Duration of the active first stage of labour and severe perineal lacerations and maternal postpartum complications: a population-based cohort study

OBJECTIVE

The impact of first stage labour duration on maternal outcomes is sparsely investigated. We aimed to study the association between a longer active first stage and maternal complications in the early postpartum period.

DESIGN

A population-based cohort study.

SETTING

Regions of Stockholm and Gotland, Sweden, 2008-2020.

POPULATION

A cohort of 159 459 term, singleton, vertex pregnancies, stratified by parity groups.

METHODS

The exposure was active first stage duration, categorised in percentiles. Poisson regression analysis was performed to estimate the adjusted relative risk (aRR) and the 95% confidence interval (95% CI). To investigate the effect of second stage duration on the outcome, mediation analysis was performed.

MAIN OUTCOME MEASURES

Severe perineal lacerations (third or fourth degree), postpartum infection, urinary retention and haematoma in the birth canal or ruptured sutures.

RESULTS

The risks of severe perineal laceration, postpartum infection and urinary retention increased with a longer active first stage, both overall and stratified by parity group. The aRR increased with a longer active first stage, using duration of <50th percentile as the reference. In the ≥90th percentile category, the aRR for postpartum infection was 1.64 (95% CI 1.46-1.84) in primiparous women, 2.43 (95% CI 1.98-2.98) in parous women with no previous caesarean delivery (CD) and 2.33 (95% CI 1.65-3.28) in parous women with a previous CD. The proportion mediated by second stage duration was 33.4% to 36.9% for the different outcomes in primiparous women. The risk of haematoma or ruptured sutures did not increased with a longer active first stage.

CONCLUSIONS

Increasing active first stage duration is associated with maternal complications in the early postpartum period.

Operative delivery in the second stage of labor and preterm birth in a subsequent pregnancy: a systematic review and meta-analysis

OBJECTIVE

This study aimed to quantify the association between mode of operative delivery in the second stage of labor (cesarean delivery vs operative vaginal delivery) and spontaneous preterm birth in a subsequent pregnancy.

DATA SOURCES

MEDLINE, Embase, EmCare, CINAHL, the Cochrane Library, Web of Science: Core Collection, and Scopus were searched from database inception to April 1, 2023.

STUDY ELIGIBILITY CRITERIA

All retrospective cohort studies with participants who had a second-stage cesarean delivery (defined as intrapartum cesarean delivery at full cervical dilation) or operative vaginal delivery (including forceps- and/or vacuum-assisted delivery) and that reported the rate of preterm birth (either spontaneous or not specified) in subsequent pregnancy were included.

METHODS

Both a descriptive analysis and a meta-analysis were performed. A meta-analysis was performed for dichotomous data using the Mantel-Haenszel random-effects model and used the odds ratio as an effect measure with 95% confidence intervals. The risk of bias was assessed using Cochrane's 2022 Risk Of Bias In Non-randomized Studies of Exposure tool.

RESULTS

After screening 2671 articles from 7 databases, a total of 18 retrospective cohort studies encompassing 605,138 patients were included. The pooled rates of spontaneous preterm birth in a subsequent pregnancy were 6.9% (12 studies) after second-stage cesarean delivery and 2.6% (8 studies) after operative vaginal delivery. A total of 7 studies encompassing 75,460 patients compared the primary outcome of spontaneous preterm birth after second-stage cesarean delivery vs operative vaginal delivery in an index pregnancy with an odds ratio of 2.01 (95% confidence interval, 1.57-2.58) in favor of operative vaginal delivery. However, most studies did not include important confounding factors, did not address exposure misclassification because of failed operative vaginal delivery, and considered operative vaginal delivery as a homogeneous category with no distinction between forceps- and vacuum-assisted deliveries.

CONCLUSION

Although a synthesis of the existing literature suggests that the risk of spontaneous preterm birth is higher in those with a previous second-stage cesarean delivery than in those with operative vaginal delivery, the risk of bias in these studies is very high. Findings should be interpreted with caution.

Optimizing the length of the second stage and management of pushing

Although the optimal length of the second stage of labor to minimize maternal and neonatal morbidities and optimize spontaneous vaginal delivery is not known, available evidence suggests that increasing length of the second stage is associated with increasing maternal and neonatal morbidity. Thus, evidence-based strategies to safely shorten the second stage, such as initiating pushing when complete dilation is reached among those with neuraxial anesthesia, is prudent. Many aspects of optimal management of the second stage of labor require future study to continue to guide clinical second-stage management.

The physiology and pharmacology of oxytocin in labor and in the peripartum period

Oxytocin is a reproductive hormone implicated in the process of parturition and widely used during labor. Oxytocin is produced within the supraoptic nucleus and paraventricular nucleus of the hypothalamus and released from the posterior pituitary lobe into the circulation. Oxytocin is released in pulses with increasing frequency and amplitude in the first and second stages of labor, with a few pulses released in the third stage of labor. During labor, the fetus exerts pressure on the cervix of the uterus, which activates a feedforward reflex-the Ferguson reflex-which releases oxytocin. When myometrial contractions activate sympathetic nerves, it decreases oxytocin release. When oxytocin binds to specific myometrial oxytocin receptors, it induces myometrial contractions. High levels of circulating estrogen at term make the receptors more sensitive. In addition, oxytocin stimulates prostaglandin synthesis and release in the decidua and chorioamniotic membranes by activating a specific type of oxytocin receptor. Prostaglandins contribute to cervical ripening and uterine contractility in labor. The oxytocin system in the brain has been implicated in decreasing maternal levels of fear, pain, and stress, and oxytocin release and function during labor are stimulated by a social support. Moreover, studies suggest, but have not yet proven, that labor may be associated with long-term, behavioral and physiological adaptations in the mother and infant, possibly involving epigenetic modulation of oxytocin production and release and the oxytocin receptor. In addition, infusions of synthetic oxytocin are used to induce and augment labor. Oxytocin may be administered according to different dose regimens at increasing rates from 1 to 3 mIU/min to a maximal rate of 36 mIU/min at 15- to 40-minute intervals. The total amount of synthetic oxytocin given during labor can be 5 to 10 IU, but lower and higher amounts of oxytocin may also be given. High-dose infusions of oxytocin may shorten the duration of labor by up to 2 hours compared with no infusion of oxytocin; however, it does not lower the frequency of cesarean delivery. When synthetic oxytocin is administered, the plasma concentration of oxytocin increases in a dose-dependent way: at infusion rates of 20 to 30 mIU/min, plasma oxytocin concentration increases approximately 2- to 3-fold above the basal level. Synthetic oxytocin administered at recommended dose levels is not likely to cross the placenta or maternal blood-brain barrier. Synthetic oxytocin should be administered with caution as high levels may induce tachystole and uterine overstimulation, with potentially negative consequences for the fetus and possibly the mother. Of note, 5 to 10 IU of synthetic oxytocin is often routinely given as an intravenous or intramuscular bolus administration after delivery to induce uterine contractility, which, in turn, induces uterine separation of the placenta and prevents postpartum hemorrhage. Furthermore, it promotes the expulsion of the placenta.

Soft-tissue dystocia due to paradoxical contraction of the levator ani as a cause of prolonged second stage: concept, diagnosis, and potential treatment

Smaller pelvic floor dimensions seem to have been an evolutionary need to provide adequate support for the pelvic organs and the fetal head. Pelvic floor dimension and shape contributed to the complexity of human birth. Maternal pushing associated with pelvic floor muscle relaxation is key to vaginal birth. Using transperineal ultrasound, pelvic floor dimensions can be objectively measured in both static and dynamic conditions, such as pelvic floor muscle contraction and pushing. Several studies have evaluated the role of the pelvic floor in labor outcomes. Smaller levator hiatal dimensions seem to be associated with a longer duration of the second stage of labor and a higher risk of cesarean and operative deliveries. Furthermore, smaller levator hiatal dimensions are associated with a higher fetal head station at term of pregnancy, as assessed by transperineal ultrasound. With maternal pushing, most women can relax their pelvic floor, thus increasing their pelvic floor dimensions. Some women contract rather than relax their pelvic floor muscles under pushing, which is associated with a reduction in the anteroposterior diameter of the levator hiatus. This phenomenon is called levator ani muscle coactivation. Coactivation in nulliparous women at term of pregnancy before the onset of labor is associated with a higher fetal head station at term of pregnancy and a longer duration of the second stage of labor. In addition, levator ani muscle coactivation in nulliparous women undergoing induction of labor is associated with a longer duration of the active second stage of labor. Whether we can improve maternal pelvic floor relaxation with consequent improvement in labor outcomes remains a matter of debate. Maternal education, physiotherapy, and visual feedback are promising interventions. In particular, ultrasound visual feedback before the onset of labor can help women increase their levator hiatal dimensions and correct levator ani muscle coactivation in some cases. Ultrasound visual feedback in the second stage of labor was found to help women push more efficiently, thus obtaining a lower fetal head station at ultrasound and a shorter duration of the second stage of labor. The available evidence on the role of any intervention aimed to aid women to better relax their pelvic floor remains limited, and more studies are needed before considering its routine clinical application.

Ultrasonographic Evaluation of the Second Stage of Labor according to the Mode of Delivery: A Prospective Study in Greece

BACKGROUND AND OBJECTIVES

Accurate diagnosis of labor progress is crucial for making well-informed decisions regarding timely and appropriate interventions to optimize outcomes for both the mother and the fetus. The aim of this study was to assess the progress of the second stage of labor using intrapartum ultrasound.

MATERIAL AND METHODS

This was a prospective study (December 2022-December 2023) conducted at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece. Maternal-fetal and labor characteristics were recorded, and two ultrasound parameters were measured: the angle of progression (AoP) and the head-perineum distance (HPD). The correlation between the two ultrasonographic values and the maternal-fetal characteristics was investigated. Multinomial regression analysis was also conducted to investigate any potential predictors of the mode of delivery.

RESULTS

A total of 82 women at the second stage of labor were clinically and sonographically assessed. The mean duration of the second stage of labor differed between vaginal and cesarean deliveries (65.3 vs. 160 min; p-value < 0.001) and between cesarean and operative vaginal deliveries (160 vs. 88.6 min; p-value = 0.015). The occiput anterior position was associated with an increased likelihood of vaginal delivery (OR: 24.167; 95% CI: 3.8-152.5; p-value < 0.001). No significant differences were identified in the AoP among the three different modes of delivery (vaginal: 145.7° vs. operative vaginal: 139.9° vs. cesarean: 132.1°; p-value = 0.289). The mean HPD differed significantly between vaginal and cesarean deliveries (28.6 vs. 41.4 mm; p-value < 0.001) and between cesarean and operative vaginal deliveries (41.4 vs. 26.9 mm; p-value = 0.002); it was correlated significantly with maternal BMI (r = 0.268; p-value = 0.024) and the duration of the second stage of labor (r = 0.256; p-value = 0.031). Low parity (OR: 12.024; 95% CI: 6.320-22.876; p-value < 0.001) and high HPD (OR: 1.23; 95% CI: 1.05-1.43; p-value = 0.007) were found to be significant predictors of cesarean delivery.

CONCLUSIONS

The use of intrapartum ultrasound as an adjunctive technique to the standard clinical evaluation may enhance the diagnostic approach to an abnormal labor progress and predict the need for operative vaginal or cesarean delivery.

The use of bubble charts in analyzing the global second-stage cesarean delivery rates: a systematic review

OBJECTIVE

This study aimed to systematically review the worldwide second-stage cesarean delivery rate concerning pre-second-stage cesarean delivery and assisted vaginal birth rates.

DATA SOURCES

PubMed, Medline Ovid, EBSCOhost, Embase, Scopus, and Google Scholar were queried from inception to February 2023, with the following terms: "full dilatation," "second stage," and "cesarean," with their word variations. Furthermore, an additional cohort of 353,434 cases from our recently published study was included.

STUDY ELIGIBILITY CRITERIA

Only original studies that provided sufficient information on the number of pre-second-stage cesarean deliveries, second-stage cesarean deliveries, and vaginal births were included for the calculation of different modes of delivery. Systemic reviews, meta-analyses, or case reports were excluded.

METHODS

Study identification and data extraction were independently performed by 2 authors. Selected studies were categorized on the basis of parity, study period, and geographic regions for comparison.

RESULTS

A total of 25 studies were included. The overall pre-second-stage cesarean delivery rate, the second-stage cesarean delivery rate, and the second-stage cesarean delivery-to-assisted vaginal birth ratio were 17.94%, 2.65%, and 0.19, respectively. Only 5 studies described singleton, term, cephalic presenting pregnancies of nulliparous women, and their second-stage cesarean delivery rates were significantly higher than those studies with cohorts of all parity groups (4.50% vs 0.83%; P<.05). In addition, the second-stage cesarean delivery rate showed a secular increase across 2009 (0.70% vs 1.05%; P<.05). Moreover, it was the highest among African studies (5.14%) but the lowest among studies from East Asia and South Asia (0.94%). The distributions of second-stage cesarean delivery rates of individual studies and subgroups were shown with that of pre-second-stage cesarean delivery and assisted vaginal birth using the bubble chart.

CONCLUSION

The overall worldwide pre-second-stage cesarean delivery rate was 17.94%, the second-stage cesarean delivery rate was 2.65%, and the second-stage cesarean delivery-to-assisted vaginal birth ratio was 0.19. The African studies had the highest second-stage cesarean delivery rate (5.14%) and second-stage cesarean delivery-to-assisted vaginal birth ratio (1.88), whereas the studies from East Asia and South Asia were opposite (0.94% and 0.11, respectively).

Impacted fetal head extraction methods at second stage cesarean and subsequent preterm delivery: A multicenter study

OBJECTIVE

Second-stage cesarean delivery (CD) is associated with subsequent preterm birth (PTB). It has been suggested that an increased risk of PTB after second-stage cesarean delivery could be linked to a higher chance of cervical injury due to the extension of the uterine incision. Previous studies have shown that reverse breech extraction is associated with lower rates of uterine incision extensions compared to the "push" method. We aimed to investigate the association between the method of fetal extraction during second-stage CD and the rate of spontaneous PTB (sPTB), as well as other maternal and neonatal outcomes during the subsequent pregnancy.

METHODS

This was a multicenter retrospective cohort study. The study population included women in their first subsequent singleton delivery following a second-stage CD between 2004 and 2021. The main exposure of interest was the method of fetal extraction in the index CD ("push" method vs. reverse breech extraction). The primary outcome of this study was sPTB <37 weeks in the subsequent pregnancy. Secondary outcomes were overall PTB, trial of labor, and other adverse maternal and neonatal outcomes. Univariate analysis was followed by multiple logistic regression modeling.

RESULTS

During the study period, 2969 index CD during second stage were performed, of those 583 met the inclusion criteria, of whom 234 (40.1%) had fetal extraction using the reverse breech extraction method, while 349 (59.9%) had the "push" method for extraction. In univariate analysis, women in those two groups had statistically similar rates of sPTB (3.7% vs. 3.0%; odds ratio [OR] 1.25, 95% CI: 0.49-3.19) and overall PTB (<37, <34 and <32 weeks), as well as other maternal, neonatal, and trial of labor outcomes. This was confirmed by multivariate analyses with an adjusted OR of 1.27 (95% CI: 0.43-3.71) for sPTB.

CONCLUSION

Among women with a previous second-stage CD, no significant difference was observed in PTB rates in the subsequent pregnancies following the "push" method compared to the reverse breech extraction method.

Moderate or intensive management of the active phase of second-stage labor and risk of urinary and anal incontinence: results of the PASST randomized controlled trial

BACKGROUND

Incontinence occurs frequently in the postpartum period. Several theoretical pathophysiological models may underlie the hypothesis that different types of management of the active phase of the second stage of labor have different effects on pelvic floor muscles and thus perhaps affect urinary and anal continence.

OBJECTIVE

This study aimed to evaluate the impact of "moderate pushing" on the occurrence of urinary or anal incontinence compared with "intensive pushing," and to determine the factors associated with incontinence at 6 months postpartum.

STUDY DESIGN

This was a planned analysis of secondary objectives of the PASST (Phase Active du Second STade) trial, a multicenter randomized controlled trial. PASST included nulliparous women with singleton term pregnancies and epidural analgesia, who were randomly assigned at 8 cm of dilatation to either the intervention group that used "moderate" pushing (pushing only twice during each contraction, resting regularly for 1 contraction in 5 without pushing, and no time limit on pushing) or the control group following the usual management of "intensive" pushing (pushing 3 times during each contraction, with no contractions without pushing, with an obstetrician called to discuss operative delivery after 30 minutes of pushing). Data about continence were collected with validated self-assessment questionnaires at 6 months postpartum. Urinary incontinence was defined by an ICIQ-UI SF (International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form) score ≥1 and anal incontinence by a Wexner score ≥2. A separate analysis was also performed among the more severely affected women (ICIQ-UI SF ≥6 and Wexner ≥5). Factors associated with incontinence were assessed with univariate and multivariable analyses.

RESULTS

Among 1618 women initially randomized, 890 (55%) returned the complete questionnaire at 6 months. The rate of urinary incontinence was 36.6% in the "moderate" pushing group vs 38.5% in the "intensive" pushing group (relative risk, 0.95; 95% confidence interval, 0.80-1.13), whereas the rate of anal incontinence was 32.2% vs 34.6% (relative risk, 0.93; 95% confidence interval, 0.77-1.12). None of the obstetrical factors studied related to the second stage of labor influenced the occurrence of urinary or anal incontinence, except operative vaginal delivery, which increased the risk of anal incontinence (adjusted odds ratio, 1.50; 95% confidence interval, 1.04-2.15).

CONCLUSION

The results of the PASST trial indicate that neither moderate nor intensive pushing efforts affect the risk of urinary or anal incontinence at 6 months postpartum among women who gave birth under epidural analgesia.

Improving Nurse Management of the Second Stage of Labor

OBJECTIVE

To develop, implement, and evaluate an educational program to improve nurses' management of the second stage of labor.

DESIGN

Evidence-based practice project guided by the Iowa Model-Revised.

SETTING

Acute care teaching hospital in central California averaging 2,100 births/year with 12 labor, delivery, and recovery rooms and a Level III nursery.

PARTICIPANTS

Eighteen registered nurses participated in the educational intervention.

INTERVENTION

An instructional course addressed contemporary labor management guidelines and delayed and open/closed glottis pushing. Assessment/documentation of maternal-fetal status, progress/fetal descent, and nurse/provider communication were discussed. Participants engaged in an interactive experience regarding maternal positions.

MEASUREMENTS

Data collected from the electronic health record included the number of position changes, nurse/provider communication interactions, and minutes from 10 cm to birth and minutes in delayed pushing.

RESULTS

Second-stage labor outcomes for nulliparous patients at term with a singleton in vertex presentation improved with more position changes and percentage of spontaneous vaginal births. Patients of nurses who participated in the educational intervention (n = 18) had a vaginal birth rate of 87.5% and a surgical birth rate of 6.2%. Patients of nurses who did not participate in the educational intervention (n = 31) had a vaginal birth rate of 81.8% and a surgical birth rate of 9.1%.

CONCLUSION

Based on the positive response to the intervention and improved clinical outcomes, regularly scheduled interactive nursing education focused on strategies to improve the second stage of labor may be beneficial.

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.

Does a three-hour delayed pushing benefit the mode of delivery?

OBJECTIVE

The objective of this study was to compare two strategies for passive second stage management: three-hour vs two-hour delayed pushing after the diagnosis of full cervical dilation on mode of delivery and perinatal outcomes.

STUDY DESIGN

This retrospective observational study included low-risk nulliparous women who reatched full cervical dilation under epidural analgesia with a single term fetus in cephalic presentation and normal fetal heart rate, between September and December 2016. Mode of delivery (spontaneous vaginal delivery versus operative delivery including cesarean section and instrumental vaginal delivery) and perinatal outcomes (post-partum hemorrhage, perineal lacerations, 5-min Apgar score, umbilical cord pH and transfer to neonatal intensive care unit) were compared between two maternity units: maternity unit A, where women could have up to a three-hour delayed pushing period after full cervical dilation diagnosis, and maternity unit B, where the delayed pushing period was a maximum of 2 hours. Outcomes were compared using univariate and multivariable analyses. Adjusted odds ratios (aOR) were estimated using a logistic regression multivariable model that included potential cofounders.

RESULTS

During the study period, 614 women were included, 305 in maternity unit A and 309 in maternity unit B. Women's pre-existing characteristics were comparable between the two maternity units. Women delivering in the maternity unit A had significantly lower risks of having an operative delivery compared to women delivering in the maternity unit B (respectively 18.4 vs 26.9%; aOR = 0.64; 95%CI [0.43 - 0.96]). Perinatal outcomes were comparable in the two maternity units, particularly in terms of post-partum hemorrhage rates (7.4 vs 7.8%; aOR = 1,19 [0.65 - 2.19]).

CONCLUSION

Increasing the possible length of the delayed pushing period from 2 to 3 hours after the diagnosis of full cervical dilation in low-risk nulliparous women appears to reduce operative deliveries without adverse effects on maternal or neonatal morbidity.

Late preterm delivery has a distinctive second-stage duration and characteristics

BACKGROUND

Late preterm neonates born between 34.0 and 36.6 weeks' gestation are at increased risk for short- and long-term morbidity and mortality when compared with their term counterparts. Currently, no separate labor curve is available for late preterm births, and this group's optimal duration of the second stage of labor has never been defined separately.

OBJECTIVE

This study aimed to compare the second stage duration between late preterm and term births.

STUDY DESIGN

This was a retrospective study from May 2014 until May 2021. Eligible were women with a singleton pregnancy, vertex presentation, spontaneous or induced onset of labor, and those who delivered vaginally beyond 34.0 weeks of gestation. The primary outcome of our study was to compare and characterize the second stage of labor duration between late preterm and term births.

RESULTS

We analyzed 962 late preterm and 9476 term vaginal deliveries. Women who delivered during the late preterm period were more likely to be multiparous (52.4% vs 45.2%; P<.001) and fewer required oxytocin during labor (41.2% vs 54.4%; P<.001) or used epidural analgesia (75.2% vs 83.6%; P<.001). The overall mean duration of the second stage of labor was significantly shorter in the late preterm period than at term (1.08±1.09 hours vs 1.49±1.22 hours; P<.001). This was even more pronounced for nulliparous women (1.05±1.00 hours vs 2.10±1.17 hours; P<.001). Among multiparous women, epidural use significantly affected the duration of the second stage of labor, and the second stage was relatively longer during the late preterm period than at term in this subgroup (1.16 vs 0.5 hours; P<.001). Using a multivariate Cox regression, variables such as maternal age (hazard ratio, 1.02; 95% confidence interval, 1.01-1.04), parity (hazard ratio, 4.11; 95% confidence interval, 3.65-4.63), preterm birth (hazard ratio, 2.08; 95% confidence interval, 1.4-3.10), and birthweight at delivery (hazard ratio, 1.15; 95% confidence interval, 1.01-1.30) shortened the second stage, whereas induction of labor (hazard ratio, 0.75; 95% confidence interval, 0.66-0.86) and epidural use (hazard ratio, 0.68; 95% confidence interval, 0.64-0.86) extended its total duration. Regardless of parity, lower rates of operative vaginal deliveries were observed in the late preterm period than at term (3.7% vs 15.5%; P<.001). This period was also associated with lower rates of third- and fourth-degree perineal lacerations (0.2% vs 2.2%; P<.001) but higher rates of chorioamnionitis (1.7% vs 0.1%; P<.001), Apgar score at 5 minutes <7 (1.0% vs 0.2%; P<.001), and admission to the neonatal intensive care unit (19.3% vs 1.0%; P<.001).

CONCLUSION

Women who delivered vaginally during the late preterm period had a distinctive second-stage duration. Primarily, it was shown to be significantly shorter for nulliparous and multiparous women. Future studies should further clarify the optimal duration of this stage in relation to neonatal outcomes at such a vulnerable period.

Partogram of Grandmultiparous Parturients: A Multicenter Cohort Study

Sparse and conflicting data exist regarding the normal partogram of grand-multiparous (GMP, defined as parity of 6+) parturients. Customized partograms may potentially lower cesarean delivery rates for protraction disorders in this population. In this study, we aim to construct a normal labor curve of GMP women and compare it to the multiparous (MP, defined as parity of 2-5) partogram. We conducted a multicenter retrospective cohort analysis of deliveries between the years 2003 and 2019. Eligible parturients were the trials of labor of singletons ≥37 + 0 weeks in cephalic presentation with ≥2 documented cervical examinations during labor. Exclusion criteria were elective cesarean delivery without a trial of labor, preterm labor, major fetal anomalies, and fetal demise. GMP comprised the study group while the MP counterparts were the control group. A total of 78,292 deliveries met the inclusion criteria, comprising 10,532 GMP and 67,760 MP parturients. Our data revealed that during the first stage of labor, cervical dilation progressed at similar rates in MPs and GMPs, while head descent was a few minutes faster in GMPs compared to MPs, regardless of epidural anesthesia. The second stage of labor was faster in GMPs compared to MPs; the 95th percentile of the second stage duration of GMPs (48 min duration) was 43 min less than that of MPs (91 min duration). These findings remained similar among deliveries with and without epidural analgesia or labor induction. We conclude that GMPs' and MPs' cervical dilation progression in the active phase of labor was similar, and the second stage of labor was shorter in GMPs, regardless of epidural use. Thus, GMPs' uterus function during labor corresponds, and possibly surpasses, that of MPs. These findings indicate that health providers can use the standard partogram of the active phase of labor when caring for GMP parturients.

Put your weight behind it-Effect of body mass index on the active second stage of labour: A retrospective cohort study

OBJECTIVE

To explore the duration of the active phase of the second stage of labour in relation to maternal pre-pregnant body mass index (BMI).

DESIGN

Retrospective cohort study.

SETTING

Labour wards of three Norwegian university hospitals, 2012-2019.

POPULATION

Nulliparous and parous women without previous caesarean section with a live singleton fetus in cephalic presentation and spontaneous onset of labour, corresponding to the Ten Group Classification System (TGCS) group 1 and 3.

METHODS

Women were stratified to BMI groups according to WHO classification, and estimated median duration of the active phase of the second stage of labour was calculated using survival analyses. Caesarean sections and operative vaginal deliveries during the active phase were censored.

MAIN OUTCOME MEASURES

Estimated median duration of the active phase of second stage of labour.

RESULTS

In all, 47 942 women were included in the survival analyses. Increasing BMI was associated with shorter estimated median duration of the active second stage in both TGCS groups. In TGCS group 1, the estimated median durations (interquartile range) were 44 (26-75), 43 (25-71), 39 (22-70), 33 (18-63), 34 (19-54) and 29 (16-56) minutes in BMI groups 1-6, respectively. In TGCS group 3, the corresponding values were 11 (6-19), 10 (6-17), 10 (6-16), 9 (5-15), 8 (5-13) and 7 (4-11) minutes. Increasing BMI remained associated with shorter estimated median duration in analyses stratified by oxytocin augmentation and epidural analgesia.

CONCLUSION

Increasing BMI was associated with shorter estimated median duration of the active second stage of labour.

The Effect of Epidural Analgesia on Labour and Neonatal and Maternal Outcomes in 1, 2a, 3, and 4a Robson's Classes: A Propensity Score-Matched Analysis

Background: Lumbar epidural analgesia (EA) is the most commonly used method for reducing labour pain, but its impact on the duration of the second stage of labour and on neonatal and maternal outcomes remains a matter of debate. Our aim was to examine whether EA affected the course and the outcomes of labour among patients divided according to the Robson-10 group classification system. Methods: Patients of Robson’s classes 1, 2a, 3, and 4a were divided into either the EA group or the non-epidural analgesia (NEA) group. A propensity score-matching analysis was performed to balance the intergroup differences. The primary goal was to analyse the duration of the second stage of labour. The secondary goals were to evaluate neonatal and maternal outcomes. Results: In total, 21,808 cases were analysed. The second stage of labour for all groups was prolonged using EA (p < 0.05) without statistically significant differences in neonatal outcomes. EA resulted in a lower rate of episiotomies in nulliparous patients, with a higher rate of operative vaginal deliveries (OVD) (p < 0.05) and Caesarean sections (CS) (p < 0.05) in some classes. Conclusions: EA prolonged the duration of labour without affecting neonatal outcomes and reduced the rate of episiotomies, but also increased the rate of OVDs.

Alternative to intensive management of the active phase of the second stage of labor: a multicenter randomized trial (Phase Active du Second STade trial) among nulliparous women with an epidural

BACKGROUND

There is no consensus on an optimal strategy for managing the active phase of the second stage of labor. Intensive pushing could not only reduce pushing duration, but also increase abnormal fetal heart rate because of cord compression and reduced placental perfusion and oxygenation resulting from the combination of uterine contractions and maternal expulsive forces. Therefore, it may increase the risk of neonatal acidosis and the need for operative vaginal delivery.

OBJECTIVE

This study aimed to assess the effect of the management encouraging "moderate" pushing vs "intensive" pushing on neonatal morbidity.

STUDY DESIGN

This study was a multicenter randomized controlled trial, including nulliparas in the second stage of labor with an epidural and a singleton cephalic fetus at term and with a normal fetal heart rate. Of note, 2 groups were defined: (1) the moderate pushing group, in which women had no time limit on pushing, pushed only twice during each contraction, and observed regular periods without pushing, and (2) the intensive pushing group, in which women pushed 3 times during each contraction and the midwife called an obstetrician after 30 minutes of pushing to discuss operative delivery (standard care). The primary outcome was a composite neonatal morbidity criterion, including umbilical arterial pH of <7.15, base excess of >10 mmol/L, lactate levels of >6 mmol/L, 5-minute Apgar score of <7, and severe neonatal trauma. The secondary outcomes were mode of delivery, episiotomy, obstetrical anal sphincter injuries, postpartum hemorrhage, and maternal satisfaction.

RESULTS

The study included 1710 nulliparous women. The neonatal morbidity rate was 18.9% in the moderate pushing group and 20.6% in the intensive pushing group (P=.38). Pushing duration was longer in the moderate group than in the intensive group (38.8±26.4 vs 28.6±17.0 minutes; P<.001), and its rate of operative delivery was 21.1% in the moderate group compared with 24.8% in the intensive group (P=.08). The episiotomy rate was significantly lower in the moderate pushing group than in the intensive pushing group (13.5% vs 17.8%; P=.02). We found no significant difference for obstetrical anal sphincter injuries, postpartum hemorrhage, or maternal satisfaction.

CONCLUSION

Moderate pushing has no effect on neonatal morbidity, but it may nonetheless have benefits, as it was associated with a lower episiotomy rate.

Prolonged passive second stage of labor in nulliparous women-Prevalence and risk factors: A historical cohort study

INTRODUCTION

This study examined the prevalence of and risk factors for a prolonged passive second stage of labor in nulliparous women.

MATERIAL AND METHODS

This was a historical cohort study of all nulliparous women (n = 1131) at two delivery units in Sweden. Maternal and obstetric data were obtained from electronic medical records during 2019. Duration of the passive second stage was measured as time from retracted cervix to start of pushing. Prolonged passive second stage was defined as ≥2 h. Prevalence was calculated and associations between prolonged passive second stage and maternal, obstetric and neonatal characteristics and potential risk factors were assessed using logistic regression models.

RESULTS

The prevalence of prolonged passive second stage was 37.6%. Factors associated with an increased risk of prolonged passive second stage were epidural analgesia (adjusted odds ratio [aOR] 3.93; 95% confidence interval [CI] 2.90-5.34), malpresentation (aOR 2.26; 95% CI 1.27-4.05), maternal age ≥ 30 years (aOR 2.00; 95% CI 1.50-2.65) and birthweight ≥ 4 kg (aOR 1.50; 95% CI 1.05-2.15). Maternal body mass index ≥30 (aOR 0.52; 95% CI 0.34-0.79) and noncohabiting (aOR 0.51; 95% CI 0.30-0.89) reduced the odds of prolonged passive second stage.

CONCLUSIONS

A prolonged passive second stage of labor in nulliparous women is common (n = 425 [38%]). We found epidural analgesia, malpresentation, maternal age ≥ 30 years and birthweight ≥4 kg to be major risk factors associated with an increased risk of a prolonged passive second stage. Birth outcomes for prolonged passive second stage need to be investigated to strengthen evidence for the management of the second stage of labor.

Intrapartum ultrasound measurement of angle of progression at the onset of the second stage of labor for prediction of spontaneous vaginal delivery in term singleton pregnancies: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the diagnostic performance of transperineal ultrasound-measured angles of progression at the onset of the second stage of labor for the prediction of spontaneous vaginal delivery in singleton term pregnancies with cephalic presentation.

DATA SOURCES

We performed a predefined systematic search in PubMed, Embase, Scopus, Web of Science, and Google Scholar from inception to February 5, 2021.

STUDY ELIGIBILITY CRITERIA

Prospective cohort studies that evaluated the diagnostic performance of transperineal ultrasound-measured angles of progression (index test) at the onset of the second stage of labor (ie, when complete cervical dilation is diagnosed) for the prediction of spontaneous vaginal delivery (reference standard) were eligible for inclusion. Eligible studies were limited to those published as full-text articles in the English language and those that included only parturients with a singleton healthy fetus at term with cephalic presentation.

STUDY APPRAISAL AND SYNTHESIS METHODS

Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary receiver operating characteristic curves, pooled sensitivities and specificities, area under the curve, and summary likelihood ratios were calculated using the Stata software. Subgroup analyses were done based on angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°.

RESULTS

A total of 8 studies reporting on 887 pregnancies were included. Summary estimates of the sensitivity and specificity of transperineal ultrasound-measured angle of progression at the onset of the second stage of labor for predicting spontaneous vaginal delivery were 94% (95% confidence interval, 88%-97%) and 47% (95% confidence interval, 18%-78%), respectively, for an angle of progression of 108° to 119°, 81% (95% confidence interval, 70%-89%) and 73% (95% confidence interval, 57%-85%), respectively, for an angle of progression of 120° to 140°, and 66% (95% confidence interval, 56%-74%) and 82% (95% confidence interval, 66%-92%), respectively, for an angle of progression of 141° to 153°. Likelihood ratio syntheses gave overall positive likelihood ratios of 1.8 (95% confidence interval, 1-3.3), 3 (95% confidence interval, 2-4.7), and 3.7 (95% confidence interval, 1.7-8.1) and negative likelihood ratios of 0.13 (95% confidence interval, 0.07-0.22), 0.26 (95% confidence interval, 0.18-0.38), and 0.42 (95% confidence interval, 0.29-0.60) for angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°, respectively.

CONCLUSION

Angle of progression measured by transperineal ultrasound at the onset of the second stage of labor may predict spontaneous vaginal delivery in singleton, term, cephalic presenting pregnancies and has the potential to be used along with physical examinations and other clinical factors in the management of labor and delivery.

Evidence-based labor management: second stage of labor (part 4)

Several interventions during the second stage of labor have been identified and investigated. Prophylactic intrapartum betamimetics should be avoided, as their usage is associated with an increase in operative vaginal deliveries. Women without epidural anesthesia are recommended to give birth in in any upright or lateral position. The best position for giving birth in women with epidural anesthesia is insufficiently studied, and neither recumbent nor upright positions can therefore be recommended. The routine use of maternal stirrups in the second stage of labor is not recommended. Consider avoiding water immersion during the second stage of labor, as the risks have not been adequately assessed. In nulliparous women at term with epidural analgesia, delayed pushing is not recommended. Pushing via a woman's own urge to push (open glottis) or pushing using the Valsalva maneuver (closed glottis) can both be considered. Both traditional coaching during pushing and ultrasound-assisted coaching may be considered. The use of a dental support device can be considered. All forms of fundal pressure are not recommended in the second stage of labor. Perineal massage and stretching of the perineum with a water-soluble lubricant in the second stage of labor is recommended. Perineal hyaluronidase injection as a method to reduce perineal trauma is not recommended. The use of perineal gel in the second stage of labor is not recommended. The use of perineal warm packs and heating pads are recommended. A perineal protection device can be considered. In fetuses with persistent occiput posterior position, manual rotation can be considered. Routine use of the Ritgen's maneuver does not seem to be associated with any benefits and is not recommended. The "Hands-poised" position is recommended over the "hands-on" method for delivery of the fetus. Routine episiotomy is not recommended. The routine use of ultrasound in the second stage of labor is not recommended. Waiting 1 additional hour (4 hours) for nulliparous women with epidural anesthesia before the diagnosis of a prolonged second stage of labor is recommended. A mandatory second opinion before cesarean delivery in the second stage of labor is recommended.

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.

The maternal pelvic floor and labor outcome

Vaginal birth is the major cause of pelvic floor damage. The development of transperineal ultrasound has improved our understanding of the relationship between vaginal birth and pelvic floor dysfunction. The female pelvic floor dimensions and function can be assessed reliably in pregnant women. Maternal pushing associated with pelvic floor muscle relaxation is the central requirement of vaginal birth. Many studies have evaluated the role of the pelvic floor on labor outcomes. Smaller levator hiatal dimensions and incomplete or absent levator ani muscle relaxation seem to be associated with a longer duration of the second stage of labor and a higher risk of cesarean and operative deliveries. Here, we presented an overview of the current knowledge of the correlation between female pelvic floor dimension and function, as assessed by transperineal ultrasound, and labor outcome.

Intrapartum ultrasound and the choice between assisted vaginal and cesarean delivery

Inaccurate assessment of the fetal head position and station might increase the risk for difficult or failed assisted vaginal delivery. Compared with digital vaginal examination, an ultrasound examination is objective and more accurate. The International Society of Ultrasound in Obstetrics and Gynecology has issued practical guidelines on intrapartum ultrasound in 2018 and recommended that an ultrasound assessment should be conducted when there is suspected delay or arrest of the first or second stage of labor or before considering assisted vaginal delivery. Fetal head position is assessed transabdominally by identifying the fetal occiput, orbit, or midline cerebral echo. Studies have shown that ultrasound assessment improved the correct diagnosis of fetal head position and accuracy of instrument placement, however, it did not reduce morbidity. Studies on ultrasound assessment of asynclitism are limited but show promising results. Fetal head station is assessed transperineally in the midsagittal or axial plane. Of the various ultrasound parameters, angle of progression and head-perineum distance are the most widely studied and found to be highly correlated with the clinical fetal head station. An angle of progression of 120° correlates with a clinical head station of 0 and is an important landmark for engagement of successful vaginal delivery, whereas an angle of progression of 145° correlates with a clinical head station of ≥+2 and has been associated with successful assisted vaginal delivery. In contrast, a head perineum distance of ≥40 mm has been associated with an increased risk for difficult assisted vaginal delivery. A "head-up" direction of descent assessed transperineally in sagittal plane is also a favorable factor for successful vaginal delivery. Current evidence seems to suggest that a prediction model with >1 sonographic parameter performed better than a model that only used 1 parameter. We suggest that an algorithm model incorporating both clinical and sonographic parameters would be useful in guiding clinicians on their decision for assisted vaginal delivery.

The continuum of a prolonged labor and a second stage cesarean delivery

OBJECTIVE

To investigate the association of the timing of primary cesarean delivery with the progress of labor and the operative delivery rate at the subsequent successful trial of labor.

METHODS

A retrospective study of women with a primary cesarean and subsequent term cephalic vaginal delivery in two medical centers. Cesarean deliveries were classified as planned, intrapartum first stage or intrapartum second stage. The second stage duration and the operative delivery rate, adjusted to epidural analgesia and oxytocin use, were compared between the groups. χ² and Kruskal-Wallis tests were used for analysis of categorical and continuous variables, respectively.

RESULTS

The study population included 1166 women. The second stage of labor was longer when the previous cesarean delivery occurred during the second stage compared to planned or first stage (1.7 h vs 1.3 h vs 1.3 h, p = 0.005). The proportion of operative deliveries was greater among women with previous cesarean in the second stage of labor (39.6%), compared to planned (26.9%) or first stage (28.8%), p = 0.006.

CONCLUSION

Cesarean delivery at the second stage of labor is associated with a longer second stage and an increased operative delivery rate at the subsequent vaginal birth. Our findings attest to the delicate passenger-passage relations that can exist in some parent-couples.

Are we preventing the primary cesarean delivery at the second stage of labor following ACOG-SMFM new guidelines? Retrospective cohort study

OBJECTIVE

In 2014, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal Fetal Medicine (SMFM) published an Obstetric Care Consensus for safe prevention of primary cesarean delivery. We aimed to assess whether these guidelines decreased the primary CD rate during the second stage of labor, in our department.

DESIGN, SETTING, AND POPULATION

A retrospective cohort study of all women reaching the second stage of labor, at term, in a single university-affiliated medical center between2010 and 2017.

METHODS

We compared maternal and neonatal outcomes over three year's periods:-pre-guidelines (2010-2013) vs. 2nd period - post-guidelines (2014-2017).

THE MAIN OUTCOME MEASURES

CD rate at 2ndstage of labor.

RESULTS

The study included 11,464 women. The CD rate in the 2nd stage of labor has increased significantly from 4% to 5.9% in the post-guidelines period (OR 1.48, 95% CI 1.16-1.89, p = .001). After a sub-analysis of specific subgroups, and adjustment for confounders, the increase was solely observed in nulliparous women (aOR 1.418, 95% CI 1.067-1.885, p = .016). Furthermore, increased odds for vaginal operative delivery were observed in the multiparous women in the post-guidelines period (2.7% vs. 4.1%, p = .046).

CONCLUSIONS

The implementation of the new ACOG and SMFM guidelines was not associated with a change in the CD rate performed at the 2nd stage of labor in the whole study population. However, there was a rise in the CD rate performed at the 2nd stage in nulliparous women. Furthermore, there was an increase in operative deliveries in the whole study population, especially in multiparous women, without an apparent increase in other immediate adverse neonatal or maternal outcomes.

Incidence of second-stage (fully dilated) cesarean sections and how best to represent it: A multicenter analysis

OBJECTIVE

To gather multicenter data on the incidence of second-stage cesarean sections and suggest alternative methods by which the data can be represented.

METHODS

Retrospective, observational study over a 12-month study period. Numbers of term, singleton live births were collated from each of six maternity units. Data were separated by mode of delivery-unassisted vaginal birth, assisted (instrumental) vaginal delivery and elective, first-stage, and second-stage cesarean sections. Second-stage cesarean sections were expressed as a proportion of all deliveries, of all laboring women (i.e. excluding elective cesarean sections), and all women who reach full dilatation (i.e. excluding elective and first-stage cesarean sections).

RESULTS

Of the 28 867 deliveries included in the analysis, 493 of these were second-stage cesarean sections. This represented an incidence of 1.7% of all deliveries, 2.0% of all women in labor, and 2.5% of all women who reach full dilatation.

CONCLUSION

Second-stage cesarean sections continue to be common. Safe delivery of a deeply impacted fetal vertex is essential in modern obstetric practice.

Obesity, Second Stage Duration, and Labor Outcomes in Nulliparous Women

OBJECTIVE

This study aimed to estimate second stage duration and its effects on labor outcomes in obese versus nonobese nulliparous women.

STUDY DESIGN

This was a secondary analysis of a cohort of nulliparous women who presented for labor at term and reached complete cervical dilation. Adjusted relative risks (aRR) were used to estimate the association between obesity and second stage characteristics, composite neonatal morbidity, and composite maternal morbidity. Effect modification of prolonged second stage on the association between obesity and morbidity was assessed by including an interaction term in the regression model.

RESULTS

Compared with nonobese, obese women were more likely to have a prolonged second stage (aRR: 1.48, 95% CI: 1.18-1.85 for ≥3 hours; aRR: 1.65, 95% CI: 1.18-2.30 for ≥4 hours). Obesity was associated with a higher rate of second stage cesarean (aRR: 1.78, 95% CI: 1.34-2.34) and cesarean delivery for fetal distress (aRR: 2.67, 95% CI: 1.18-3.58). Obesity was also associated with increased rates of neonatal (aRR: 1.38, 95% CI: 1.05-1.80), but not maternal morbidity (aRR: 1.06, 95% CI: 0.90-1.25). Neonatal morbidity risk was not modified by prolonged second stage.

CONCLUSION

Obesity is associated with increased risk of neonatal morbidity, which is not modified by prolonged second stage of labor.

Transperineal ultrasound assessment of maternal pelvic floor at term and fetal head engagement

OBJECTIVES

To evaluate the association between pelvic floor dimensions in nulliparous women at term and fetal head engagement, as assessed by transperineal ultrasound.

METHODS

This was a prospective observational study of nulliparous women at term. Before the onset of labor, transperineal ultrasound was used to measure the anteroposterior diameter (APD) of the levator hiatus and the angle of progression (AoP) at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver (before and after visual feedback). We assessed the correlation between pelvic floor static and dynamic dimensions (levator hiatal APD and levator ani muscle coactivation) and AoP, which is an objective index of fetal head engagement.

RESULTS

In total, 282 women were included in the analysis. Among these, 211 (74.8%) women had a vaginal delivery while 71 (25.2%) had a Cesarean delivery. AoP was narrower in the Cesarean-delivery group at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva, whereas no differences in levator hiatal APD were found between the two groups. We found a negative correlation between levator hiatal APD at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva and the duration of the second stage of labor. There was a positive correlation between AoP and levator hiatal APD on maximum Valsalva maneuver after visual feedback (r = 0.15, P = 0.01). Women with levator ani muscle contraction on Valsalva maneuver (i.e. coactivation), both pre and post visual feedback, had a narrower AoP at rest and on maximum Valsalva. After visual feedback, women with levator ani muscle coactivation had a longer second stage of labor than did those without (80.8 ± 61.4 min vs 62.9 ± 43.4 min (P = 0.04)).

CONCLUSIONS

Smaller pelvic floor dimensions and levator ani muscle coactivation are associated with higher fetal head station and with a longer second stage of labor in nulliparous women at term. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Neonatal outcome of second-stage cesarean delivery versus vacuum extraction among neonates <34 weeks

OBJECTIVE

Among deliveries <34 weeks, there is inconclusive evidence regarding the preferred route of delivery when there is a need to expedite delivery during the second stage of labor. As it is unreasonable that future randomized controlled trials will be conducted to settle this query, every clinical data concerning this topic, may be helpful. We aim to compare neonatal outcomes among women undergoing emergent cesarean delivery (ECD) versus vacuum-assisted delivery (VAD) during the second stage of labor among singleton gestations <34 weeks.

METHODS

A retrospective cohort study including all women who underwent either ECD or VAD at the second stage of labor between 30°^/7 and 33^6/7weeks, during 2011-2019. The primary outcome was the rate of adverse neonatal outcomes, defined as intrapartum death, mechanical ventilation, asphyxia, respiratory distress syndrome, subgaleal hemorrhage, intraventricular hemorrhage, necrotizing enterocolitis, and phototherapy.

RESULTS

Of the 153,672 live singleton deliveries during the study period, 2871 (1.9%) delivered before 34°^/7. Of those 1674 (58.3%) delivered vaginally unassisted and 1137 (39.6%) delivered by a CD during the first stage of labor. A total of 60 deliveries were analyzed, with a median gestational age of 32 weeks, interquartile range (IQR) 31-33. Median birth weight at delivery was 1845 g, IQR 1574-2095. Overall 25 (42%) of women were delivered by VAD and 35 by CD (58%). Indications for expeditious delivery did not differ between the study groups. Neonates delivered by VAD had a higher median birth weight (1940 vs. 1620 g, p = .02). Second stage of labor was longer in the ECD group as compared to the VAD group (median 200 vs. 52 min, p = .01). The rate of Apgar score at 1 min <7 was higher among the CD group (10 (40%) vs. 5 (14%), OR [95% CI]: 4.0 (1.1-13.8), p = .03). Longer length of stay was evident in the CD group as compared to the VAD group (median 30 vs. 21 days, p = .001). The rate of composite neonatal adverse outcome was comparable between the study groups. Adverse outcomes were associated with lower body mass index (median 27.7 vs. 34.9, p = .04), higher rate of premature preterm rupture of membranes (40 (91%) vs. 5 (31%), OR [95% CI]: 22.0 (5.0-91.1), p < .001) and labor dystocia as the indication for expedited delivery (38 (86%) vs. 7 (44%), OR [95% CI]: 8.1 (2.1-30.1), p = .001).

CONCLUSIONS

Cesarean delivery during the second stage of labor of gestations <34 weeks was associated with a higher rate of lower Apgar scores and longer length of stay.

SYNOPSIS

Delivery by second stage CD of premature neonates <34 weeks is associated with a higher rate of lower Apgar score.

New technique for automatic sonographic measurement of change in head-perineum distance and angle of progression during active phase of second stage of labor

OBJECTIVE

To evaluate the performance of a new ultrasound technique for the automatic assessment of the change in head-perineum distance (delta-HPD) and angle of progression (delta-AoP) during the active phase of the second stage of labor.

METHODS

This was a prospective observational cohort study including singleton term pregnancies with fetuses in cephalic presentation during the active phase of the second stage of labor. In each patient, two videoclips of 10 s each were acquired transperineally, one in the axial and one in the sagittal plane, between rest and the acme of an expulsive effort, in order to measure HPD and AoP, respectively. The videoclips were processed offline and the difference between the acme of the pushing effort and rest in HPD (delta-HPD) and AoP (delta-AoP) was calculated, first manually by an experienced sonographer and then using a new automatic technique. The reliability of the automatic algorithm was evaluated by comparing the automatic measurements with those obtained manually, which was considered as the reference gold standard.

RESULTS

Overall, 27 women were included. A significant correlation was observed between the measurements obtained by the automatic and the manual methods for both delta-HPD (intraclass correlation coefficient (ICC) = 0.97) and delta-AoP (ICC = 0.99). The high accuracy provided by the automatic algorithm was confirmed by the high values of the coefficient of determination (r²  = 0.98 for both delta-HPD and delta-AoP) and the low residual errors (root mean square error = 1.2 mm for delta-HPD and 1.5° for delta-AoP). A Bland-Altman analysis showed a mean difference of 0.52 mm (limits of agreement, -1.58 to 2.62 mm) for delta-HPD (P = 0.034) and 0.35° (limits of agreement, -2.54 to 3.09°) for delta-AoP (P = 0.39) between the manual and automatic measurements.

CONCLUSIONS

The automatic assessment of delta-AoP and delta-HPD during maternal pushing efforts is feasible. The automatic measurement of delta-AoP appears to be reliable when compared with the gold standard manual measurement by an experienced operator. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

The dynamic change of the anteroposterior diameter of the levator hiatus under Valsalva maneuver at term and labor outcome

AIM

The aim of the present study was to evaluate the correlation between the proportional change of anteroposterior diameter (APD) of levator hiatus from rest to maximum Valsalva maneuver in nulliparous women at term and labor outcome.

METHODS

We prospectively recruited nulliparous women at term before the onset of labor. Women underwent a two-dimensional transperineal ultrasound, measuring the APD of the levator hiatus at rest and under maximum Valsalva's maneuver. APD change from rest to maximum Valsalva was described both in terms of absolute figures and proportional change. Correlation of APD change with the mode of delivery and with labor durations was assessed.

RESULTS

Overall, 486 women were included in the analysis. No significant association between change in APD and the mode of delivery. We found a significant negative correlation between change of APD from rest to Valsalva and the duration of active second stage both in terms of absolute change (Pearson's r = -0.138, P = .009) and in terms of proportional change (Pearson's r = -0.154, P = .004). Survival outcomes based on Cox-regression model showed that APD was independently associated with the duration of active second stage of labor after adjusting for epidural analgesia, maternal age and body mass index (hazard ratio, 1.008; 95% confidence interval, 1.001-1.016; P = .04) CONCLUSION: Women with higher increase of the anteroposterior diameter of the levator hiatus from rest to Valsalva have a shorter active second stage of labor.

Delayed versus immediate pushing in the second stage of labor in women with neuraxial analgesia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this systematic review and meta-analysis of randomized controlled trials was to evaluate the effect of delayed versus immediate pushing in the second stage of labor on mode of delivery and other outcomes in women with neuraxial analgesia.

DATA SOURCES

The research was conducted using MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and the Cochrane Library as electronic databases, from the inception of each database to August 2019. No restrictions for language or geographic location were applied.

STUDY ELIGIBILITY CRITERIA

Selection criteria included only randomized controlled trials in pregnant women randomized to either delayed or immediate pushing during the second stage of labor.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was mode of delivery. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I² (Higgins I²) value of greater than 0% was used to identify heterogeneity.

RESULTS

Twelve randomized controlled trials, including 5445 women with neuraxial analgesia randomized to delayed versus immediate pushing during the second stage of labor, were included in the meta-analysis. Of the 5445 women included in the meta-analysis, 2754 were randomized to the delayed pushing group and 2691 to the immediate pushing group. No significant difference between delayed and immediate pushing was found for spontaneous vaginal delivery (80.9% versus 78.3%; relative risk, 1.05; 95% confidence interval, 1.00-1.10; 12 randomized controlled trials, 5540 women), operative vaginal delivery (12.8% versus 14.6%; relative risk, 0.89; 95% confidence interval, 0.75-1.08; 11 randomized controlled trials, 5395 women), and cesarean delivery (6.9% versus 7.9%; relative risk, 0.89; 95% confidence interval, 0.73-1.07; 11 randomized controlled trials; 5395 women). Women randomized to the delayed pushing group had a significantly shorter length of active pushing (mean difference, -27.54 minutes; 95% confidence interval, -43.04 to -12.04; 7 randomized controlled trials, 4737 women) at the expense of a significantly longer overall duration of the second stage of labor (mean difference, 46.17 minutes; 95% confidence interval, 32.63-59.71; 8 studies; 4890 women). The incidence of chorioamnionitis (9.1% versus 6.6%; relative risk, 1.37, 95% confidence interval, 1.04-1.81; 1 randomized controlled trial, 2404 women) and low umbilical cord pH (2.7% versus 1.3%; relative risk, 2.00; 95% confidence interval, 1.30-3.07; 5 randomized controlled trials, 4549 women) were significantly higher in the delayed pushing group.

CONCLUSION

In women with spontaneous or induced labor at term with neuraxial analgesia, delayed pushing in the second stage does not affect the mode of delivery, although it reduces the time of active pushing at the expense of a longer second stage. This prolongation of labor was associated with a higher incidence of chorioamnionitis and low umbilical cord pH. Based on these findings, delayed pushing cannot be routinely advocated for the management of the second stage.

Fetal extraction maneuvers during cesarean delivery in the second stage of labor

Objective: To compare maternal and neonatal outcomes following cesarean delivery during second stage of labor, according to the fetal extraction method.Methods: A retrospective cohort study of all women who underwent term cesarean delivery during the second stage of labor at a university-affiliated tertiary medical center (2012-2016). The cohort was divided according to three extraction methods: standard vertex extraction, the push method in which the head extraction is accompanied by pushing through the vagina, and the reverse breech extraction method. Primary outcomes were intraoperative maternal complications, and secondary outcomes were neonatal adverse events.Results: Three hundred and fifty women were included, of whom 206 (59%) underwent standard vertex fetal extraction, 116 (33%) the push method extraction, and 28 (8%) reverse breech extraction. Operation time was significantly shorter in the standard vertex extraction method compared to push and reverse breech extraction methods (33.5 vs. 40.5 and 39.0 min, respectively, p = .013). Uterine laceration and incision extension frequencies were lower in the vertex extraction method as well (24.76 vs. 45.69-46.40% in others, p < .001). Delivery related neonatal injury was significantly more frequent in the reverse breech extraction method (39.29 vs. 12-15% in others, p < .001). In a multivariate analysis reverse breech extraction was associated with higher rates of uterine laceration and incision extension (OR = 2.739 95% confidence interval 1.44-6.56, p = .0237) and delivery related neonatal injury (OR = 2.837, 95% CI: 1.081-7.448, p = .0342).Conclusion: Standard vertex extraction method during second stage of labor cesarean delivery is safer both to the mother and neonate when compared to alternative extraction methods.Abbreviations: NRFHR: non-reassuring fetal heart rate; NICU: neonatal intensive care unit.

Redefining Second Stage of Labor: Number of Pushing Contractions

Introduction  Despite time standards for second stage labor, "delayed pushing," uterine contraction frequency, and alternate contraction pushing may alter the effective maternal effort. We sought to quantify the number of pushing contractions needed for a spontaneous vaginal delivery (SVD) among primipara and multipara patients. Methods  Deliveries at Harbor-UCLA Medical Center in 2017 were selected for SVD of singleton, term newborns. The first 100 primipara and 100 multipara deliveries were analyzed and monitor tracings quantified for pushing contractions. Results  Significantly more pushing contractions were required by primiparas versus multiparas (17.3 ± 1.7 vs. 5.5 ± 0.7; p  < 0.001) in accord with a longer second stage (86.7 ± 7.8 vs. 27.2 ± 4.9 min; p  < 0.001) and epidural was associated with greater number of pushing contractions among both primipara (18.5 ± 1.8 vs. 10.8 ± 0.8) and multipara women (6.1 ± 0.8 vs. 4.1 ± 0.3). Newborn weight (<3000, 3000-3500, >3500 g) demonstrated a trend for increased pushing contractions among primipara (16.9, 16.5, 19.8 pushes, respectively) though not multiparas. Conclusion  Although correlated with the absolute duration of the second stage, the number of pushing contractions eliminates ambiguities of "delayed pushing," pushing every-other, and frequency of contractions. Examination of larger databases and patients with second stage "arrest disorders" may provide pushing contraction criteria predictive of SVD and prevention of morbidity.

Defining the upper limit of the second stage of labor in nulliparous patients

BACKGROUND

Increased duration of the second stage of labor provides clinical challenges in decision-making regarding the optimal mode of delivery that minimizes maternal and neonatal morbidity.

OBJECTIVE

In a large cohort of uncomplicated nulliparous singleton cephalic labors, we sought to examine the effect of increasing duration of second stage on delivery and perinatal outcome.

STUDY DESIGN

The GENESIS Study recruited 2336 nulliparous patients with vertex presentation in a prospective double-blinded study to examine prenatal and intrapartum predictors of delivery. Metrics included maternal demographics, duration of second stage, mode of delivery, and associated maternal and neonatal outcomes. Indicators of morbidity included third- or fourth-degree tear, postpartum hemorrhage, neonatal intensive care unit admission, low Apgar scores, cord pH <7.20 and a composite of birth injury that included cephalohematoma, fetal laceration, brachial plexus palsy, facial nerve palsy, and fetal fracture.

RESULTS

Of 2336 recruited nulliparous participants, 1872 reached the second stage of labor and had complete data for analysis. Increased maternal age (P=.02) and birthweight (P<.001) were found to be associated with a longer second stage. Increasing second stage duration was found to impact on mode of delivery, such that at <1 hour duration the spontaneous vaginal delivery rate was 63% vs 24% at >3 hours (P<.001). Operative vaginal delivery increased from 35% at <1 hour to 65% at >3 hours (P<.001). The rate of cesarean delivery increased with duration of the second stage from 1.2% at <1 hour to 11% at >3 hours (P<.001). The rates of third- or fourth-degree tear increased with second stage duration (P=.003), as did postpartum hemorrhage (P<.001). The composite neonatal birth injury rate increased from 1.8% at <1 hour to 3.4% at >3 hours. The maximum rate of birth injury was 6.5% at 2-3 hours (P<.001). Multiple logistic regression analysis that controlled for maternal age and birthweight confirmed that operative vaginal delivery, perineal trauma, postpartum hemorrhage, and neonatal birth injury remained significantly more likely with increasing second stage duration.

CONCLUSION

In a prospective cohort of nulliparous pregnancies, increasing duration of second stage of labor was associated with increased rates of operative vaginal and cesarean delivery. Although almost 90% of term nulliparous women with a second stage of labor >3 hours will succeed in achieving a vaginal birth, this success comes at a maternal morbidity cost, with a 10% risk of severe perineal injury and an increasing rate of significant neonatal injury.

Hands-on versus hands-off techniques for the prevention of perineal trauma during vaginal delivery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Perineal trauma at the time of vaginal delivery is common, and when the anal sphincter is included, these injuries can be associated with additional morbidity including incontinence, pelvic pain, and sexual dysfunction.

OBJECTIVE

The aim of this systematic review with meta-analysis was to evaluate whether a hands-on technique during vaginal delivery results in less incidence of perineal trauma than a hands-off technique.

METHODS

Electronic databases were searched from their inception until June 2018. No restrictions for language or geographic location were applied. The reference lists of identified articles were examined to identify studies not captured by electronic searches. Randomized controlled trials comparing a hands-on technique of perineal support during vaginal delivery (i.e. intervention group) with a hands-off technique (i.e. control group) were included in the meta-analysis. Hands-on was defined as involving one hand on the fetal head, applying pressure to control expulsion, with the other hand applying pressure on the maternal perineum. The primary outcome was severe perineal trauma, defined as either third- or fourth-degree lacerations. The meta-analysis was performed using the random effects model of DerSimonian and Laird, to produce summary treatment effects in terms of relative risk (RR) with 95% confidence interval (CI).

RESULTS

Five trials, including 7287 women, were analyzed. All studies included singleton gestations with cephalic presentation at term undergoing spontaneous vaginal delivery. Women randomized to the hands-on technique had similar incidence of severe perineal trauma (1.5 versus 1.3%; RR 2.00, 95% CI 0.56-7.15). There was no significant between-group difference in the incidence of intact perineum, first-, second- and fourth-degree laceration. Hands-on technique was associated with increased risk of third-degree lacerations (2.6 versus 0.7%; RR 3.41, 95% CI 1.39-8.37) and of episiotomy (13.6 versus 9.8%, RR 1.59, 95% CI 1.14-2.22) compared to the hands-off technique.

CONCLUSIONS

Hands-on technique during spontaneous vaginal delivery of singleton gestations results in similar incidence of several perineal traumas compared to a hands-off technique. The incidence of third-degree lacerations and of episiotomy increases with the hands-on technique. Key Message A hands-on technique during vaginal delivery results in similar incidence of severe lacerations compared to hands-off.

Pushing the limits: perinatal outcomes beyond prolonged second stage

Objective: To evaluate whether extremely prolonged second stage of labor in nulliparous women affects mode of delivery and perinatal outcomes.Methods: We performed a retrospective cohort study of nulliparous women with singleton gestations and cephalic presentation who reached 10 cm of cervical dilation at gestational age 36 0/7-41 6/7. Women were stratified by epidural status. Deliveries were compared by length of second stage: 0-179 min (normal second stage, NSS), 180-299 min (prolonged second stage, PSS), and ≥300 min (extremely prolonged second stage, EPSS). Primary outcome was incidence of vaginal delivery. Secondary outcomes were maternal and neonatal morbidities.Results: Six hundred sixty-one women were evaluated; overall, 92.7% (613/661) of the patients delivered vaginally, with 84.6% (559/661) of women undergoing spontaneous vaginal delivery. In women with epidural anesthesia, 90.6% (446/492) delivered vaginally (97.2% of NSS, 95.1% of PSS, and 69.2% of EPSS). In women without epidural anesthesia, 98.8% (167/169) delivered vaginally (99.3% of NSS, 100.0% of PSS, and 87.5% of EPSS). Women with epidural anesthesia and EPSS had a higher rate of postpartum hemorrhage (aOR: 8.52; 95% CI: 3.99-18.19) and third-degree laceration when compared to NSS (aOR: 5.87; 95% CI: 1.71-20.17). EPSS neonates had a higher rate of CPAP use (OR: 3.99; 95% CI: 1.82-8.74) and significantly higher birth weight (p < .0001) and composite neonatal outcomes (OR: 4.98; 95% CI: 2.34-10.59) compared to NSS.Conclusion: In nulliparous women at term with singleton gestations who reached second stage, the chance of vaginal delivery was 92.7%; even after 5 h of second stage, most women delivered via vaginal delivery (70.4%, 81/115). In those with epidural anesthesia, the PSS group had similar perinatal outcomes as the NSS group, whereas the EPSS group had significantly worse perinatal outcomes. Second stage ≥5 h is a potential tipping point for hazardous perinatal outcomes.

Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

OBJECTIVE

To assess the effect of levator ani muscle (LAM) coactivation at term on outcome of labor in nulliparous women.

METHODS

This was a prospective study of 284 low-risk nulliparous women with a singleton pregnancy at term recruited before the onset of labor. The anteroposterior diameter of the levator hiatus was measured in each woman on transperineal ultrasound at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver before and after visual feedback. LAM coactivation was defined as a reduction in the anteroposterior diameter of the levator hiatus on maximum Valsalva maneuver in comparison with that at rest. The association of pelvic hiatal diameter values and LAM coactivation with mode of delivery and duration of labor was assessed.

RESULTS

No significant difference was found between women who underwent Cesarean delivery and those who had a vaginal delivery with regard to the anteroposterior diameter of the levator hiatus at rest, on pelvic floor muscle contraction and on Valsalva maneuver. Longer second stage of labor was associated with shorter anteroposterior diameter of the levator hiatus on all assessments, but in particular at rest and on Valsalva both before and after visual feedback. LAM coactivation was found in 89 (31.3%) and 75 (26.4%) women before and after visual feedback, respectively. Post visual feedback, women with LAM coactivation had a significantly longer second stage of labor than did those without LAM coactivation (83 ± 63 vs 63 ± 42 min; P = 0.006). On Cox regression analysis, LAM coactivation post visual feedback was an independent predictor of longer second stage of labor (adjusted hazard ratio, 1.499 (95% CI, 1.076-2.087); P = 0.017).

CONCLUSION

LAM coactivation in nulliparous women at term is associated with a longer second stage of labor. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The impact of epidural analgesia on the duration of the second stage of labor

BACKGROUND

We aimed to describe the length of second stage of labor in a contemporary cohort. We calculated the 5th, 50th, and 95th percentiles for second-stage length stratified by parity and epidural analgesia use and evaluated the effect of labor induction and oxytocin augmentation in our cohort.

METHODS

We did a retrospective analysis of all live, singleton, term vaginal deliveries in one tertiary hospital. Multivariate linear regression was used to evaluate second-stage duration confounders. First, we calculated the second-stage length and presented it as 5th, 50th, and 95th percentiles stratified by epidural analgesia and parity. Second, we evaluated the effect of labor induction and oxytocin augmentation on second-stage length, and third, we determined the demographic and obstetrical confounders that affected second-stage length.

RESULTS

Overall, 15 500 deliveries were included. Nulliparity, oxytocin augmentation, epidural use, birthweight, labor induction, lower body mass index, and higher maternal age were found to be significantly associated with prolongation of the second stage. Epidural use was associated with an additional 82 minutes for the 95th percentile for both nulliparas and multiparas and tripled the rate of prolonged second stage for the entire cohort. Labor induction was associated with clinically significant prolongation of the second stage in nulliparas with epidural analgesia only. Oxytocin was associated with longer duration of the second stage for nulliparas, regardless of epidural use.

DISCUSSION

Our findings suggest a significant prolongation of the second stage in women receiving epidural analgesia. Recommendations for management of second stage should be reconsidered by contemporary data.

Emergent primary cesarean delivery and maternal operative morbidity

BACKGROUND

It is unknown how variations in surgical entry time in primary cesarean delivery (CD) may affect operative outcomes and maternal morbidity.

OBJECTIVE

Determine whether performing a primary CD in labor emergently ("stat") is associated with adverse maternal outcomes.

STUDY DESIGN

Retrospective cohort study of patients who underwent primary CD at The Mount Sinai Hospital during the years of 2011-2016. Women with a singleton pregnancy and without a prior uterine scar attempting a trial of labor were included. An emergent CD was defined as a skin-to-uterine incision (I-U) time of ≤3 minutes. Subjects were dichotomized into those with an I-U time of ≤3 minutes or ≥5 minutes.

RESULTS

1722 patients underwent primary CD and met eligibility criteria. 72 patients with an I-U time of 4 minutes were removed from the analysis. 196 patients (11.9%) had an I-U time ≤3 minutes and 1454 patients (88.1%) had an I-U time ≥5 minutes. There were no differences in any outcomes between groups. The likelihood of transfusion, hysterectomy, or admission to the intensive care unit (ICU) was 1.5% in the emergent group and 1.0% in the control group (p = .334). Postpartum length of stay was also similar between the groups (3.3 versus 3.2 days, p = .259). When 384 patients with I-U times >10 minutes were excluded, surgical outcomes remained similar between groups. Among the subgroup of patients who reached the second stage of labor, surgical outcomes were also similar between groups.

CONCLUSIONS

Emergent primary CD is not associated with increased maternal morbidity.

Passive descent in the second stage: evaluation of variation in practice patterns. J Matern Fetal Neonatal Med 2017;31:2271-2275. [PMID: 28605943 DOI: 10.1080/14767058.2017.1340448]

OBJECTIVE

To compare the length of the second stage in nulliparous women with respect to a range of factors related to staffing and outcomes at a community hospital.

METHODS

This was a retrospective cohort study of nulliparous women presenting for delivery over a 2-year period. The primary outcomes were the presence of passive descent and length of the second stage. Secondary outcomes were mode of delivery, chorioamnionitis, and postpartum hemorrhage.

RESULTS

Passive descent was observed in 198 women in the second stage. When passive descent occurred, the differences in the median length of the second stage in relation to the nursing shift increments were statistically significant, with the longest times corresponding to the middle 4 h of the nursing shifts (p = .046). Physician patients were more likely than midwife patients to undergo passive descent on weekdays (36% vs. 26%, p = .034) but not on weekends (32% for both). Though the likelihood of a vaginal delivery remained high up to 6 h into the second stage, the rate of hemorrhage and chorioamnionitis increased significantly.

CONCLUSIONS

When passive descent occurred, second stage length varied depending on the time of day. These findings suggest provider behaviors impact the length of the second stage.

A Prospective Randomized Trial of Postural Changes vs Passive Supine Lying during the Second Stage of Labor under Epidural Analgesia

There exist very few studies comparing different postures or postural changes during labor in parturients with epidural analgesia.

AIM

To disclose whether the intervention of a multidisciplinary nursing team including a physiotherapist during the second stage of labor improves the obstetric outcome in parturients with epidural analgesia.

DESIGN

Prospective randomized trial.

SETTING

University-affiliated hospital.

POPULATION

Women undergoing labor with epidural analgesia after a normal gestation.

METHODS

150 women were randomized either to actively perform predefined postural changes during the passive phase of the second stage of labor under the guidance of the attending physiotherapist (study group), or to carry out the whole second stage of labor lying in the traditional supine position (control group).

RESULTS

There were significantly more eutocic deliveries (p = 0.005) and, conversely, significantly less instrumental deliveries (p < 0.05) and cesarean sections (p < 0.05) in the study group. The total duration of the second stage of labor was significantly shorter (p < 0.01) in the study group. This was at the expense of the passive phase of the second stage of labor (p < 0.01). Significantly less episiotomies were performed in the study group (31.2% vs 17.8%, p < 0.05).

CONCLUSION

The intervention of a physiotherapist during the second stage of labor significantly improved the obstetric outcome.

Duration of Second Stage of Labour at Term and Pushing Time: Risk Factors for Postpartum Haemorrhage

BACKGROUND

Prolonged labour is associated with increased risk of postpartum haemorrhage (PPH), but the role of active pushing time and the relation with management during labour remains poorly understood.

METHODS

A population-based cohort study from electronic medical record data in the Stockholm-Gotland Region, Sweden. We included 57 267 primiparous women with singleton, term gestation, livebirths delivered vaginally in cephalic presentation in 2008-14. We performed multivariable Poisson regression to estimate the association between length of second stage, pushing time, and PPH (estimated blood loss >500 mL during delivery), adjusting for maternal, delivery, and fetal characteristics as potential confounders.

RESULTS

The incidence of PPH was 28.9%. The risk of PPH increased with each passing hour of second stage: compared with a second stage <1 h, the adjusted relative risk (RR) for PPH were for 1 to <2 h 1.10 (95% confidence interval (CI) 1.07, 1.14); for 2 to <3 h 1.15 (95% CI 1.10, 1.20); for 3 to <4 h 1.28 (95% CI 1.22, 1.33); and for ≥4 h 1.40 (95% CI 1.33, 1.46). PPH also increased with pushing time exceeding 30 min. Compared to pushing time between 15 and 29 min, the RR for PPH were for <15 min 0.98 (95% CI 0.94, 1.03); for 30-44 min 1.08 (95% CI 1.04, 1.12); for 45-59 min 1.11 (95% CI 1.06, 1.16); and for ≥60 min 1.20 (95% CI 1.15, 1.25).

CONCLUSIONS

Increased length of second stage and pushing time during labour are both associated with increased risk of PPH.

Fetal scalp blood lactate during second stage of labor: determination of reference values and impact of obstetrical interventions

OBJECTIVE

To determine the reference interval of fetal scalp blood lactate during second stage of labor.

MATERIAL

Two hundred and fifty-three women in first stage of labor with a reassuring CTG were asked for permission to sample fetal scalp blood during second stage.

RESULTS

In cases with reassuring CTG and five minute Apgar score ≥9, the mean lactate value (±2 SD) was 2.5 mmol/L (lower limit 1.1, higher limit 5.2). The lactate concentration was significantly higher among nulliparous and in cases with use of epidural or oxytocin (p <0.001). There was a moderate positive correlation between scalp lactate values and active pushing time. When parity, epidural, oxytocin and active pushing time were analyzed together, they had equal influence on lactate values (p <0.001). Higher lactate values were associated with intermediate/pathological CTG compared to normal CTG (p <0.001). There was no correlation to gestational age or birthweight (p = 0.72, respectively 0.43).

CONCLUSIONS

The reference interval of fetal scalp lactate during second stage is 1.1-5.2 mmol/L. Parity, use of epidural or oxytocin and the duration of pushing are associated to increased lactate concentration; however, we could not demonstrate any correlation to advancing gestational age or birthweight.

Prolonged second stage of labour, maternal infectious disease, urinary retention and other complications in the early postpartum period

Objective

To study the association between duration of second stage of labour and risks of maternal complications (infection, urinary retention, haematoma or ruptured sutures) in the early postpartum period.

Design

Population‐based cohort study.

Setting and sample

We included 72 593 mothers with singleton vaginal deliveries at ≥37 weeks of gestation in cephalic presentation, using the obstetric database from the Stockholm‐Gotland region in Sweden, 2008–12.

Methods

Logistic regression analysis. Odds ratios (ORs) with 95% confidence intervals (95% CI) were calculated and adjustments were made for maternal age, body mass index, height, smoking, cohabitation, gestational age, labour induction, epidural analgesia and oxytocin augmentation.

Results

Rates of any complication varied by parity from 7.3% in parous women with previous caesarean section, 4.8% in primiparas and 1.7% in parous women with no previous caesarean section. Compared with a second stage <1 hour, the adjusted ORs for any complication (95% CI) in primiparas were for 1 to <2 hours 1.28 (1.11–1.47); 2 to <3 hours 1.54 (1.32–1.79), 3 to <4 hours 1.63 (1.38–1.93) and ≥4 hours 2.08 (1.74–2.49). The corresponding adjusted ORs for parous women without previous caesarean were 2.27 (1.78–2.90), 2.97 (2.09–4.22), 3.65 (2.25–5.94) and 3.16 (1.44–6.94), respectively. The adjusted ORs for women with previous caesarean were for 1 to <2 hours 1.62 (1.13–2.32); 2 to <3 hours 1.56 (1.00–2.43), 3 to <4 hours 2.42 (1.52–3.87), and ≥4 hours 2.31 (1.25–4.24).

Conclusions

Risks of maternal complications in the postpartum period increase with duration of second stage of labour also after accounting for maternal, pregnancy and delivery characteristics. Special attention has to be given to parous women with previous caesarean deliveries.

Treatment options for second-stage gambiense human African trypanosomiasis

Treatment of second-stage gambiense human African trypanosomiasis relied on toxic arsenic-based derivatives for over 50 years. The availability and subsequent use of eflornithine, initially in monotherapy and more recently in combination with nifurtimox (NECT), has drastically improved the prognosis of treated patients. However, NECT logistic and nursing requirements remain obstacles to its deployment and use in peripheral health structures in rural sub-Saharan Africa. Two oral compounds, fexinidazole and SCYX-7158, are currently in clinical development. The main scope of this article is to discuss the potential impact of new oral therapies to improve diagnosis-treatment algorithms and patients' access to treatment, and to contribute to reach the objectives of the recently launched gambiense human African trypanosomiasis elimination program.

Infectious morbidity is higher after second-stage compared with first-stage cesareans

OBJECTIVE

The objective of the study was to compare maternal and neonatal infectious morbidity following cesareans performed in the second and first stages of labor.

STUDY DESIGN

We conducted a retropective cohort study of all consecutive, singleton, term, cesarean deliveries in laboring women in a single institution from 2005 to 2012. Second-stage cesareans were defined as those performed at complete cervical dilation (10 cm), and first-stage cesareans were those performed before 10 cm cervical dilation. The primary outcome was endometritis. Rates of infectious morbidity were compared in the 2 groups. Multivariable logistic regression was used to calculate adjusted risk estimates.

RESULTS

Of 2505 cesareans meeting inclusion criteria, 400 (16.0%) were performed in the second stage, whereas 2105 (84.0%) were performed in the first stage of labor. The risk of endometritis was nearly 3-fold higher in second- compared with first-stage cesareans (4.25% vs 1.52%; crude odds ratio, 2.88; 95% confidence interval, 1.58-5.23). The risk remained significantly higher after controlling for confounders (adjusted odds ratio, 2.78; 95% confidence interval, 1.51-5.09).

CONCLUSION

Second-stage cesarean is associated with an increased risk of endometritis compared with first-stage cesarean. Further studies will determine whether different infection preventive strategies are needed at second-stage cesareans to reduce endometritis.

Sonographic pattern of fetal head descent: relationship with duration of active second stage of labor and occiput position at delivery

OBJECTIVES

The objectives of this study were firstly to assess the longitudinal changes of various sonographic parameters of fetal head progression in relation to length of active second stage of labor, and secondly to compare ultrasound findings obtained longitudinally among fetuses with persistent occiput posterior (OP) vs those with persistent occiput anterior (OA) position.

METHODS

From a series of nulliparous low-risk women at term attending the labor ward of our university hospital, transperineal ultrasound volumes were prospectively acquired at the beginning of the active second stage (T1) and at 40-min intervals thereafter until delivery (T2, T3). Sonographic parameters were derived from offline analysis of each volume, including the angle of progression (AoP), progression distance (PD), head-symphysis distance (HSD), head direction (HD) and midline angle. These parameters were compared between patients who delivered within 60 min from the beginning of the active second stage of labor (early delivery) and those who remained undelivered by that time (late delivery). Fetal head position was determined from stored digital images of transabdominal examinations performed at the beginning of the active second stage. Comparison was performed between fetuses with OA and those with persistent OP position at delivery.

RESULTS

Spontaneous vaginal delivery was achieved in 58 (81.7%) cases, whereas vacuum extraction and Cesarean section were performed in eight (11.3%) and five (7.0%) cases, respectively. Delivery was achieved within 60 min from the beginning of the active second stage in 44 (62.0%) patients. In the early vs late delivery groups, measurements of AoP, HSD and PD at T1 were significantly different (AoP, 143.9 ± 20.5° vs 125.3 ± 15.0°, P < 0.001; HSD, 14.8 ± 4.5 mm vs 20.9 ± 5.8 mm, P < 0.001; PD, 44.0 ± 14.1 vs 35.0 ± 13.1 mm, P = 0.008). On logistic regression analysis of data obtained at T1, maternal body mass index, oxytocin administration, neonatal birth weight and HSD appeared to predict independently duration of the active second stage. Among fetuses delivering in the OP position (n = 10, 13.5%), Cesarean delivery was significantly more common than in those delivering in the OA position (n = 5 (50.0%) vs n = 2 (3.1%), P = 0.001). Women with persistent OP position compared with OA showed a significantly different AoP at T1 (122 ± 17° vs 138 ± 20°, P = 0.016), HD and HSD at T1 (HD, 112 ± 17 mm vs 86 ± 19 mm, P < 0.001; HSD, 16.5 ± 5.4 mm vs 22.8 ± 6.6 mm, P = 0.008) and at T2 (HD, 120 ± 16 vs 82 ± 27 mm, P = 0.008; HSD, 12.6 ± 3.4 mm vs 18.5 ± 5.4 mm, P = 0.038).

CONCLUSIONS

AoP, PD and HSD are significantly different between patients undergoing delivery before or after 60 min from the beginning of the active second stage of labor. Ultrasound parameters are among the significant predictors of duration of the active second stage. Moreover, in fetuses persisting in the OP position vs those delivering in the OA position, fetal head progression seems to differ at early phases of the active second stage.

Labor in 2013: the new frontier

Despite the frequency with which obstetrics providers manage labor, evidence has emerged in the past few years challenging our historical understanding of normal labor progress over time. We are also confronted with the dearth of evidence to guide the optimal management of labor. With these data, we are presented with both the challenge of changing practice at the bedside and the opportunity for new discovery to optimize labor and delivery outcomes. Given the sheer frequency of labor and delivery, changes that improve outcomes even by a small magnitude have the potential to dramatically impact labor-associated morbidity at the population level.

Medical and nonmedical factors influencing utilization of delayed pushing in the second stage

OBJECTIVE

To evaluate factors impacting selection to delayed pushing in the second stage of labor.

STUDY DESIGN

This case-control study was a secondary analysis of a large retrospective cohort study. Cases included women who delayed pushing for 60 minutes or more in the second stage of labor. Controls began pushing prior to 60 minutes from the time of diagnosis of complete dilation. Demographic, labor, and nonmedical factors were compared among cases and controls. Logistic regression modeling was used to identify factors independently associated with delayed pushing.

RESULTS

We identified 471 women who delayed pushing and 4819 controls. Nulliparity, maternal body mass index > 25, high fetal station at complete dilation, regional anesthesia use, and start of second stage during staffing shift change were independent factors associated with increased use of delayed pushing. On the other hand, black race and second-stage management during night shift were associated with lower odds of employing delayed pushing. Delayed pushing was more commonly employed in nulliparous women, but 38.9% of multiparous women also delayed pushing.

CONCLUSION

We identified multiple factors associated with use of delayed pushing. This study helps to define current patterns of second-stage labor management.