 858 nulliparous, singleton, term vertex births that occurred from 2002 to 2007 across nine hospitals in the Consortium on Safe Labor. Outcome measures included the individual and combined use of intrapartum interventions (amniotomy, epidural anesthesia, oxytocin augmentation) and birth mode. RESULTS: In this sample, 92.0% of women received at least one intrapartum intervention and 22.7% received all three interventions. After propensity score adjustment, women were more than twice as likely to receive the combination of amniotomy-epidural-oxytocin when admitted at 0-3 cm (RR 2.83 [95% CI 2.45-3.27]) and 4-5 cm (2.49 [2.15-2.89]) compared to 6-10 cm. Adjusted likelihood of cesarean birth was five times greater for women admitted at 0-3 cm (5.26 [4.36-6.34]) and two times greater for women admitted at 4-5 cm (2.27 [1.86-2.77]) compared to 6-10 cm. CONCLUSIONS: To promote normal physiologic birth, low-risk, nulliparous women should be engaged in shared decision-making about timing of admission after spontaneous onset of labor.

Pre-Induction Transperineal Ultrasound Assessment for the Prediction of Labor Outcome.

OBJECTIVE: To examine (1) the concordance of manual and automated para-symphyseal angle of progression (psAOP) measurements, (2) the repeatability of psAOP, head-symphysis distance, head-perineum distance, and sonographic cervical dilatation, and (3) the value of transperineal ultrasound (TPU) in predicting induction of labor (IOL) outcome. METHODS: We performed a prospective study in 308 women with singleton pregnancies undergoing IOL at term. Logistic regression analysis was used to determine which maternal factors, Bishop score, method of IOL, and TPU parameters were significant predictors of cesarean section (CS) and CS due to no progress (CS-NP). RESULTS: There was vaginal delivery in 225 (83.0%) and CS in 46 (17.0%) cases. The intra-class correlation coefficient between manual and automated psAOP was 0.866, but automated psAOP was 4.6° wider than manual measurement. All TPU parameters had an inter-observer intra-class correlation coefficient > 0.800. Significant independent prediction of CS and CS-NP was provided by maternal factors, previous vaginal delivery, and psAOP. There was no improvement in area under the receiver-operating characteristic curve with the addition of psAOP to maternal factors. CONCLUSIONS: All TPU parameters are reproducible. Comparing the three TPU parameters for fetal head station, only psAOP is a significant independent predictor of CS; however, it is unlikely to be useful in predicting IOL outcome.

Cervical dilatation patterns of 'low-risk' women with spontaneous labour and normal perinatal outcomes: a systematic review.

BACKGROUND: The call for women-centred approaches to reduce labour interventions, particularly primary caesarean section, has renewed an interest in gaining a better understanding of natural labour progression. OBJECTIVE: To synthesise available data on the cervical dilatation patterns during spontaneous labour of 'low-risk' women with normal perinatal outcomes. SEARCH STRATEGY: PubMed, EMBASE, CINAHL, POPLINE, Global Health Library, and reference lists of eligible studies. SELECTION CRITERIA: Observational studies and other study designs. DATA COLLECTION AND ANALYSIS: Two authors extracted data on: maternal characteristics; labour interventions; the duration of labour centimetre by centimetre; and the duration of labour from dilatation at admission through to 10 cm. We pooled data across studies using weighted medians and employed the Bootstrap-t method to generate the corresponding confidence bounds. MAIN RESULTS: Seven observational studies describing labour patterns for 99 971 women met our inclusion criteria. The median time to advance by 1 cm in nulliparous women was longer than 1 hour until a dilatation of 5 cm was reached, with markedly rapid progress after 6 cm. Similar labour progression patterns were observed in parous women. The 95th percentiles for both parity groups suggest that it was not uncommon for some women to reach 10 cm, despite dilatation rates that were much slower than the 1-cm/hour threshold for most part of their first stage of labours. CONCLUSION: An expectation of a minimum cervical dilatation threshold of 1 cm/hour throughout the first stage of labour is unrealistic for most healthy nulliparous and parous women. Our findings call into question the universal application of clinical standards that are conceptually based on an expectation of linear labour progress in all women. FUNDING: UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research, World Health Organization, and the United States Agency for International Development (USAID). TWEETABLE ABSTRACT: Cervical dilatation threshold of 1 cm/hour throughout labour is unrealistic for most women, regardless of parity.

Cervical Dilatation Curves of Spontaneous Deliveries in Pregnant Japanese Females.

Background: Although cervical dilatation curves are crucial for appropriate management of labor progression, abnormal labor progression and obstetric interventions were included in previous and widely-used cervical dilatation curves. We aimed to describe the cervical dilatation curves of normal labor progression in pregnant Japanese females without abnormal labor progression and obstetric interventions. Methods: We completed retrospective obstetric record reviews on 3172 pregnant Japanese females (parity = 0, n = 1047; parity = 1, n = 1083; parity ≥ 2, n = 1042), aged 20 to 39 years old at delivery, with pregravid body mass indices of less than 30. All patients underwent spontaneous deliveries with term, singleton, cephalic and live newborns of appropriate-for-gestational age birthweight, without adverse neonatal outcomes. We characterized labor progression patterns by examining the relationship between elapsed times from the full dilatation and cervical dilatation stages, and labor durations by examining the distribution of time intervals from one cervical dilatation stage, to the next, and ultimately to the full dilatation. Results: Fastest cervical changes occurred at 6 cm (primiparas) and 5 cm (multiparas) of dilatation. The 95%tile of labor progression took over 3 hours to progress from 6 cm to 7 cm (primiparas), and over 2 hours to progress from 5 cm to 6 cm (multiparas). The 5%tile of traverse time to the full dilatation, during the active phase, was less than 1 hour (primiparas) and 0.5 hours (multiparas). At the end of the active phase, no deceleration phase was observed. Conclusions: Active labor may not start until 5 cm of dilatation. At the beginning of the active phase, cervical dilatation was slower than previously described. These results may reduce opportunities for obstetric interventions during labor progression.

Optimal Dose of Vaginal Misoprostol for Cervical Ripening before Hysteroscopy: A Randomized Double-Blind Study.

STUDY OBJECTIVE: To evaluate the optimal dose of vaginal misoprostol (200 and 400 µg) for cervical priming before operative hysteroscopy. DESIGN: A randomized, controlled, double-blind trial (Canadian Task Force classification I). SETTING: A university hospital. PATIENTS: Sixty-eight patients undergoing operative hysteroscopy. INTERVENTIONS: Patients were randomized to receive a low (200 µg) or high (400 µg) dose of misoprostol administered vaginally 8 hours before operative hysteroscopy. MEASUREMENTS AND MAIN RESULTS: The primary outcome was perioperative dilatation time, and the secondary outcome measurements included the subjective difficulty of cervical dilatation assessed by the surgeon, operative time, self-reported adverse events after vaginal administration and before the start of the operation, and complications during the procedure. A comparison of the 200-µg (n = 34) and 400-µg (n = 34) misoprostol cohorts revealed similarities when comparing time with cervical dilatation, operative difficulty, result, and time. Misoprostol-related adverse events were significantly lower in the 200-µg cohort than the 400-µg cohort (58.8% vs 85.3%, p = .015). Abdominal pain was the most common adverse event and was higher in the 400-µg cohort compared with the 200-µg cohort (73.5% vs 50.0%, p = .046). However, there were no operative delays resulting from adverse events, and all individuals reported the procedure to be tolerable and recovered without medication or treatment. CONCLUSION: Both 200 µg and 400 µg vaginally administered misoprostol are effective for cervical dilatation, and we recommend vaginal administration of 200 µg misoprostol for cervical dilatation 8 hours before operative hysteroscopy because of lower adverse events in the 200-µg group as well as similar efficacy between cohorts.