Persistent Occiput Posterior Position Research Articles

The association between unintended hysterotomy extensions with cesarean delivery and subsequent preterm birth

BackgroundAn increased risk of preterm birth has been observed among individuals with a previous second stage cesarean delivery compared with a previous vaginal delivery. One mechanism that may contribute to the increased risk of preterm birth following second stage cesarean delivery is the increased risk of cervical injury due to extension of the uterine incision (hysterotomy) into the cervix. Investigating the contribution of hysterotomy extension to the rate of preterm birth has not been well-studied and may shed light on the mechanisms underlying the observed relationship between mode of delivery and subsequent preterm birth. ObjectiveWe aimed to quantify the association between unintended hysterotomy extension and preterm birth in a subsequent delivery. Study designWe performed a retrospective cohort study using electronic perinatal data collected in two university-affiliated obstetrical centers. The study included patients with a primary cesarean delivery of a term, singleton live birth and a subsequent singleton birth in the same catchment (2005-2021). The primary outcome was subsequent preterm birth <37 weeks; secondary outcomes included subsequent preterm birth <34, <32 and <28 weeks. We assessed crude and adjusted associations between unintended hysterotomy extensions and subsequent preterm birth with log binomial regression models using rate ratios (RRs) and 95% confidence intervals (CIs). Adjusted models included several characteristics of the primary cesarean delivery such as maternal age, length of active labour, indication for cesarean delivery, chorioamnionitis, and maternal comorbidity. ResultsA total 4,797 patients met the study inclusion criteria. The overall rate of unintended hysterotomy extension in the primary cesarean delivery was 6.0% and the total rate of preterm birth in the subsequent pregnancy was 4.8%. Patients with an unintended hysterotomy extension were more likely to have a longer duration of active labour, chorioamnionitis, failed vacuum delivery attempt, second stage cesarean delivery, and persistent occiput posterior position of the fetal head in the primary cesarean delivery and higher rates of smoking in the subsequent pregnancy. Multivariable analyses controlling for several confounders showed that a history of hysterotomy extension is not associated with a higher risk of preterm birth <37 weeks gestation (adjusted RR 1.55, 95% CI 0.98-2.47), but is associated with preterm birth <34 weeks gestation (adjusted RR 2.49, 95% CI 1.06-5.42). ConclusionPatients with a uterine incision extension have a 2.5 times higher rate of preterm birth <34 weeks compared with patients who do not sustain this injury. This association was not observed for preterm birth <37 weeks. Future research should aim to replicate our analyses while incorporating additional data to minimize the potential for residual confounding.

Perinatal outcomes in persistent occiput posterior fetal position: a systematic review and meta-analysis

Background/Aims Persistent occiput posterior fetal position is the most common fetal malposition during labour. The aim of this study was to measure the magnitude of the effects of this labour dystocia on perinatal outcomes, as compared to anterior position. Methods A systematic review of the literature included prospective and retrospective cohort studies of singleton term pregnancies, comparing the effect of occiput posterior fetal position with occiput anterior fetal position. Random-effect meta-analysis was performed. Results Overall, eight studies were included, for a total of 140 590 participants. Women with fetuses in occiput posterior position were more likely to give birth via caesarean section (odds ratio: 6.74, P&lt;0.001), based on data from all eight studies. Newborns experienced an increased risk of admission to a neonatal intensive care unit (odds ratio: 1.60, P&lt;0.001), based on data from five of the included studies. Conclusions Persistent occiput posterior fetal position negatively affects maternal and neonatal outcomes. Future studies should reduce potential bias, include adjusted analysis and investigate the best clinical management for this labour dystocia.

Prevention of obstetric anal sphincter injuries with perineal support and lateral episiotomy: A historical cohort study.

There are many risk factors for obstetric anal sphincter injury (OASIS) and the interaction between these risk factors is complex and understudied. The many observational studies that have shown a reduction of OASIS rates after implementation of perineal support have short follow-up time. We aimed to study the effect of integration of active perineal support and lateral episiotomy on OASIS rates over a 15-year period and to study interactions between risk factors known before delivery. We performed a historical cohort study over the periods 1999-2006 and 2007-2021 at Stavanger University Hospital, Norway. The main outcome was OASIS rates. Women without a previous cesarean section and a live singleton fetus in cephalic presentation at term were eligible. The department implemented in 2007 the Finnish concept of active perineal protection, which includes support of perineum, control of fetal expulsion, good communication with the mother and observation of perineal stretching. The practice of mediolateral episiotomy was replaced with lateral episiotomy when indicated. We analyzed the OASIS rates in groups with and without episiotomy stratified for delivery mode, fetal position at delivery and for parity, and adjusted for possible confounders (maternal age, gestational age, oxytocin augmentation and epidural analgesia). We observed a long-lasting reduction in OASIS rates from 4.9% to 1.9% and an increase in episiotomy rates from 14.4% to 21.8%. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with instrumental vaginal deliveries and occiput anterior (OA) position; 3.4% vs 10.1% (OR 0.31; 95% CI: 0.24-0.40) and 6.1 vs 13.9% (OR 0.40; 95% CI: 0.19-0.82) in women with occiput posterior (OP) position. Lateral episiotomy was also associated with lower OASIS rates in nulliparous women with spontaneous deliveries and OA position; 2.1% vs 3.2% (OR 0.62; 95% CI: 0.49-0.80). The possible confounders had little confounding effects on the risk of OASIS in groups with and without episiotomy. We observed a long-lasting reduction in OASIS rates after implementation of preventive procedures. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with an instrumental delivery. Special attention should be paid to deliveries with persistent OP position.

Knowledge and experience of midwives and gynecologists about manual rotation of persistent occiput posterior position

Backgroundmanagement of persistent occiput posterior position has always been controversial. Manual rotation by a delivery operator can reduce instrumental delivery and cesarean section.AimThis study aims to determine the knowledge and experience of midwives and gynecologists about manual rotation of persistent occiput posterior position.MethodsThis descriptive cross-sectional study was performed in 2022. The questionnaire link was sent to 300 participating midwives and gynecologists via WhatsApp Messenger. Two hundred sixty-two participants completed the questionnaire. Data analysis was performed using SPSS22 statistical software and descriptive statistics.Results189 people (73.3%) had limited information about this technique, and 240 (93%) had never performed it. If this technique is recognized as a safe intervention and is included in the national protocol, 239 people (92.6%) want to learn, and 212 (82.2%) are willing to do it.ConclusionAccording to the results, the knowledge and skills of midwives and gynecologists need to be trained and improved for manual rotation of persistent occiput posterior position.

Persistent occiput posterior position: predictive factors of spontaneous rotation of the fetal head

Objectives To assess factors associated with spontaneous rotation in the occiput anterior position for fetuses in persistent occiput posterior (OP) during the second stage of labor. To evaluate maternal and fetal outcomes after spontaneous rotation of persistent OP. Methods This is a prospective cohort of 495 women with fetuses in persistent OP position, confirmed with ultrasonography during the second stage of labor. We performed simple logistic regressions, followed by multiple logistic regressions. Results Among 495 women with fetuses in persistent OP position, 78 fetuses (16%) underwent a spontaneous rotation during the second stage of labor. The multivariate analysis found that a short duration of the first stage of labor (<7 h) was associated with a spontaneous rotation of the fetal head in the second stage of labor (OR 0.43 [0.23; 0.76. There were fewer episiotomies (25.6% vs 52.3%, p < .01), cesarean sections (0% v. 5.4%, p = .03), and instrumental deliveries (8.9% vs. 50%, p < .01) in the "spontaneous rotation” group, and the two groups were similar regarding post-partum hemorrhage. The newborns in the “spontaneous rotation” group had a higher Apgar score at 1 min (10 v. 9, p = .02). The two groups did not differ for other neonatal parameters, such as arterial pH value, Apgar score at 5 min, birth trauma, or transfer into the pediatric unit. Conclusion A shorter duration of the first stage of labor (< 7 h) is a predictive factor of spontaneous rotation in the occiput anterior position for fetuses in persistent OP position. A spontaneous rotation in case of an OP position is associated with better maternal and fetal outcomes.

Prolonged Dystocic Labor in Neuraxial Analgesia and the Role of Enkephalin Neurotransmitters: An Experimental Study

The investigation studied the enkephalinergic neuro fibers (En) contained in the Lower Uterine Segment (LUS) during the prolonged dystocic labor (PDL) with Labor Neuraxial Analgesia (LNA). PDL is generally caused by fetal head malpositions in the Occiput Posterior Position (OPP), Persistent Occiput Posterior Position (POPP), in a transverse position (OTP), and asynclitism (A), and it is detected by Intrapartum Ultrasonography (IU). The En were detected in the LUS samples picked up during cesarean section (CS) of 38 patients undergoing urgent CS in PDL, compared to 37 patients submitted to elective CS. Results were statistically evaluated to understand the differences in En morphological analysis by scanning electron microscopy (SEM) and by fluorescence microscopy (FM). The LUS samples analysis showed an important reduction in En in LUS of CS for the PDL group, in comparison with the elective CS group. The LUS overdistension, by fetal head malpositions (OPP, OTP, A) and malrotations, lead to dystocia, modification of vascularization, and En reduction. The En reduction in PDL suggests that drugs used during the LNA, usually local anesthetics and opioids, cannot control the "dystocic pain", that differs from normal labor pain. The IU administration in labor and the consequent diagnosis of dystocia suggest stopping the numerous and ineffective top-up drug administration during LNA, and to shift the labor to operative vaginal delivery or CS.

Safety of vaginal delivery in women with placental chorioangiomas diagnosed by prenatal ultrasound: A retrospective cohort study.

This study aimed to examine the maternal and neonatal outcomes in different mode of delivery in pregnant women with placental chorioangiomas, in order to determine the safety of vaginal delivery.We conducted a retrospective study of 54 women with placental chorioangioma diagnosed by prenatal ultrasound and subsequently proven histologically, excluding those who underwent cesarean section for obstetric indications. The mode of delivery was divided into a vaginal delivery group (23 women) and a cesarean section group (31 women). The indication of cesarean section group was only for placental chorioangioma, no other obstetric indications. The maternal characteristics, pregnancy outcomes and the color doppler imaging characteristics of placental chorioangioma of the 2 groups were compared, and the clinical characteristics of women in the vaginal delivery group were described in detail.The incidence of placental chorioangioma was nearly 0.43‰ in our study. There was no significant difference in the maternal characteristics and pregnancy outcomes between the 2 groups. 82.6% (19/23) of the women successfully delivered vaginally and 4 failed who turned to cesarean section in the vaginal delivery group; among them, 17 women had giant chorioangiomas (>4 cm in diameter). The direct cause of vaginal delivery failure was fetal distress, persistent occiput posterior fetal position and cephalopelvic disproportion.Pregnant women with placental chorioangiomas and no other obstetric indications for cesarean section may attempt a vaginal delivery, even with giant chorioangiomas. If there are risk factors of vaginal delivery failure, the progress of labor needs to be closely monitored.

A biomechanical study of the birth position: a natural struggle between mother and fetus.

Birth trauma affects millions of women and infants worldwide. Levator ani muscle avulsions can be responsible for long-term morbidity, associated with 13-36% of women who deliver vaginally. Pelvic floor injuries are enhanced by fetal malposition, namely persistent occipito-posterior (OP) position, estimated to affect 1.8-12.9% of pregnancies. Neonates delivered in persistent OP position are associated with an increased risk for adverse outcomes. The main goal of this work was to evaluate the impact of distinct fetal positions on both mother and fetus. Therefore, a finite element model of the fetal head and maternal structures was used to perform childbirth simulations with the fetus in the occipito-anterior (OA) and OP position of the vertex presentation, considering a flexible-sacrum maternal position. Results demonstrated that the pelvic floor muscles' stretch was similar in both cases. The maximum principal stresses were higher for the OP position, and the coccyx rotation reached maximums of 2.17[Formula: see text] and 0.98[Formula: see text] for the OP and OA positions, respectively. Concerning the fetal head, results showed noteworthy differences in the variation of diameters between the two positions. The molding index is higher for the OA position, with a maximum of 1.87. The main conclusions indicate that an OP position can be more harmful to the pelvic floor and pelvic bones from a biomechanical point of view. On the other side, an OP position can be favorable to the fetus since fewer deformations were verified. This study demonstrates the importance of biomechanical analyses to further understand the mechanics of labor.

Management of persistent occiput posterior position: The added value of manual rotation.

To evaluate the delivery rate in the occiput posterior position according to the result of manual rotation performed in the case of persistent occiput posterior position. Secondary objectives were perinatal outcomes. This was a prospective cohort study conducted in two French tertiary care units. All women with a singleton pregnancy after 37weeks of gestation with a fetus in persistent occiput posterior position and an attempt of manual rotation were included. The main outcome was the occiput position at delivery. The secondary outcomes were duration of labor, mode of delivery, and perineal tears. Two groups were compared according to the result of manual rotation. In total, 460 women were included, with a manual rotation success of 62.4%. The success was significantly associated with a decrease in occiput posterior position at vaginal delivery (1.4% vs 57.2%, P<0.0001), cesarean (0.7% vs 17.9%, P<0.0001), operative vaginal delivery (40.1% vs 78%, P<0.0001), episiotomy (40.1% vs 54.9%, P<0.0001), and obstetric anal sphincter injury (3.1% vs 8.7%, P=0.008) compared with a failure. An attempt of manual rotation in the case of persistent occiput posterior position is associated with decreased rates of occiput posterior position at delivery, operative delivery, and anal sphincter injuries.

Prolongation of active second stage of labor: Associated factors and perinatal outcomes

BackgroundCurrent data does not allow to define a reasonable threshold of duration of active second stage (ASS) of labor beyond which a medical intervention should be considered. Primary objective was to analyse perinatal outcomes associated with prolonged ASS beyond 45 min. Secondarily, we analysed associated maternal, gestational, labor and delivery characteristics associated with prolonged ASS. MethodsWe performed a monocentric retrospective study among women with vaginal delivery, a term singleton cephalic fetus, without history of cesarean section. We compared women with active second stage of labor longer than 45 min (ASS ≥45 min, group A) and women with instrumental vaginal delivery (IVD) only for failure to progress (FtP) before 45 min of pushing (group B). Primary outcome was postpartum hemorrhage (PPH). Maternal and neonatal outcomes associated with ASS ≥ 45 min were assessed with multivariable logistic regression models. ResultsProlonged ASS ≥45 min (group A, N=177) was associated with lower rate of persistent occiput posterior position (1.7 vs 9.5%, p<0.01) and of non-engaged presentation when expulsive efforts started (10.7 vs 27.4%, p<0.01), compared to IVD for FtP <45 min (group B, N=84). In group A, 52% of women had instrumental delivery. Prolonged active second stage was independently associated with lower odds of episiotomy (38.4 vs 61.9%, AOR(95%CI)=0.43[0.24-0.78]) and was not associated with PPH (5.1 vs 5.9%, AOR=1.01[0.28-3.68]), pH<7.20, 5-min Apgar score < 7 (20.2 vs 15.9%, AOR=2.00[0.89-4.48]), lactates > 6 (23.0 vs 24.3, AOR=1.45[0.68-3.07]) or transfer to neonatal intensive care unit (6.2 vs 2.4%, AOR=4.71[0.76-29.08]. DiscussionExtending the duration of active second stage of labor beyond 45 min seems reasonable under rigorous surveillance of maternal and fetal wellbeing.

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

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. 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). 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. 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. 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.

3 Prophylactic Manual Rotation of Persistent Occiput Posterior to decrease operative Delivery: a Multicentric Randomized Trial

Persistent occiput posterior (POP) positions are the commonest malpresentations of the fetal head during labor and are associated with prolonged second stage of labor, cesarean, instrumental deliveries, obstetrical anal sphincter injuries, postpartum hemorrhage and chorioamnionitis. Manual rotation is one of several strategies described to deal with POP. The literature suggests that manual rotation of POP could decrease operative deliveries but no randomized study has confirmed these findings. The aim of this study was to determine if the trial of prophylactic manual rotation during the early second stage of labor is associated with a decrease risk of operative deliveries (instrumental and/or cesarean deliveries). This study was a prospective, randomized, controlled trial conducted in four French hospitals. Women with singleton term pregnancy and POP position confirmed by ultrasound at early second stage of labor and with epidural analgesia were eligible and randomized (1:1) to either receive the trial of prophylactic manual rotation of POP position (intervention group) or no trial of prophylactic manual rotation (standard group). The primary outcome was operative deliveries (instrumental and/or cesarean deliveries). From December 2015 to December 2019, 257 women were randomized: 126 assigned to the intervention group and 131 to the standard group. The groups did not differ in baseline characteristics. Operative delivery was significantly less frequent in the intervention (I) group compared to the standard (S) group (29.4 vs. 41.2%, p=.047, Differentiel (I-S) [95% confidence interval, CI] = -11.8 [-15.7;-7.9]; relative risk [95% CI] = 0.71 [0.51-1.00]). Women in the intervention group were more likely to have a significant shorter second stage of labor and have a neonate with a significant higher Apgar score at 5 minutes. The were no differences in other secondary outcomes. Trial of prophylactic manual rotation of persistent POP positions during the early second stage of labor is associated with a decrease risk of operative delivery.

512 Hands-and-knees position and incidence of occiput anterior position at birth: a systematic review and meta-analysis

Persistent occiput posterior (OP) and occiput transverse (OT) positions are associated with adverse maternal and neonatal outcomes. Our objective was to assess the efficacy of hands-and-knees to increase occiput anterior (OA) position in the second stage of labor or at time of delivery. An electronic search of five databases was performed. We included all randomized controlled trials of singleton gestations at ≥37 weeks that were randomized to either hands-and-knees position or control (i.e., any position other than hands-and-knees). The primary outcome was OA position in second stage of labor or at time of delivery. Secondary outcomes were change to OA position after initial intervention, as well as delivery and neonatal outcomes. A prespecified subgroup analysis for patients in labor was planned for the primary outcome. Meta-analysis was performed using the random-effects model expressed as relative risk (RR) or mean difference with 95% confidence intervals (CI). Heterogeneity was assessed using the I2 statistic. Of 1,079 studies screened, five met inclusion criteria (N=1,727 hands-and-knees position and N=1,641 controls). Duration of intervention varied from 10-60 minutes. Participants using hands-and-knees position did not have an increased rate of OA position during second stage of labor or at time of delivery (RR 1.03, 95% CI 0.92-1.14, 4 studies, 3,178 patients) or after initial intervention (RR 1.60, 95% CI 0.88-2.90, 4 studies, 788 patients). No difference was found on subgroup analysis of patients in labor (RR 1.06, 95% CI 0.87-1.29, 3 studies, 631 patients). Regional anesthesia use, duration of labor, rate of operative or cesarean deliveries, risk of perineal laceration, neonatal birth weight, and low Apgar scores did not differ between groups. Hands-and-knees position does not increase the incidence of OA position in labor or at time of delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

The role of the angle of progression in the prediction of the outcome of occiput posterior position in the second stage of labor

Occiput posterior position is the most frequent cephalic malposition, and its persistence at delivery is associated with a higher risk of maternal and perinatal morbidity. Diagnosis and management of occiput posterior position remain a clinical challenge. This is partly caused by our inability to predict fetuses who will spontaneously rotate into occiput anterior from those who will have persistent occiput posterior position. The angle of progression, measured with transperineal ultrasound, represents a reliable tool for the evaluation of fetal head station during labor. The relationship between the persistence of occiput posterior position and fetal head station in the second stage of labor has not been previously assessed. This study aimed to evaluate the role of fetal head station, as measured by the angle of progression, in the prediction of persistent occiput posterior position and the mode of delivery in the second stage of labor. We recruited a nonconsecutive series of women with posterior occiput position diagnosed by transabdominal ultrasound in the second stage of labor. For each woman, a transperineal ultrasound was performed to measure the angle of progression at rest. We compared the angle of progression between women who delivered fetuses in occiput anterior position and those with persistent occiput posterior position at delivery. Receiver operating characteristics curves were performed to evaluate the accuracy of the angle of progression in the prediction of persistent occiput posterior position. Finally, we performed a multivariate logistic regression to determine independent predictors of persistent occiput posterior position. Overall, 63 women were included in the analysis. Among these, 39 women (62%) delivered in occiput anterior position, whereas 24 (38%) delivered in occiput posterior position (persistent occiput posterior position). The angle of progression was significantly narrower in the persistent occiput posterior position group than in women who delivered fetuses in occiput anterior position (118.3°±12.2° vs 127.5°±10.5°; P=.003). The area under the receiver operating characteristics curve was 0.731 (95% confidence interval, 0.594-0.869) with an estimated best cutoff range of 121.5° (sensitivity of 72% and specificity of 67%). On logistic regression analysis, the angle of progression was found to be independently associated with persistence of occiput posterior position (odds ratio, 0.942; 95% confidence interval, 0.889-0.998; P=.04). Finally, women who underwent cesarean delivery had significantly narrower angle of progression than women who had a vaginal delivery (113.5°±8.1 vs 128.0°±10.7; P<.001). The area under the receiver operating characteristics curve for the prediction of cesarean delivery was 0.866 (95% confidence interval, 0.761-0.972). At multivariable logistic regression analysis including the angle of progression, parity, and gestational age at delivery, the angle of progression was found to be the only independent predictor associated with cesarean delivery (odds ratio, 0.849; 95% confidence interval, 0.775-0.0930; P<.001). In fetuses with occiput posterior at the beginning of the second stage of labor, narrower values of the angle of progression are associated with higher rates of persistent occiput posterior position at delivery and a higher risk of cesarean delivery.

Persistent occiput posterior position outcomes following manual rotation: a randomized controlled trial

Persistent occiput posterior position in labor is associated with adverse maternal and perinatal outcomes. Prophylactic manual rotation from the occiput posterior position to the occiput anterior position in the second stage of labor is considered a safe and easy to perform procedure that in observational studies has shown promise as a method for preventing operative deliveries. This study aimed to determine the efficacy of prophylactic manual rotation in the management of occiput posterior position for preventing operative delivery. The hypothesis was that among women who are at least 37 weeks pregnant and whose baby is in the occiput posterior position early in the second stage of labor, manual rotation will reduce the rate of operative delivery compared with the "sham" rotation. A double-blinded, parallel, superiority, multicenter, randomized controlled clinical trial in 4 tertiary hospitals was conducted in Australia. A total of 254 nulliparous and parous women with a term pregnancy and a baby in the occiput posterior position in the second stage of labor were randomly assigned to receive either a prophylactic manual rotation (n=127) or a sham rotation (n=127). The primary outcome was operative delivery (cesarean, forceps, or vacuum delivery). Secondary outcomes were cesarean delivery, combined maternal mortality and serious morbidity, and combined perinatal mortality and serious morbidity. Analysis was by intention to treat. Proportions were compared using chi-square tests adjusted for stratification variables using the Mantel-Haenszel method or the Fisher exact test. Planned subgroup analyses by operator experience and by manual rotation technique (digital or whole-hand rotation) were performed. Operative delivery occurred in 79 of 127 women (62%) assigned to prophylactic manual rotation and 90 of 127 women (71%) assigned to sham rotation (common risk difference, 12; 95% confidence interval,-1.7 to 26; P=.09). Among more experienced operators or investigators, operative delivery occurred in 46 of 74 women (62%) assigned to manual rotation and 52 of 71 women (73%) assigned to a sham rotation (common risk difference, 18; 95% confidence interval,-0.5 to 36; P=.07). Cesarean delivery occurred in 22 of 127 women (17%) in both groups. Instrumental delivery (forceps or vacuum) occurred in 57 of 127 women (45%) assigned to prophylactic manual rotation and 68 of 127 women (54%) assigned to sham rotation (common risk difference, 10; 95% confidence interval,-3.1 to 22; P=.14). There was no significant difference in the combined maternal and perinatal outcomes. Prophylactic manual rotation did not result in a reduction in the rate of operative delivery. Given manual rotation was associated with a nonsignificant reduction in operative delivery, more randomized trials are needed, as our trial might have been underpowered. In addition, further research is required to further explore the potential impact of operator or investigator experience.

Factors affecting failed trial of labor and countermeasures: A retrospective analysis.

BACKGROUNDVaginal delivery is the ideal mode of delivery for the termination of a pregnancy. However, the cesarean section rate in China is much higher than the published by the World Health Organization in the Lancet in 2010.AIMTo retrospectively analyze the factors related to failed trial of labor and the clinical indications for cesarean section conversion, explore how to promote the trial of labor success rate, and determine the feasibility of reducing the rate of conversion to cesarean section.METHODSA retrospective analysis was performed on 9240 maternal women who met vaginal delivery conditions and required a trial of labor from January 2016 to December 2018 at our hospital. Among them, 8164 pregnant women who had a successful trial of labor were used as a control group, and 1076 pregnant women who had a failed trial of labor and converted to an emergency cesarean section were used as an observation group. The patients’ clinical data during hospitalization were collected for comparative analysis, the related factors of the failed trial of labor were discussed, and reasonable prevention and resolution strategies were proposed to increase the success rate of trial of labor.RESULTSThe analysis revealed that advanced age (≥ 35 years old), macrosomia (≥ 4000 g), delayed pregnancy (≥ 41 wk), use of uterine contraction drugs, primipara, and fever during labor were associated with conversion to an emergency cesarean section in the failed trial of labor. Multivariate regression analysis showed that age, gestational age, primipara, use of uterine contraction drugs, fever during birth, and newborn weight led to a higher probability of conversion to an emergency cesarean section in the failed trial of labor. The analysis indicated that the following clinical indications were associated with the conversion to cesarean section in the failed trial of labor: Fetal distress (44.3%), social factors (12.8%), malpresentation (face presentation, persistent occipitoposterior position, and persistent occipitotransverse position) (9.4%), and cephalopelvic disproportion (8.9%).CONCLUSIONThe conversion to emergency cesarean section in failed trial of labor is affected by many factors. Medical staff should take appropriate preventive measures for the main factors, increase the trial of labor success rate, improve the quality of delivery, ensure the safety of mother and child during the perinatal period, and improve the relationship between doctors and patients.

A possible case of dystocia due to foetal macrosomia at Shuanghuaishu site (3500–2900 BCE), Henan, China

AbstractChildbirth was a significant factor in ancient female mortality, but relatively few cases of death in childbirth have been reported in the bioarchaeological literature due to challenges of recovery and interpretation. Here, we report a possible case of dystocia from the late Neolithic (3500–2900 BCE) settlement of Shuanghuaishu site (Gongyi City, Henan Province, China). An adult female skeleton was discovered in an inhumation burial with the remains of a foetus in the pelvis. The top of the foetal skull has exited the pelvic outlet, but most of the head remains in the pelvic cavity. The face is oriented away from the mother's spine, indicating that the foetus was in persistent occipitoposterior position. In modern deliveries, this atypical positioning is associated with complications including prolonged labour and excessive maternal bleeding. Long bone measurements indicate that the foetus was large compared with full‐term modern infants. This may indicate foetal macrosomia, which is also associated with prolonged and difficult labour. These indicators suggest that this was a case of dystocia, with the large size and positioning of the foetus leading to obstructed labour and the death of both mother and infant. The presence of some cranial remains outside the pelvic outlet could represent either partial delivery of the head or partial post mortem delivery (coffin birth). This paper provides an example of the interpretive challenges facing researchers investigating reproductive mortality in ancient China and in other past societies.

Intrapartum Care

Intrapartum care encompasses the treatment of pregnancy during labor and delivery. Knowledge of the normal labor process is essential to effectively recognize and treat abnormalities, and thus optimize maternal and fetal health. This review aims to outline the physiology of labor and discuss contemporary features of spontaneous labor, prolonged labor, and arrest of labor. It addresses management of group B streptoccocous colonization and electronic fetal monitoring practices. Additionally, issues associated with term labor such as prelabor rupture of membranes, abruption, intrapartum intraamniotic infection, and persistent occiput posterior position are discussed. The review concludes with a brief overview of delivery methods. This review contains 7 figures, 14 tables, and 49 references. Keywords: term labor, intrapartum monitoring, induction of labor, Group B Streptococcous prophylaxis, prelabor rupture of membranes, intraamniotic infection, mode of delivery

Persistent occiput posterior position and stress distribution in levator ani muscle during vaginal delivery computed by a finite element model

Introduction and hypothesisObjective of this study was to develop an MRI-based finite element model and simulate a childbirth considering the fetal head position in a persistent occiput posterior position.MethodsThe model involves the pelvis, fetal head and soft tissues including the levator ani and obturator muscles simulated by the hyperelastic nonlinear Ogden material model. The uniaxial test was measured using pig samples of the levator to determine the material constants. Vaginal deliveries considering two positions of the fetal head were simulated: persistent occiput posterior position and uncomplicated occiput anterior position. The von Mises stress distribution was analyzed.ResultsThe material constants of the hyperelastic Ogden model were measured for the samples of pig levator ani. The mean values of Ogden parameters were calculated as: μ1 = 8.2 ± 8.9 GPa; μ2 = 21.6 ± 17.3 GPa; α1 = 0.1803 ± 0.1299; α2 = 15.112 ± 3.1704. The results show the significant increase of the von Mises stress in the levator muscle for the case of a persistent occiput posterior position. For the optimal head position, the maximum stress was found in the anteromedial levator portion at station +8 (mean: 44.53 MPa). For the persistent occiput posterior position, the maximum was detected in the distal posteromedial levator portion at station +6 (mean: 120.28 MPa).ConclusionsThe fetal head position during vaginal delivery significantly affects the stress distribution in the levator muscle. Considering the persistent occiput posterior position, the stress increases evenly 3.6 times compared with the optimal head position.

Republication de : Variétés postérieures au cours du travail : mécanique obstétricale, diagnostic et prise en charge

Persistant occiput posterior (OP) positions are the commonest malpresentations of the fetal head during labor and their diagnosis remains challenging. They are associated to prolonged second stage of labor, prolonged expulsive efforts, labor augmentation, cesarean sections and instrumental deliveries. On the maternal side, severe perineal tears, post-partum hemorrhage or chorioamnionitis are more frequent. Currently, prevention of persistent OP positions is based on the maintain of precise maternal positions. Several positions have been evaluated but only lateral position on the same side of the fetal spine has proved its effectiveness. Fetal head rotation can also be achieved with extraction instruments though none has ever been evaluated by a randomized controlled trial. Obstetrical forceps seem more efficient than vacuum but are associated with severe perineal tears. Evaluation of rotation with Thierry's spatulas is scarce. Last, manual rotation is of routine use in many wards. This management is associated with a twofold reduction of operative delivery rate and rare adverse outcomes but has never been evaluated through randomized control trial.