Occiput Posterior Position Research Articles

Rebozo and advanced maternal postures: A promising set of intrapartum interventions to reduce persistent occiput posterior position of the fetal head.

Spinning Babies® procedures and the Rebozo technique have been recently implemented as additional interventions in laboring women with a fetus in occiput posterior position (OPP) to favor the rotation to an anterior position, which improve birth experience and health outcomes. Our study aimed to compare the probability of occurrence of persistent OPP (POPP) of the fetal head at the second stage of labor between retrospective and prospective cohorts and to assess associated sociodemographic, obstetric and intrapartum factors. We conducted a combined prospective and retrospective cohort study including 1500 women giving birth in 2017 (retrospective cohort) and 779 between 15 May and 15 December 2023 (prospective cohort). Each cohort was divided into two sub-cohorts depending on presence of OPP. Primary outcomes were compared the probability of occurrence of POPP in the two OPP sub-cohorts by a log binomial regression and logistic regression. A p<0.05 was considered statistically significant. Data analysis was performed using Stata/MP18.0. The proportion of OPP at the onset of labor was similar between the two cohorts (34.9% vs 35.1%). The probability of occurrence of POPP was significantly lower in the prospective OPP sub-cohort (27.7%, n=65/235) compared to the retrospective OPP sub-cohort (35.8%, n=154/430) (risk difference, RD= -0.081; 95% CI: -0.15 - -0.008; p=0.031). In the retrospective OPP sub-cohort, maternal age ≥35 years (RD=0.096; 95% CI: 0.001-0.190, p=0.044) and nulliparity (RD= -0.100; 95% CI: -0.190 - -0.001, p=0.036) were significantly associated with the probability of POPP. Our findings suggest a potential benefit of a set of interventions combining Spinning Babies® and the Rebozo technique in decreasing the probability of POPP.

Intrapartum Ultrasound Guidance to Make Safer Any Obstetric Intervention: Fetal Head Rotation, Assisted Vaginal Birth, Breech Delivery of the Second Twin.

Intrapartum ultrasound (US) is more reliable than clinical assessment in determining parameters of crucial importance to optimize the management of labor including the position and station of the presenting part. Evidence from the literature supports the role of intrapartum US in predicting the outcome of labor in women diagnosed with slow progress during the first and second stage of labor, and randomized data have demonstrated that transabdominal US is far more accurate than digital examination in assessing fetal position before performing an instrumental delivery. Intrapartum US has also been shown to outperform the clinical skills in predicting the outcome and improving the technique of instrumental vaginal delivery. On this basis, some guidelines recommend intrapartum US to ascertain occiput position before performing an instrumental delivery. Manual rotation of occiput posterior position (MROP) and assisted breech delivery of the second twin are other obstetric interventions that can be performed during the second stage of labor with the support of intrapartum US. In this review article we summarize the existing evidence on the role of intrapartum US in assisting different types of obstetric intervention with the aim to improve their safety.

A deep learning approach to identify the fetal head position using transperineal ultrasound during labor

ObjectivesTo develop a deep learning (DL)-model using convolutional neural networks (CNN) to automatically identify the fetal head position at transperineal ultrasound in the second stage of labor. Material and methodsProspective, multicenter study including singleton, term, cephalic pregnancies in the second stage of labor. We assessed the fetal head position using transabdominal ultrasound and subsequently, obtained an image of the fetal head on the axial plane using transperineal ultrasound and labeled it according to the transabdominal ultrasound findings. The ultrasound images were randomly allocated into the three datasets containing a similar proportion of images of each subtype of fetal head position (occiput anterior, posterior, right and left transverse): the training dataset included 70 %, the validation dataset 15 %, and the testing dataset 15 % of the acquired images. The pre-trained ResNet18 model was employed as a foundational framework for feature extraction and classification. CNN1 was trained to differentiate between occiput anterior (OA) and non-OA positions, CNN2 classified fetal head malpositions into occiput posterior (OP) or occiput transverse (OT) position, and CNN3 classified the remaining images as right or left OT. The DL-model was constructed using three convolutional neural networks (CNN) working simultaneously for the classification of fetal head positions. The performance of the algorithm was evaluated in terms of accuracy, sensitivity, specificity, F1-score and Cohen’s kappa. ResultsBetween February 2018 and May 2023, 2154 transperineal images were included from eligible participants across 16 collaborating centers. The overall performance of the model for the classification of the fetal head position in the axial plane at transperineal ultrasound was excellent, with an of 94.5 % (95 % CI 92.0––97.0), a sensitivity of 95.6 % (95 % CI 96.8–100.0), a specificity of 91.2 % (95 % CI 87.3–95.1), a F1-score of 0.92 and a Cohen’s kappa of 0.90. The best performance was achieved by the CNN1 – OA position vs fetal head malpositions – with an accuracy of 98.3 % (95 % CI 96.9–99.7), followed by CNN2 – OP vs OT positions – with an accuracy of 93.9 % (95 % CI 89.6–98.2), and finally, CNN3 – right vs left OT position – with an accuracy of 91.3 % (95 % CI 83.5–99.1). ConclusionsWe have developed a DL-model capable of assessing fetal head position using transperineal ultrasound during the second stage of labor with an excellent overall accuracy. Future studies should validate our DL model using larger datasets and real-time patients before introducing it into routine clinical practice.

Associations between fetal position at delivery and duration of active phase of labor: A historical cohort study.

In clinical experience, occiput posterior (OP) position is associated with longer labor duration than occiput anterior (OA) position, but few studies have investigated the association between labor duration and fetal position. We aimed to compare duration of the active phase of labor in OP deliveries with OA deliveries in a contemporary population using survival methods. Secondary aims were to compare the frequencies of operative interventions, obstetric anal sphincter injuries (OASIS), postpartum hemorrhage, and newborn outcomes in OP with OA deliveries. We did a historical cohort study in three university hospitals in Norway from 2012 to 2022. Women with a single fetus in cephalic presentation, no previous cesarean section and gestational age ≥37 weeks were eligible and stratified into the first four groups of the Robson ten-group classification system (TGCS). We estimated the mean duration and calculated the hazard ratio (HR) for delivery using survival analyses. Cesarean sections and instrumental vaginal deliveries were censored. The study population comprised 112 019 women, 105 571 (94.2%) were delivered in OA and 6448 (5.8%) in OP position. The estimated mean duration of the active phase of labor was longer in women with the fetus in OP position in all four TGCS groups. The estimated duration was longer in the OP groups in analyses stratified with respect to epidural analgesia and oxytocin augmentation. The graphical abstract illustrates the probability of delivery in OP compared with OA position in merged TGCS groups 1 and 2a, as a function of time. The unadjusted HR was 0.33 (95% CI 0.31-0.36) for fetuses delivered in OP position compared with OA position in TGCS group 1, 0.25 (95% CI 0.21-0.27) in group 2a, 0.70 (95% CI 0.67-0.73) in group 3, and 0.61 (95% CI 0.55-0.67) in group 4a, respectively. Neither maternal age, gestational age, BMI nor birthweight had confounding effect. Operative delivery rates and OASIS rates were higher in OP position in all four groups. We found longer duration of the active phase of labor in women with the fetus delivered in OP position in all four TGCS groups.

A national survey of clinicians’ opinions of rotational vaginal births

IntroductionMalposition of the fetal head, defined as occiput transverse or posterior positions, occurs in approximately 5% of births. At full cervical dilatation, fetal malposition is associated with an increased risk of rotational vaginal birth. There are three different rotational methods: manual rotation, rotational ventouse or rotational (Kielland’s) forceps. In the absence of robust evidence, it is not currently known which of the three methods is most efficacious, and safest for parents and babies. ObjectiveTo gain greater insights into opinions and preferences of rotational birth to explore the acceptability and feasibility of performing a randomised trial comparing different rotational methods. Material and methodsA survey was sent via email to obstetricians from the British Maternal Fetal Medicine Society, as well as expert obstetricians and active academics in ongoing research in the UK. The questions focussed on perceived competence, preferred rotational method, location (theatre or labour room), willingness to recruit to an RCT, and its outcome measures. Closed questions were followed by the option of free text to allow further comments. The free text answers underwent thematic analysis. Results252 consultant obstetricians responded. The majority stated they were competent in performing manual rotation (88.1%). Half felt proficient using Kielland’s rotational forceps (54.4%). Most obstetricians felt skilled in rotational ventouse (76.2%). Manual rotation was the preferred first rotational method of choice in cases of both occiput transverse and posterior positions. The decision for which rotational method to attempt first was considered case-dependent by many. Two thirds of obstetricians would usually conduct rotational births in theatre (67.9%). Over half (52%) do not routinely use intrapartum ultrasound. Most (62.7%) would be willing to recruit to a randomised controlled trial comparing manual versus instrumental rotation. Over half (57.2%) would be willing to recruit to the same RCT if they were the most senior doctor competent in rotational vaginal birth supervising a junior. ConclusionThere is a wide range of practice in conducting rotational vaginal births in the UK. An RCT to investigate the impact of different rotational methods on outcome would be both feasible and desirable, especially in research-active hospitals.

Factors Associated with Obstetric Anal Sphincter Injury During Vacuum-Assisted Vaginal Delivery.

Obstetric anal sphincter injury (OASI) is a major complication associated with vacuum-assisted vaginal delivery (VAVD). The aim of this study was to evaluate risk factors related to vacuum extraction that are associated with OASI. This was a case-control study performed at a tertiary university teaching hospital. Included were patients aged 18-45years who had a singleton pregnancy resulting in a live, term, VAVD. The study group consisted of women diagnosed with OASI following vacuum extraction. The control group included women following VAVD without OASI. Matching at a ratio of 1:2 was performed. Groups were compared regarding demographic, obstetric. and labor-related parameters, specifically focusing on variables related to the vacuum procedure itself. One hundred and ten patients within the study group and 212 within the control group were included in the final analysis. Patients in the OASI group were more likely to undergo induction of labor, use of oxytocin during labor, increased second stage of labor, higher likelihood of the operator being a resident, increased number of pulls, procedure lasting under 10min, occipito-posterior head position at vacuum initiation, episiotomy, increased neonatal head circumference, and birthweight. Multivariate logistic regression analysis revealed that increased week of gestation (OR 1.67, 95% CI 1.25-2.22, p < 0.001), unsupervised resident performing the procedure (OR 4.63, 95% CI 2.17-9.90), p < 0.001), indication of VAVD being fetal distress (OR 2.72, 95% CI 1.04-7.10, p = 0.041), and length of procedure under 10min (OR 4.75, 95% CI 1.53-14.68, p = 0.007) were associated with OASI. Increased maternal age was associated with lower risk of OASI (OR 0.9, 95% CI 0.84-0.98, p = 0.012). When performing VAVD, increased week of gestation, unsupervised resident performing the procedure, fetal distress as vacuum indication, and vacuum procedure under 10min were associated with OASI. In contrast, increased maternal age was shown to be a protective factor.

Do Birth Outcomes Predicted by Occipital Position Inform Definitions of Occiput Posterior and Occiput Transverse?

Fetal head position significantly influences birth outcomes, with higher rates of complications observed when the fetal head is in the Occiput Posterior (OP) position compared to Occiput Transverse (OT) or Occiput Anterior (OA) positions. There is no consensus in the current literature on the precise rotational point at which the fetal occiput shifts from posterior to transverse, reducing clarity in both scientific and clinical communication. Different studies employ varying definitions of these positions, which affects management decisions. This study aims to determine if a definable threshold exists between the directly posterior and directly transverse positions that correlates with different birth outcomes, thereby proposing a consistent and clinically useful definition for OP versus OT. We analyzed ultrasound data from 570 patients at full dilatation from five previous studies, correlating the angle of the fetal occiput (noted on a clock-face) with birth outcomes. Adverse outcomes were defined as cesarean delivery, instrumental vaginal delivery, significant postpartum hemorrhage (500 ml or more), obstetric anal sphincter injury, five-minute Apgar scores <7, arterial cord pH <7, base excess less than -12, or neonatal intensive care unit admission. The analysis was conducted using SAS version 9.4. The study found a continuous relationship between the fetal occipital angle and adverse birth outcomes without a distinct threshold separating OP from OT positions. No clear inflection point was demonstrated in pregnancy outcomes between OT and OP. The relationship between the angle of occiput position and pregnancy outcomes was continuous: the closer the fetal head was to directly OP, the higher the likelihood of adverse outcomes. Given the lack of a clear cut-off and to improve consistency in future research, we recommend dividing the occiput position into four quadrants of 90 degrees each. This classification could standardize reporting and potentially improve clinical decision-making regarding fetal position during labor.

Perinatal Outcomes and Level of Labour Difficulty in Deliveries with Right and Left Foetal Position-A Preliminary Study.

Many studies have shown the negative influence of the foetus's occiput posterior position during birth on the final perinatal outcome. This study aims to add to the discussion on the impact of foetus positioning on the course of labour and subjective assessment of the level of labour difficulty. The cross-sectional study took place from February 2020 to September 2021, and consisted of filling out observation forms and the assessment by the midwives and women of the level of labour difficulty. This study is based on the observation of 152 labours in low-risk women. When compared to left foetal positioning, labours in which the foetus was in the right position were longer and more frequently failed to progress (in 11.3% vs. 37.5%), and epidural was more frequently administrated (in 30.4% vs. 52.7%). Both women and midwives subjectively evaluated deliveries with a foetus in the right position as more difficult. The right positioning of the foetus was related to greater labour difficulty and worse perinatal outcomes. The position of the foetus' head in relation to the pelvis should be considered as an indicator of the difficulty of labour and a support plan for the woman should be offered accordingly.

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.

Risk factors associated with severe perineal tear at Public Hospitals in Bahir Dar town, Northwest Ethiopia

Background: Birth-related perineal trauma is a public health issue that can lead to significant maternal morbidity in low-income countries like Ethiopia. Research on the proportion and underlying factors of birth-related severe perineal tears is rare, both in the study area and throughout Ethiopia. As a result, this study was intended to determine the proportion of birth-related severe perineal tears and associated factors at hospitals in Bahir Dar town, Ethiopia. Methods: A cross-sectional study was undertaken at government hospitals in Bahir Dar, Ethiopia. Five hundred fifteen study subjects were selected using a systematic sampling technique. The data was collected through chart reviews and interviews. Data was entered and analyzed using SPSS Version 23. A binary logistic regression was employed to identify factors, and an adjusted odds ratio and a 95% CI were used to estimate the strength of relationships. Statistical significance was declared at p-value &lt; 0.05. Result: The prevalence of severe perineal tears was 7.4%. Previous history of a perineal tear (AOR = 3.06, 95% CI = 1.24–7.59), being nullipara (AOR = 4.03, 95% CI = 1.42–11.44), occipito-posterior position (AOR = 5.49, 95% CI = 2.27–13.28), duration of second stage of labor &gt; 2 h (AOR = 5.42, 95% CI = 2.26–12.99), birth attendant’s work experience &lt;1 year (AOR = 5.98, 95% CI = 2.16–16.57) were found to be associated with birth-related severe perineal tear. Conclusion: The proportion of birth-related severe perineal tears was high at governmental hospitals in Bahir Dar town. Previous history of perineal tear, work experience of birth attendants, duration of the second stage of labor, being nullipara, and occipito-posterior position were the major determinants of severe perineal tear. This study suggests that strategies and regulations should be developed to shorten the second stage of labor.

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.

OP01.06: The value of one‐eye versus two‐eyes sign in the prediction of labour outcome in cases of occiput posterior position in active labour

OP01.06: The value of one‐eye versus two‐eyes sign in the prediction of labour outcome in cases of occiput posterior position in active labour

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.

The Impact of Maternal Position in Labor on Occiput-Posterior Position of Fetus and Pregnancy Outcomes in Pregnant Women Without Epidural Analgesia.

Fetal occiput posterior (OP) position is associated with more maternal and neonatal complications. This study aimed to investigate the effect of maternal position during labor on fetal OP position and pregnancy outcomes. This randomized clinical trial study included 180 primigravida women in labor with a single fetus and approved OP position. Participants were randomly allocated into three groups: semi-prone position (n=45), knee-chest position (n=45), and supine position (n=90). All participants were placed in the defined positions 15-30 min in labor until delivery. Data collected using Visual Analogue Scale and researcher made checklist. The ANOVA, Tukey post hoc, and the chi-square test were used to analyze. Among all participants who had OP, after intervention 16.3% in the semi-prone position, 14/3 % in the knee-chest position, and 33.7% of the control groups remained with OP at birth (X3=7/87, P=0.019). The rate of natural delivery was significantly higher in the semi-prone position and knee-chest position. The duration of active phase of labor and low back pain were significantly reduced in the semi-prone and knee-chest position compared to the control groups (P<0.05). There were no differences in the duration of the third stage of labor, APGAR score, and the rate of neonatal addition to neonatal intensive care unit, using oxytocin, and perineal tears (P>0.05). The semi-prone and knee-chest positions increase the spontaneous rotation of occiput to the anterior position, vaginal delivery rates as well as a reduction in duration of active phase of labor and low back pain after delivery.

The Benefits of Manual Rotation in The Treatment of Occiput Posterior Position: A Case Study of Iraq

The Benefits of Manual Rotation in The Treatment of Occiput Posterior Position: A Case Study of Iraq

Use of Fetal Occiput – Spinal Angle at Early Active Phase of First Stage of Labour in Predicting the Labour Outcome – A CrossSectional Observational Study

Introduction: Fetal head deflexion plays an important role during the labour process and predicts the outcome of labour. Though traditionally it was assessed via digital examination, recent advancements in medicine have shown ultrasonographic parameters might be useful to measure of head flexion via fetal occiput-spine angle (OSA). Aim of this study was to evaluate its role. Method: We conducted a cross-sectional observational study on 292 uncomplicated singleton pregnant mothers without occiput posterior position. At early active phase of labour (OS= 4 – 6cm), angle between two tangential lines to the occipital bone and the vertebral body of the first cervical vertebra was measured as OSA. Labour progression and mode of delivery was monitored. Association between OSA and labour outcome along with the inter-observer difference was evaluated. Results: The mean OSA value was 133.88 ± 7.39°. The OSA measurement showed good inter-observer agreement (r = 0.99; p&lt;0.001). The mean OSA was significantly less for the group of patients who had to undergo operative delivery (instrumental and cesarean) due to labour dystocia (n=37) as compared to women who had vaginal delivery (n=251), (128 ± 7.28° vs 134.83 ± 6.97°, P&lt;0.001). The mean OSA was significantly greater for the group of patients who had a normal labour progression (n=32) as compared to women who had an abnormal progression (n=260), (134.67 ± 7.06° vs 127.47 ± 6.99°, P&lt;0.001). Sonographic assessment of deflexion using OSA was found to be an independent predictor of labour outcome according to multivariate regression analysis. OSA value less than 127.8° was associated with abnormal labour progression and operative delivery with a good sensitivity of 86.5% &amp; 85% respectively. However negative predictive value for operative delivery being 6.8%, suggests that multiple clinical parameters should be considered when the decision of caesarean section is made. Conclusion: Sonographic assessment of fetal head deflexion during early active phase can be used as reproducible, feasible screening parameter to predict labour progression and mode of delivery. Decision for operative delivery should be made using multiple clinical assessments.

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.

Latent phase duration and associated outcomes: a contemporary, population-based observational study

Little is known about the latent phase of labor, including whether its duration influences subsequent labor processes or birth outcomes. This study aimed to describe the duration of the latent phase of labor from self-report of the onset of painful contractions to a cervical dilation of 5 cm in a large, Swedish population and evaluate the association between the duration of the latent phase of labor and perinatal processes and outcomes that occurred during the active phase of labor, second stage of labor, birth and immediately after delivery, stratified by parity. This was a population-based cohort study of 67,267 pregnancies with deliveries between 2008 and 2020 in the Stockholm-Gotland Regions, Sweden. Nulliparous and parous women without a history of cesarean delivery in spontaneous labor with a term (≥37 weeks of gestation), singleton, live, and vertex fetus without major malformations were included. Imputation was used if the notation of the end of the latent phase of labor (ie, cervical dilation of 5 cm) was missing in the partograph. Multivariable logistic regression was used to estimate the association with adjusted odds ratios and 95% confidence intervals, controlling for potential covariates. Including the time from painful contraction onset to a cervical dilation of 5 cm, the median durations of the latent phase of labor were 16.0 (interquartile range, 10.0-26.6) hours for nulliparous women and 9.4 (interquartile range, 5.9-15.3) hours for multiparous women. The durations of the latent phase of labor beyond the median were associated with increased odds of labor dystocia diagnosis during the first stage active phase or second stage of labor and interventions commonly associated with dystocia (amniotomy, oxytocin augmentation, epidural, and cesarean delivery). The duration of the latent phase of labor of ≥90th percentile vs less than the median in nulliparous women demonstrated an increased risk of adverse neonatal outcomes (Apgar score of <7 at 5 minutes and neonatal intensive care unit admission), chorioamnionitis, and fetal occiput posterior. In multiparous women, longer duration of the latent phase of labor was associated with an increased risk of neonatal intensive care unit admission and chorioamnionitis but was not associated with an Apgar score of <7 at 5 minutes. The duration of the latent phase of labor was not associated with additional markers of maternal risk. The duration of the latent phase of labor in nulliparous women was longer than that of multiparous women at each point of distribution. A longer duration of the latent phase of labor was associated with more frequent dystocia diagnoses and related interventions during the first stage active phase or second stage of labor, including cesarean delivery, nulliparous fetal occiput posterior position, chorioamnionitis, and markers of neonatal morbidity. More research is needed to identify potential mediating paths between the duration of the latent phase of labor and neonatal morbidity.

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.