A systematic review and a meta-analysis on the incidence of obstetric anal sphincter injuries during vaginal delivery.

AIM: The incidence of obstetric anal sphincter injuries (OASIS) has increased in the past two decades despite improved awareness of the risk factors. This study aimed to define the incidence of OASIS in women with different features (instrumental delivery or other variables). METHODS: A systematic review was conducted on articles reporting the incidence of OASIS. This review aims to examine the association of instrumentation and OASIS by performing a formal systematic review of the published literature. Databases used for the research were MEDLINE, Embase, CINAHL and 'Maternity and infant care' databases. RESULTS: Two independent reviewers screened the selected articles. 2326 duplicates were removed from the total of 4907 articles. The remaining 2581 articles were screened for title and abstract. 1913 articles were excluded due to irrelevance. The remaining 300 were screened as full text. Primiparity associated with the use of forceps were the features associated with the highest incidence of OASIS in the selected articles (19.4%). OASIS in all women had an overall incidence of 3.8%. The incidence of OASIS in all women by geographical region was the highest (6.5%) in North America. CONCLUSIONS: There are various factors that impact on the incidence of OASIS and the combination of some of these, such as the use of forceps in primiparas, resulted in the highest incidence of OASIS. The lack of international consensus is limiting the improvements that can be done to reduce OASIS rates and improve best clinical practice.

Prophylactic manual rotation of occiput posterior and transverse positions to decrease operative delivery: the PROPOP randomized clinical trial.

BACKGROUND: Persistent occiput posterior and occiput transverse positions are the most common malpositions of the fetal head during labor and are associated with prolonged second stage of labor, cesarean deliveries, instrumental deliveries, severe perineal tears, postpartum hemorrhage, and chorioamnionitis. Manual rotation is one of several strategies described to deal with these malpositions. OBJECTIVE: This study aimed to determine if the trial of prophylactic manual rotation at the early second stage of labor is associated with a decrease in operative deliveries (instrumental and/or cesarean deliveries). STUDY DESIGN: We conducted a multicenter, open-label, randomized controlled trial in 4 French hospitals. Women with singleton term pregnancy and occiput posterior or occiput transverse position confirmed by ultrasound at the early second stage of labor and with epidural analgesia were eligible. Women were randomly assigned (1:1) to either undergo a trial of prophylactic manual rotation of occiput posterior or occiput transverse position (intervention group) or no trial of prophylactic manual rotation (standard group). The primary outcome was operative delivery (instrumental and/or cesarean deliveries). The secondary outcomes were length of the second stage of labor, maternal complications (postpartum hemorrhage, operative complications during cesarean delivery, episiotomy and perineal tears), and neonatal complications (Apgar score of <5 at 10 minutes, arterial umbilical pH of <7.10, neonatal injuries, neonatal intensive care unit admission). The main analysis was focused on intention-to-treat analysis. RESULTS: From December 2015 to December 2019, a total of 257 women (mean age, 30.4 years; mean gestational age, 40.1 weeks) were randomized: 126 were assigned to the intervention group and 131 were assigned to the standard group. Operative delivery was significantly less frequent in the intervention group compared with the standard group (29.4% [37 of 126] vs 41.2% [54 of 131]; P=.047; differential [intervention-standard] [95% confidence interval] = -11.8 [-15.7 to -7.9]; unadjusted odds ratio [95% confidence interval] = 0.593 [0.353-0.995]). Women in the intervention group were more likely to have a significantly shorter second stage of labor. CONCLUSION: Trial of prophylactic manual rotation of occiput posterior or occiput transverse positions during the early second stage of labor was statistically associated with a reduced risk of operative delivery. This maneuver could be a safe strategy to prevention operative delivery.

The impact of physical activity during pregnancy on labor and delivery.

BACKGROUND: Physical activity in pregnancy is associated with decreased risks of adverse pregnancy outcomes such as gestational diabetes and preeclampsia. However, the relationship between the amount and type of physical activity during pregnancy and subsequent labor outcomes remains unclear. OBJECTIVE: This study aimed to test the hypothesis that higher levels of physical activity across different lifestyle domains in pregnancy are associated with a shorter duration of labor. STUDY DESIGN: This study is a secondary analysis of a prospective cohort study in which patients with singleton pregnancies without a major fetal anomaly were administered the Kaiser Physical Activity Survey in each trimester. The Kaiser Physical Activity Survey was designed specifically to quantify various types of physical activities in women and includes 4 summative indices-housework/caregiving, active living habits, sports, and occupation. The study included women at full-term gestations admitted for induction of labor or spontaneous labor. The primary outcome of this analysis was duration of the second stage of labor. Secondary outcomes were duration of the active stage, prolonged first and second stage, mode of delivery, rates of second-stage cesarean delivery, operative vaginal delivery, severe perineal lacerations, and postpartum hemorrhage. These outcomes were compared between patients with and without high physical activity levels, defined as overall Kaiser Physical Activity Survey score ≥75th percentile in the third trimester. Multivariable logistic regression was used to adjust for obesity and epidural use. In addition, a subgroup analysis of nulliparous patients was performed. RESULTS: A total of 811 patients with complete Kaiser Physical Activity Survey data in the third trimester were included in this analysis. The median Kaiser Physical Activity Survey score was 9.5 (8.2-10.8). Of the 811 patients, 203 (25%) had higher levels of physical activity in pregnancy. There was no difference in the duration of the second stage of labor between patients with and without higher physical activity levels (1.29±2.94 vs 0.97±2.08 hours; P=.15). The duration of active labor was significantly shorter in patients with higher levels of physical activity (5.77±4.97 vs 7.43±6.29 hours; P=.01). Patients with higher physical activity levels were significantly less likely to have a prolonged first stage (9.8% vs 19.4%; P<.01; adjusted relative risk, 0.55; 95% confidence interval, 0.34-0.83). However, rates of prolonged second-stage cesarean delivery, operative vaginal deliveries, and perineal lacerations were similar between the 2 groups. CONCLUSION: Patients who are more physically active during pregnancy have a shorter duration of active labor.

Intrapartum sonographic assessment of the fetal head flexion in protracted active phase of labor and association with labor outcome: a multicenter, prospective study.

BACKGROUND: To date, no research has focused on the sonographic quantification of the degree of flexion of the fetal head in relation to the labor outcome in women with protracted active phase of labor. OBJECTIVE: This study aimed to assess the relationship between the transabdominal sonographic indices of fetal head flexion and the mode of delivery in women with protracted active phase of labor. STUDY DESIGN: Prospective evaluation of women with protracted active phase of labor recruited across 3 tertiary maternity units. Eligible cases were submitted to transabdominal ultrasound for the evaluation of the fetal head position and flexion, which was measured by means of the occiput-spine angle in fetuses in nonocciput posterior position and by means of the chin-to-chest angle in fetuses in occiput posterior position. The occiput-spine angle and the chin-to-chest angle were compared between women who had vaginal delivery and those who had cesarean delivery. Cases where obstetrical intervention was performed solely based on suspected fetal distress were excluded. RESULTS: A total of 129 women were included, of whom 43 (33.3%) had occiput posterior position. Spontaneous vaginal delivery, instrumental delivery, and cesarean delivery were recorded in 66 (51.2%), 17 (13.1%), and 46 (35.7%) cases, respectively. A wider occiput-spine angle was measured in women who had vaginal delivery compared with those submitted to cesarean delivery owing to labor dystocia (126±14 vs 115±24; P<.01). At the receiver operating characteristic curve, the area under the curve was 0.675 (95% confidence interval, 0.538-0.812; P<.01), and the optimal occiput-spine angle cutoff value discriminating between cases of vaginal delivery and those delivered by cesarean delivery was 109°. A narrower chin-to-chest angle was measured in cases who had vaginal delivery compared with those undergoing cesarean delivery (27±33 vs 56±28 degrees; P<.01). The area under the curve of the chin-to-chest angle in relation to the mode of delivery was 0.758 (95% confidence interval, 0.612-0.904; P<.01), and the optimal cutoff value discriminating between vaginal delivery and cesarean delivery was 33.0°. CONCLUSION: In women with protracted active phase of labor, the sonographic demonstration of fetal head deflexion in occiput posterior and in nonocciput posterior fetuses is associated with an increased incidence of cesarean delivery owing to labor dystocia. Such findings suggest that intrapartum ultrasound may contribute in the categorization of the etiology of labor dystocia.

Predicting obstetrical anal sphincter injuries in patients who undergo vaginal birth after cesarean delivery.

BACKGROUND: Women with a history of previous cesarean delivery must weigh the numerous potential risks and benefits of elective repeat cesarean delivery or trial of labor after cesarean delivery. Notably, 1 important risk of vaginal delivery is obstetrical anal sphincter injuries. Furthermore, the rate of obstetrical anal sphincter injuries is high among women undergoing vaginal birth after cesarean delivery. However, the risk of obstetrical anal sphincter injuries is not routinely included in the trial of labor after cesarean delivery counseling, and there is no tool available to risk stratify obstetrical anal sphincter injuries among women undergoing vaginal birth after cesarean delivery. OBJECTIVE: This study aimed to develop and validate a predictive model to estimate the risk of obstetrical anal sphincter injuries in the setting of vaginal birth after cesarean delivery population to improve antenatal counseling of patients regarding risks of trial of labor after cesarean delivery. STUDY DESIGN: This study was a secondary subgroup analysis of the Maternal-Fetal Medicine Units Network Trial of Labor After Cesarean Delivery prospective cohort (1999-2002). We identified women within the Maternal-Fetal Medicine Units Network cohort with 1 previous cesarean delivery followed by a term vaginal birth after cesarean delivery. This Maternal-Fetal Medicine Units Network Vaginal Birth After Cesarean Delivery cohort was stratified into 2 groups based on the presence of obstetrical anal sphincter injuries, and baseline characteristics were compared with bivariate analysis. Significant covariates in bivariate testing were included in a backward stepwise logistic regression model to identify independent risk factors for obstetrical anal sphincter injuries and generate a predictive model for obstetrical anal sphincter injuries in the setting of vaginal birth after cesarean delivery. Internal validation was performed using bootstrapped bias-corrected estimates of model concordance indices, Brier scores, Hosmer-Lemeshow chi-squared values, and calibration plots. External validation was performed using data from a single-site retrospective cohort of women with a singleton vaginal birth after cesarean delivery from January 2011 to December 2016. RESULTS: In this study, 10,697 women in the Maternal-Fetal Medicine Units Network Trial of Labor After Cesarean Delivery cohort met the inclusion criteria, and 669 women (6.3%) experienced obstetrical anal sphincter injuries. In the model, factors independently associated with obstetrical anal sphincter injuries included use of forceps (adjusted odds ratio, 5.08; 95% confidence interval, 4.10-6.31) and vacuum assistance (adjusted odds ratio, 2.64; 95% confidence interval, 2.02-3.44), along with increasing maternal age (adjusted odds ratio, 1.05; 95% confidence interval, 1.04-1.07 per year), body mass index (adjusted odds ratio, 0.99; 95% confidence interval, 0.97-1.00 per unit kg/m2), previous vaginal delivery (adjusted odds ratio, 0.19; 95% confidence interval, 0.15-0.23), and tobacco use during pregnancy (adjusted odds ratio, 0.59; 95% confidence interval, 0.43-0.82). Internal validation demonstrated appropriate discrimination (concordance index, 0.790; 95% confidence interval, 0.771-0.808) and calibration (Brier score, 0.047). External validation used data from 1266 women who delivered at a tertiary healthcare system, with appropriate model discrimination (concordance index, 0.791; 95% confidence interval, 0.735-0.846) and calibration (Brier score, 0.046). The model can be accessed at oasisriskscore.xyz. CONCLUSION: Our model provided a robust, validated estimate of the probability of obstetrical anal sphincter injuries during vaginal birth after cesarean delivery using known antenatal risk factors and 1 modifiable intrapartum risk factor and can be used to counsel patients regarding risks of trial of labor after cesarean delivery compared with risks of elective repeat cesarean delivery.

Factors and outcomes associated with the induction of labor in referral hospitals of Amhara regional state, Ethiopia: a multicenter study.

BACKGROUND: Induction of labor is an artificial initiation of uterine contractions after fetal viability with the aim of vaginal delivery prior to the onset of spontaneous labor. Prevalence of induction of labor is increasing worldwide with subsequent increase in failure rate. However, there is limited evidence on labor induction in Ethiopia. Therefore, this study was aimed at assessing the prevalence and associated factors of failed induction of labor among women undergoing induction of labor at referral hospitals of Amhara national regional state, Ethiopia, 2016. METHOD: A multicenter cross-sectional study was conducted at referral hospitals found in Amhara national regional state from February 01 to September 30, 2016. Multistage sampling technique was employed to select a total of 484 women who underwent labor induction. Pre-tested structured questionnaires and checklists were used to collect the data. Data were entered into EPI info version 7 and analyzed using SPSS version 20 software. Stepwise Binary Logistic regression model was fitted to identify factors associated with failed induction of labor. The level of significance was determined based on the adjusted odds ratio with 95% confidence interval at the p-value of ≤0.05. RESULT: The prevalence of failed induction of labor among women undergoing induction of labor was 31.4% (95% CI: 27.0, 36.0). Failed induction of labor was independently predicted by a Bishop score of ≤5 (AOR = 2.1; 95% CI: 1.3, 3.6), prolonged latent first stage of labor (AOR = 2.0; 95% CI: 1.2, 3.5), induction with oxytocin alone (AOR = 4.2; 95% CI: 2.2, 8.1), nulliparity (ARO = 1.9; 95% CI: 1.2, 2.9), post term pregnancy (AOR = 4.1; 95% CI: 1.8, 9.3) and hypertensive disorder of pregnancy (AOR = 2.4; 95% CI: 1.5, 5.1). CONCLUSION: Failed induction of labor was high in the study area compared to the reports of previous studies done in Ethiopia. The majority of the determinants of failed induction of labor were connected with unjustifiable and inconsistent indication of induction of labor. Thus, preparing standardized practical guidelines and preventing unjustifiable case selection may help reduce the current high failure rates.

Comparison of maternal and fetal outcomes between delayed and immediate pushing in the second stage of vaginal delivery: systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The second stage of labor begins with complete dilatation of the cervix until delivery of the fetus. After the cervix has fully dilated, the caregiver/nurse will provide guidance to the mother regarding the push technique for delivering the fetus (immediate pushing, IP). Because some women receive analgesic medications during labor, they might not be able to push correctly. Therefore, some obstetricians choose to postpone guiding the patient to push until the cervix is fully dilated and the fetal head has begun to descend. At this point, there is an involuntary exertion sensation (delayed pushing, DP) that saves energy and, at the same time, decreases tiredness and fatigue. The best timing for pushing during the second stage of labor is still controversial. The aim of this study was to investigate the different maternal and neonatal outcomes with IP and DP in the second stage of labor. METHODS: The Cochrane Library, EMBASE, PubMed, and Airiti Library (a Chinese database) were searched up to July 2019. Search keywords included: "labor stage, second", "delayed pushing", and "immediate pushing". Gray literature and bibliographies of articles were checked. No language restrictions were applied. Only randomized controlled trials were included. Two independent reviewers identified relevant studies and extracted data. The quality of the studies was assessed using the Cochrane's Risk of Bias tool. A random-effects meta-analysis was used to pool results. Mean differences and risk ratios were calculated with 95% confidence intervals (CIs) using Review Manager 5.3 (The Nordic Cochrane Centre, Copenhagen, Denmark, 2014). The risk of heterogeneity was reported as I2, and publication bias was visually assessed by funnel plots. RESULTS: In total, 15 studies (n = 6121 participants) were identified. Pooled results demonstrated the following. (1) As to maternal outcomes, in comparison, IP shortened the length of the second stage of labor by 40.9 (95% CI 23.6-58.2) min; however, DP decreased the total length of pushing by 25.4 (95% CI 13.9-37.0) min. The incidence of instrument-assisted vaginal delivery was significantly lower in the DP group in western countries (RR 0.85, 95% CI 0.74-0.97). In addition, the maternal postpartum fatigue score was 0.67 points lower in the DP group (95% CI - 1.09 to - 0.26). There was no statistical significance of the cesarean section rate or blood loss. (2) As to neonatal outcomes (Apgar score at 1 min), the DP group showed a higher score (by 0.19; 95% CI 0.10-0.27 points) than the IP group. CONCLUSIONS: Delayed pushing can decrease the total pushing time and decrease the fatigue score after delivery without significant adverse events compared to the early pushing group. Therefore, we recommend that caregivers instruct the pushing time at the optimal moment, which allows women to have more resting time and save energy during labor.

Prediction of vaginal birth after cesarean deliveries using machine learning.

BACKGROUND: Efforts to reduce cesarean delivery rates to 12-15% have been undertaken worldwide. Special focus has been directed towards parturients who undergo a trial of labor after cesarean delivery to reduce the burden of repeated cesarean deliveries. Complication rates are lowest when a vaginal birth is achieved and highest when an unplanned cesarean delivery is performed, which emphasizes the need to assess, in advance, the likelihood of a successful vaginal birth after cesarean delivery. Vaginal birth after cesarean delivery calculators have been developed in different populations; however, some limitations to their implementation into clinical practice have been described. Machine-learning methods enable investigation of large-scale datasets with input combinations that traditional statistical analysis tools have difficulty processing. OBJECTIVE: The aim of this study was to evaluate the feasibility of using machine-learning methods to predict a successful vaginal birth after cesarean delivery. STUDY DESIGN: The electronic medical records of singleton, term labors during a 12-year period in a tertiary referral center were analyzed. With the use of gradient boosting, models that incorporated multiple maternal and fetal features were created to predict successful vaginal birth in parturients who undergo a trial of labor after cesarean delivery. One model was created to provide a personalized risk score for vaginal birth after cesarean delivery with the use of features that are available as early as the first antenatal visit; a second model was created that reassesses this score after features are added that are available only in proximity to delivery. RESULTS: A cohort of 9888 parturients with 1 previous cesarean delivery was identified, of which 75.6% of parturients (n=7473) attempted a trial of labor, with a success rate of 88%. A machine-learning-based model to predict when vaginal delivery would be successful was developed. When features that are available at the first antenatal visit are used, the model showed a receiver operating characteristic curve with area under the curve of 0.745 (95% confidence interval, 0.728-0.762) that increased to 0.793 (95% confidence interval, 0.778-0.808) when features that are available in proximity to the delivery process were added. Additionally, for the later model, a risk stratification tool was built to allocate parturients into low-, medium-, and high-risk groups for failed trial of labor after cesarean delivery. The low- and medium-risk groups (42.4% and 25.6% of parturients, respectively) showed a success rate of 97.3% and 90.9%, respectively. The high-risk group (32.1%) had a vaginal delivery success rate of 73.3%. Application of the model to a cohort of parturients who elected a repeat cesarean delivery (n=2145) demonstrated that 31% of these parturients would have been allocated to the low- and medium-risk groups had a trial of labor been attempted. CONCLUSION: Trial of labor after cesarean delivery is safe for most parturients. Success rates are high, even in a population with high rates of trial of labor after cesarean delivery. Application of a machine-learning algorithm to assign a personalized risk score for a successful vaginal birth after cesarean delivery may help in decision-making and contribute to a reduction in cesarean delivery rates. Parturient allocation to risk groups may help delivery process management.

Prevalence of levator hiatal overdistension after vacuum and forceps deliveries.

INTRODUCTION: Levator ani avulsion rates after assisted vaginal delivery have been reported in the literature. However, there are no definitive data regarding the association between overdistention and assisted vaginal delivery. Therefore, our aim is to report overdistention rates after assisted vaginal delivery with a postpartum ultrasound examination. MATERIALS AND METHODS: This multicenter study involved a retrospective analysis of data from primiparous women (n = 602) who had previously been recruited at three tertiary hospitals between January 2015 and January 2017. Overdistention was assessed at 6 months postpartum using three-/four-dimensional transperineal ultrasound. Patients with levator ani muscle avulsion were excluded. Overdistention was defined as a levator hiatal area ≥ 25 cm2 on Valsalva. RESULTS: Of the 602 primiparous patients, 250 patients who satisfied the inclusion criteria (139 patients who underwent forceps delivery and 111 patients who underwent vacuum delivery) were evaluated. Overdistention occurred in 20% (50 of 250) of these patients. Overdistention was observed for 1% (1/111) of vacuum deliveries and 35.3% (49 of 139) of forceps deliveries. We found an increased risk of overdistention following forceps delivery compared to vacuum delivery, with a crude odds ratio (OR) of 59.9 (95% confidence interval [CI]: 8.1, 442.2) and an adjusted OR (adjusted for maternal age, second-stage duration, and head circumference) of 17.6 (95% CI: 2.3, 136.7). CONCLUSIONS: Postpartum overdistention occurred for 20% of assisted vaginal deliveries, with an increased risk of overdistention following forceps delivery compared to vacuum delivery.

Babies in occiput posterior position are significantly more likely to require an emergency cesarean birth compared with babies in occiput transverse position in the second stage of labor: A prospective observational study.

INTRODUCTION: Malposition complicates 2-13% of births at delivery, leading to increased obstetric interventions (cesarean section and instrumental delivery) and higher rates of adverse fetal and maternal outcomes. Limited data are available regarding the likely rates of obstetric intervention and subsequent neonatal and maternal outcomes of births with babies in persistent occiput posterior position vs those in persistent occiput transverse position. The UK Audit and Research trainee Collaborative in Obstetrics and Gynecology (UK-ARCOG) network set out to collect data prospectively at delivery on final mode of delivery and immediate outcomes. MATERIAL AND METHODS: The UK-ARCOG network collected data on all births with malposition of the fetal head complicating the second stage of labor (n = 838) (occiput posterior/occiput transverse) requiring rotational vaginal operative birth or emergency cesarean to expedite delivery across 66 participating UK National Health Service maternity units over a 1-month period. The outcomes considered were the need for emergency cesarean section without a trial of instrumental delivery, success of the first method of delivery employed in achieving a vaginal delivery and neonatal/maternal outcomes. RESULTS: Obstetricians regarded assistance with an operative vaginal delivery method to be unsafe in 15% of babies in occiput posterior position and 6.1% of babies in occiput transverse position, and they were delivered by primary emergency cesarean section. When vaginal delivery was deemed safe (defined as attempted assisted vaginal rotational delivery), the first instrument attempted was successful in 74.4% of occiput posterior babies and 79.3% of occiput transverse babies. CONCLUSIONS: Our data facilitates decision making by obstetricians to increase safety of assisted rotational operative delivery of a malpositioned baby at initial assessment and in counseling women. Until data from a well-designed randomized controlled trial of instrumental delivery vs emergency cesarean section are available, this manuscript provides contemporaneous national data from a high resource setting within a structured training program, to assist the selection of an appropriate instrument/method for the delivery of a malpositioned baby.

The impact of stage of labor on adverse maternal and neonatal outcomes in multiparous women: a retrospective cohort study.

BACKGROUND: The correlation between stage of labor and adverse delivery outcomes has been widely studied. Most of studies focused on nulliparous women, it was not very clear what impact the stage of labor duration had on multiparous women. METHODS: A retrospective cohort study was conducted among all the multiparous women of cephalic, term, singleton births, who planned vaginal delivery. The total stage of labor covered the first stage and the second stage in this study, and they were divided into subgroups. Adverse maternal outcomes were defined as referral cesarean delivery, instrumental delivery, postpartum hemorrhage, perineal laceration (III and IV degree), hospitalization stay ≥90th, and adverse neonatal outcomes as NICU, shoulder dystocia, Apgar score ≤ 7(5 min), neonatal resuscitation, assisted ventilation required immediately after delivery. RESULTS: There were 7109 parturients included in this study. The duration of first stage was 6.2(3.6-10.0) hours, the second stage was 0.3(0.2-0.7) hour, the total stage was 6.9(4.1-10.7) hours in multiparous women. At the first stage, the rates of overall adverse outcome were 21, 23.4, 28.8, 35.5, 38.4% in subgroups < 6 h, 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥24 h, which increased significantly (X2 = 57.64, P < 0.001), and ARR (95% CI) were 1.10 (0.92,1.31), 1.33 (1.04,1.70), 1.80 (1.21,2.68), 2.57 (1.60,4.15) compared with subgroup < 6 h (ARR = 1); At the second stage, the rates of overall adverse outcome were 20.0, 30.7, 38.5, 61.2, 69.6% in subgroups < 1 h, 1-1.9 h, 2-2.9 h, 3-3.9 h, ≥4 h (X2 = 349.70, P < 0.001), and ARR (95% CI) were 1.89 (1.50, 2.39), 2.22 (1.55, 3.18), 10.64 (6.09, 18.59), 11.75 (6.55, 21.08) compared with subgroup < 1 h (ARR = 1)). At the total stage, the rates of overall adverse outcome were 21.5, 30.8, 42.4% in subgroups < 12 h, 12-23.9 h, ≥24 h (X2 = 84.90, P < 0.001), and ARR (95% CI) were 1.41 (1.16,1.72), 3.17 (2.10,4.80) compared with subgroup < 12 h (ARR = 1). CONCLUSIONS: The prolonged stage of labor may lead to increased adverse outcomes in multiparous women, it was an independent risk factor of adverse maternal and neonatal outcomes.

Intrapartum and neonatal mortality in low-risk term women in midwife-led care and obstetrician-led care at the onset of labor: A national matched cohort study.

INTRODUCTION: Midwife-led models of care have been the subject of debate for many years. We conducted a study to compare intrapartum and neonatal mortality rates in midwife-led (primary) vs obstetrician-led (secondary) care at the onset of labor in low-risk term women. MATERIAL AND METHODS: We performed an unmatched and a propensity score matched cohort study using data from the national perinatal audit registry (PAN) and from the national perinatal registry (PERINED) of the Netherlands. We included women with singleton pregnancies (without congenital anomalies or antepartum fetal death) who gave birth at term between 2010 and 2012. We excluded the following major risk factors: non-vertex position of the fetus, previous cesarean birth, hypertension, diabetes mellitus, prolonged rupture of membranes (≥24 hours), vaginal bleeding in the second half of pregnancy, nonspontaneous start of labor and post-term pregnancy (≥42 weeks). The primary outcome was intrapartum or neonatal mortality up to 28 days after birth. Secondary outcome measures were mode of delivery and a 5-minute Apgar score <7. RESULTS: We included 259 211 women. There were 100/206 642 (0.48‰) intrapartum and neonatal deaths in the midwife group and 23/52 569 (0.44‰) in the obstetrician group (odds ratio [OR] 1.11, 95% CI 0.70-1.74). Propensity score matched analysis showed mortality rates of 0.49‰ (26/52 569) among women in midwife-led care and 0.44‰ (23/52 569) for women in obstetrician-led care (OR 1.13, 95% CI 0.65-1.98). In the midwife group there were significantly lower rates of vaginal instrumental deliveries (8.4% vs 13.0%; matched OR 0.65, 95% CI 0.62-0.67) and intrapartum cesarean sections (2.6% vs 8.2%; matched OR 0.32, 95% CI 0.30-0.34), and fewer neonates with low Apgar scores (<7 after 5 minutes) (0.69% vs 1.11%; matched OR 0.61, 95% CI 0.53-0.69). CONCLUSIONS: Among low-risk term women, there were comparable intrapartum and neonatal mortality rates for women starting labor in midwife-led vs obstetrician-led care, with lower intervention rates and fewer low Apgar scores in the midwife group.

Evaluation of Suzor forceps training by studying obstetric anal sphincter injuries: a retrospective study.

BACKGROUND: Instrumental deliveries are an unavoidable part of obstetric practice. Dedicated training is needed for each instrument. To identify when a trainee resident can be entrusted with instrumental deliveries by Suzor forceps by studying obstetric anal sphincter injuries. METHODS: A French retrospective observational study of obstetric anal sphincter injuries due to Suzor forceps deliveries performed by trainee residents was conducted from November 2008 to November 2016 at Limoges University Hospital. Perineal lesion risk factors were studied. Sequential use of a vacuum extractor and then forceps was also analyzed. RESULTS: Twenty-one residents performed 1530 instrumental deliveries, which included 1164 (76.1%) using forceps and 89 (5.8%) with sequential use of a vacuum extractor and then forceps. Third and fourth degree perineal tears were diagnosed in 82 patients (6.5%). Residents caused fewer obstetric anal sphincter injuries after 23.82 (+/- 0.8) deliveries by forceps (p = 0.0041), or after 2.36 (+/- 0.7) semesters of obstetrical experience (p = 0.0007). No obese patient (body mass index> 30) presented obstetric anal sphincter injuries (p = 0.0013). There were significantly fewer obstetric anal sphincter injuries after performance of episiotomy (p <  0.0001), and more lesions in the case of the occipito-sacral position (p = 0.028). Analysis of sequential instrumentation did not find any additional associated risk. CONCLUSION: Training in the use of Suzor forceps requires extended mentoring in order to reduce obstetric anal sphincter injuries. A stable level of competence was found after the execution of at least 24 forceps deliveries or after 3 semesters (18 months) of obstetrical experience.

Differential effects of different delivery methods on progression to severe postpartum hemorrhage between Chinese nulliparous and multiparous women: a retrospective cohort study.

BACKGROUND: Delivery methods are associated with postpartum hemorrhage (PPH) both in nulliparous and multiparous women. However, few studies have examined the difference in this association between nulliparous and multiparous women. This study aimed to explore the difference of maternal and neonatal characteristics and delivery methods between Chinese nulliparous and multiparous women, and then examine the differential effects of different delivery methods on PPH between these two-type women. METHODS: Totally 151,333 medical records of women who gave birth between April 2013 to May 2016 were obtained from the electronic health records (EHR) in a northern province, China. The severity of PPH was estimated and classified into blood loss at the level of < 900 ml, 900-1500 ml, 1500-2100 ml, and > 2100 ml. Neonatal and maternal characteristics related to PPH were derived from the same database. Multiple ordinal logistic regression was used to estimate associations. RESULTS: Medical comorbidities, placenta previa and accreta were higher in the nulliparous group and the episiotomy rate was higher in the multiparous group. Compared with spontaneous vaginal delivery (SVD), the adjusted odds (aOR) for progression to severe PPH due to the forceps-assisted delivery was much higher in multiparous women (aOR: 9.32; 95% CI: 3.66-23.71) than in nulliparous women (aOR: 1.70; 95% CI: 0.91-3.18). The (aOR) for progression to severe PPH due to cesarean section (CS) compared to SVD was twice as high in the multiparous women (aOR: 4.32; 95% CI: 3.03-6.14) as in the nulliparous women (aOR: 2.04; 95% CI: 1.40-2.97). However, the (aOR) for progression to severe PPH due to episiotomy compared to SVD between multiparous (aOR: 1.24; 95% CI: 0.96-1.62) and nulliparous women (aOR: 1.55; 95% CI: 0.92-2.60) was not significantly different. The (aOR) for progression to severe PPH due to vacuum-assisted delivery compared to SVD in multiparous women (aOR: 2.41; 95% CI: 0.36-16.29) was not significantly different from the nulliparous women (aOR: 1.05; 95% CI: 0.40-2.73). CONCLUSIONS: Forceps-assisted delivery and CS methods were found to increase the risk of severity of the PPH. The adverse effects were even greater for multiparous women. Episiotomy and the vacuum-assisted delivery, and SVD were similar to the risk of progression to severe PPH in either nulliparous or multiparous women. Our findings have implications for the obstetric decision on the choice of delivery methods, maternal and neonatal health care, and obstetric quality control.

Rationale and design of ePPOP-ID: a multicenter randomized controlled trial using an electronic-personalized program for obesity in pregnancy to improve delivery.

BACKGROUND: Pre-pregnancy obesity and excessive gestational weight gain (GWG) are established risk factors for adverse pregnancy, delivery and birth outcomes. Pregnancy is an ideal moment for nutritional interventions in order to establish healthier lifestyle behaviors in women at high risk of obstetric and neonatal complications. METHODS: Electronic-Personalized Program for Obesity during Pregnancy to Improve Delivery (ePPOP-ID) is an open multicenter randomized controlled trial which will assess the efficacy of an e-health web-based platform offering a personalized lifestyle program to obese pregnant women in order to reduce the rate of labor procedures and delivery interventions in comparison to standard care. A total of 860 eligible pregnant women will be recruited in 18 centers in France between 12 and 22 weeks of gestation, randomized into the intervention or the control arm and followed until 10 weeks of postpartum. The intervention is based on nutrition, eating behavior, physical activity, motivation and well-being advices in which personalization is central, as well as the use of a mobile/tablet application. Inputs includes data from the medical record of participants (medical history, anthropometric data), from the web platform (questionnaires on dietary habits, eating behavior, physical activity and motivation in both groups), and adherence to the program (time of connection for the intervention group only). Data are collected at inclusion, 32 weeks, delivery and 10 weeks postpartum. As primary outcome, we will use a composite endpoint score of obstetrical interventions during labor and delivery, defined as caesarean section and instrumental delivery (forceps and vacuum extractor). Secondary outcomes will consist of data routinely collected as part of usual antenatal and perinatal care, such as GWG, hypertension, preeclampsia, as well as fetal and neonatal outcomes including premature birth, gestational age at birth, birth weight, macrosomia, Apgar score, arterial umbilical cord pH, neonatal traumatism, hyperbilirubinemia, respiratory distress syndrome, transfer in neonatal intensive care unit, and neonatal adiposity. Post-natal outcomes will be duration of breastfeeding, maternal weight retention and child weight at postnatal visit. DISCUSSION: The findings of the ePPOP-ID trial will help design e-health intervention program for obese women in pregnancy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02924636 / October 5th 2016.

Risk of preterm birth in the subsequent pregnancy following caesarean section at full cervical dilatation compared with mid-cavity instrumental delivery.

BACKGROUND: Expediting delivery in the second stage of labour often involves a choice between a caesarean section at full dilatation or mid-cavity instrumental delivery. Accumulating evidence suggests that the mode of delivery may influence the risk of preterm birth in the subsequent pregnancy. AIMS: To directly compare first birth caesarean section at full dilatation with mid-cavity instrumental delivery for the risk of preterm birth in the subsequent pregnancy (second birth). A further aim was to identify predictive factors associated with these index modes of delivery. MATERIALS AND METHODS: This is a retrospective cohort study involving three maternity hospitals in western Sydney over the period of 2006-2017. Inclusion criteria were nulliparous women with a singleton term cephalic first birth delivered by caesarean section at full dilatation or mid-cavity instrumental delivery, and whose second birth also occurred under our care. Data were analysed separately for first and second births. RESULTS: There were 425 caesarean section at full dilatation and 874 mid-cavity instrumental cases which met inclusion criteria. The risk of preterm birth in the second birth was 5.7% compared to 3.2%, respectively (risk ratio 1.76; 95% CI 1.04-3.00; P = 0.035). After excluding causes of preterm birth not related to previous mode of delivery, the risk of spontaneous preterm birth was 4.3% compared to 2.0%, respectively (risk ratio 2.18; 1.14-4.19; P = 0.019). CONCLUSION: Caesarean section at full dilatation is associated with a significantly higher rate of preterm birth in the subsequent pregnancy compared to a mid-cavity instrumental delivery. This should be considered in second-stage mid-cavity decision-making.

Significant reduction in umbilical artery metabolic acidosis after implementation of intrapartum ST waveform analysis of the fetal electrocardiogram.

BACKGROUND: Although the evidence regarding the benefit of using ST waveform analysis of the fetal electrocardiogram is conflicting, ST waveform analysis is considered as adjunct to identify fetuses at risk for asphyxia in our center. Most randomized controlled trials and meta-analyses have not shown a significant decrease in umbilical metabolic acidosis, while some observational studies have shown a gradual decrease of this outcome over a longer period of time. Observational studies can give more insight into the effect of implementation of the ST technology in daily clinical practice. OBJECTIVE: To evaluate the change in frequency of perinatal intervention and adverse neonatal outcome after the implementation of ST waveform analysis of the fetal electrocardiogram from 2000 to 2013. STUDY DESIGN: This retrospective longitudinal study was conducted in a tertiary referral center. A total of 19,664 medium- and high-risk singleton pregnancies with fetuses in cephalic presentation, a gestational age of ≥36 weeks, and the intention to deliver vaginally were included. ST waveform analysis of the fetal electrocardiogram was implemented in the year 2000 and by 2010 all deliveries were monitored using this technology. Data were collected on the following perinatal outcomes: fetal blood sampling, mode of delivery, umbilical cord blood gases, Apgar scores, neonatal encephalopathy, and perinatal death. Longitudinal trend analysis was used to detect changes over time in all deliveries monitored by cardiotocography either alone or in adjunct to ST waveform analysis of the fetal electrocardiogram. Logistic regression was used to correct for possible confounders. RESULTS: The umbilical artery metabolic acidosis rate declined from 2.5% (average rate of 2000 + 2001 + 2002) to 0.4% (average of 2011 + 2012 + 2013) (P < .001), which represents an 84% decrease. This decrease largely occurred between 2006 and 2008, during the Dutch randomized trial on fetal electrocardiogram ST waveform analysis. At this time, approximately 20% of deliveries were monitored using this method. Furthermore, there were significant reductions in fetal blood sampling rate (P < .001). Overall cesarean and vaginal instrumental deliveries decreased significantly (P < .001), but not for fetal distress. There were no changes in the Apgar scores. The incidence of neonatal encephalopathy was significantly lower in the second part of the study (odds ratio 0.39, 95% confidence interval 0.17-0.89). CONCLUSION: There was an 84% decrease in the incidence of umbilical artery metabolic acidosis in all deliveries between 2000 and 2013. The neonatal encephalopathy rate, fetal blood sampling rate, and the total number of cesarean and vaginal instrumental deliveries also decreased.

Pelvic organ prolapse as a function of levator ani avulsion, hiatus size, and strength.

BACKGROUND: Obstetrical levator ani muscle avulsion is detected after 10%-30% of vaginal deliveries and is associated with pelvic organ prolapse later in life. However, the mechanism by which levator avulsion may contribute to prolapse is unknown. OBJECTIVES: This study investigated the extent by which size of the levator hiatus and pelvic muscle weakness may explain the association between levator avulsion and pelvic organ prolapse. STUDY DESIGN: This was a supplementary study of a longitudinal cohort of parous women enrolled 5-10 years after first delivery and assessed annually for prolapse (defined as descent beyond the hymen) for up to 9 annual visits. For this substudy, vaginally parous participants were assessed for levator avulsion using 3-dimensional transperineal ultrasound. Ultrasound was performed at a median interval of 11 years from delivery. Ultrasound volumes also were used to measure levator hiatus area with Valsalva. Pelvic muscle strength was measured with perineometry. Women with and without pelvic organ prolapse were compared for levator avulsion, levator hiatus area, and pelvic muscle strength, using multivariable logistic regression yielding a measure of mediation. Bootstrap methods were used to calculate the confidence interval corresponding to the measure of mediation by hiatus area and pelvic muscle strength. RESULTS: Prolapse was identified in 109 of 429 (25%) and was significantly associated with levator avulsion (odds ratio, 4.17; 95% confidence interval, 2.28-7.31). Prolapse also was associated with levator hiatus area (odds ratio, 1.52 per 5 cm2; 95% confidence interval, 1.34-1.73) and inversely with muscle strength (odds ratio, 0.87 per 5 cm H2O; 95% confidence interval, 0.81-0.94). In a multivariable logistic model including levator avulsion, levator hiatus area, and strength, the association between levator avulsion and prolapse was substantially attenuated and indeed was no longer statistically significant (odds ratio, 1.75; 95% confidence interval, 0.91-3.39). Hiatus area and strength mediated 61% (95% confidence interval, 34%-106%) of the association between avulsion and prolapse. Furthermore, since the 95% confidence interval for this estimate contained 100%, it cannot be ruled out that the 2 markers fully mediate the effect of avulsion on prolapse. CONCLUSIONS: The strong association between pelvic organ prolapse and levator avulsion can be explained to a large extent by a larger levator hiatus and weaker pelvic muscles after levator avulsion.

Single prior caesarean section and risk of anal sphincter injury.

INTRODUCTION AND HYPOTHESIS: Injury to the anal sphincter at vaginal delivery remains the leading cause of faecal incontinence in women. Previous studies reported an increased incidence of obstetric anal sphincter injury (OASI) in women attempting vaginal birth after caesarean section (VBAC). The aim of the paper was to establish whether women in their second pregnancy, with one previous uterine scar, are at a higher risk of OASI compared with nulliparous women. METHODS: All primiparous and secundiparous women with a previous caesarean section who delivered from 2008 to 2017 were analysed in a single-centre retrospective study. The primary endpoint was OASI. Labour characteristics in both groups were compared, and a multiple regression model was created. RESULTS: There were 8573 vaginal deliveries of nulliparous women and 3453 deliveries of women in their second pregnancy with a previous caesarean section, of whom 550 had a successful VBAC. There was no significant difference in the rate of OASI between primiparous women and those who had a successful VBAC: 3.5% (297/8573) versus 3.1% (17/550), P = 0.730). Foetal macrosomia (>4 kg) and forceps delivery were risk factors for sphincter injury, while episiotomy and epidural anaesthesia were protective. CONCLUSIONS: VBAC does not confer an increased risk of OASI after a first delivery by caesarean section when compared with nulliparous women. The rate of successful VBAC may be contributory and suggests that the risk conferred by VBAC may be unit-specific. Unit and national-level audit is necessary to investigate this risk further.

Prospective comparison of obstetric anal sphincter injury incidence between an Asian and Western hospital.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injury (OASIS) rates are reported to be higher in Asian women living in Western countries than in those living in Asia, but the reasons for the differences remain unclear. The objectives of this study were for a single examiner to prospectively compare OASIS rates in primiparous Asian women in an Asian and Western birth unit and determine potential birth factors that may influence the possible difference in OASIS incidence. METHODS: This was a prospective observational study based in Hong Kong, China, and Sydney, Australia, involving primiparous women > 36 weeks gestation of Asian descent undergoing vaginal delivery. A single examiner recorded basic patient demographics, observed all the deliveries at both sites, noting birthing techniques, and then examined the women, including a rectal examination, to determine OASIS incidence. RESULTS: Seventy births in Hong Kong and 66 in Sydney were studied. The incidence of OASIS was 34% in Sydney and 10% in Hong Kong (p = 0.001). Birthweight, epidural rate, body mass index, and instrumental delivery were higher in Sydney. Episiotomy rates were higher in Hong Kong (59.2% vs. 82.9%; p = 0.007). When comparing OASIS with no-OASIS, perineal length (OR = 0.36, 95% CI 0.17 to 0.76, p = 0.004) and birthweight (OR = 1.14, 95% CI 1.00 to 1.30, p = 0.039) were independent risk factors for OASIS. CONCLUSIONS: The incidence of OASIS in Asian women is significantly higher in a Western than in an Asian setting. In Asian women, perineal length and birthweight can affect the risk of OASIS at the time of vaginal delivery.