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

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.

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

BACKGROUND

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.

METHODS

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.

FINDINGS

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.

CONCLUSIONS

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.

Sonographic evaluation of the fetal head position and attitude during labor

Fetal malpresentation, malposition, and asynclitism are among the most common determinants of a protracted active phase of labor, arrest of dilatation during the first stage, and arrest of descent in the second stage. The diagnosis of these conditions is traditionally based on vaginal examination, which is subjective and poorly reproducible. Intrapartum sonography has been demonstrated to yield higher accuracy than vaginal examination in characterizing fetal malposition, and some guidelines endorse its use for the verification of the occiput position before performing an instrumental delivery. It is also useful for the objective diagnosis of the malpresentation or asynclitism of the fetal head. According to our experience, the sonographic assessment of the head position in labor is simple to perform also for clinicians with basic ultrasound skills, whereas the assessment of malpresentation and asynclitism warrants a higher level of expertise. When clinically appropriate, the fetal occiput position can be easily ascertained using transabdominal sonography combining the axial and the sagittal planes. With the transducer positioned on the maternal suprapubic region, the fetal head can be visualized, and landmarks including the fetal orbits, the midline, and the occiput itself with the cerebellum and the cervical spine (depending on the type of fetal position) can be demonstrated below the probe. Sinciput, brow, and face represent the 3 "classical" variants of cephalic malpresentation and are characterized by a progressively increasing degree of deflexion from vertex presentation. Transabdominal sonography has been recently suggested for the objective assessment of the fetal head attitude when a cephalic malpresentation is clinically suspected. Fetal attitude can be evaluated on the sagittal plane with either a subjective or an objective approach. Two different sonographic parameters such as the occiput-spine angle and the chin-chest angle have been recently described to quantify the degree of flexion in fetuses in non-occiput-posterior or occiput-posterior position, respectively. Finally, although clinical examination still represents the mainstay of diagnosis of asynclitism, the use of intrapartum sonography has been shown to confirm the digital findings. The sonographic diagnosis of asynclitism can be achieved in expert hands using a combination of transabdominal and transperineal sonography. At suprapubic sonography on the axial plane only, 1 orbit can be visualized (squint sign) while the sagittal suture appears anteriorly (posterior asynclitism) or posteriorly (anterior asynclitism) displaced. Eventually the transperineal approach does not allow the visualization of the cerebral midline on the axial plane if the probe is perpendicular to the fourchette. In this expert review we summarize the indications, technique, and clinical role of intrapartum sonographic evaluation of fetal head position and attitude.

Prediction of persistent occiput posterior position by sonographic assessment of fetal head attitude at start of second stage of labor: prospective study

OBJECTIVES

To evaluate the relationship between the attitude of the fetal head quantified by means of the chin-to-chest angle (CCA) in fetuses in occiput posterior (OP) position at the beginning of the second stage of labor, and persistent OP position at birth.

METHODS

This was a single-center, prospective observational study conducted at the University Hospital of Parma, Parma, Italy. We included singleton pregnancies at term with fetuses in the OP position at the beginning of the second stage of labor. The fetal head position, station by means of angle of progression and head-to-perineum distance, and attitude by means of CCA were assessed using transabdominal or transperineal ultrasound. The primary outcome was persistent OP position at birth.

RESULTS

Between January and July 2022, 76 women were included in the study. There were 48 (63.2%) spontaneous rotations of the fetal head and spontaneous vaginal delivery occurred in all. Among the 28 (36.8%) fetuses that did not rotate spontaneously into an occiput anterior position, eight (28.6%) had a spontaneous vaginal delivery, while operative vaginal delivery and Cesarean delivery was performed in 11 (39.3%) and nine (32.1%) cases, respectively. Multivariable logistic regression analysis showed that the CCA (adjusted odds ratio (aOR), 2.15 (95% CI, 1.22-3.78); P = 0.008) and nulliparity (aOR, 0.20 (95% CI, 0.06-0.76); P = 0.02) were associated independently with persistent OP position at birth. Moreover, the CCA showed an area under the receiver-operating-characteristics curve of 0.69 (95% CI, 0.56-0.82); P = 0.005) for the prediction of persistent OP position. The optimal cut-off value of the CCA was 36.5°, and was associated with a sensitivity of 0.82 (95% CI, 0.63-0.94), specificity of 0.50 (95% CI, 0.35-0.65), positive predictive value of 0.49 (95% CI, 0.34-0.64), negative predictive value of 0.83 (95% CI, 0.64-0.94), positive likelihood ratio of 1.64 (95% CI, 1.18-2.29) and negative likelihood ratio of 0.36 (95% CI, 0.15-0.83).

CONCLUSIONS

Our data show that, within a population of women with fetal OP position at the beginning of the second stage of labor, the sonographic fetal head attitude measured by means of the CCA might help in the identification of fetuses at risk of persistent OP position. Such findings can be useful for patient counseling when OP position is diagnosed at full cervical dilatation. Further studies should investigate if the CCA might select patients who may benefit from manual rotation of the fetal head. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Internal manual rotation in intrapartal arrest of fetal head engagement

OBJECTIVE

The success of internal manual or digital rotation of the head in mechanical dystocia due to malpresentation, malposition or malrotation is presented in this paper on our own clinical material with reference of today's research and clinical recommendations.

STUDY DESIGN

Through a retrospective bicentric clinical study, we investigated the success of internal head rotation in two University Clinics for gynecology and obstetrics from year 2017 to 2023. In 152 singleton term (37-42 weeks) in cases of persistens intrapartum arrest of the fetal head. After palpatory and ultrasonographically verified arrest of fetal head engagement, a therapeutic manual (Liepmann) or digital rotation was performed.

RESULTS

In 152 cases, manual rotation was performed in 108 (71.05 %) and digital rotation in 44 (28.94 %) cases in 73 (48.02 %) primiparous and 79 (51.97 %) multiparous. Intrapartum identification by digital palpation was done in all cases, and the following are: persistent occipital posterior position in 68 (44.73%), persistent deep transverse head presentation in 12 (7.89%), persistent high (longitudinal) occipital presentation in 64 (42.10 %) and persistent anterior asynclitism in 8 (5.26 %) cases. Episiotomy was used in 36 (23.68%) cases. Vacuum extraction was completed in 14 (9.21 %) deliveries, and cesarean section due to unsuccessful internal rotation in 15 (9.8 %) cases (%) without other indication. We did not record any intrapartum complications or cardiotocographic abnormalities. Cervical lacerations were treated with sutures in 4 cases (2.63 %). Successful correction of internal rotation procedure with spontaneous vaginal delivery was found in 80.92 % of cases. If we exclude delivery assisted by vacuum extraction whose indications were fetal hypoxia or dystocia after successful internal head rotation procedure, then the success rate of this method was 90.13 %.

CONCLUSION

Internal head rotation is a simple, safe and successful obstetric manual intervention that directly increases the rate of vaginal deliveries after correction of the birth mechanism anomaly and directly reduces the percentage of cesarean section. Manual or digital head rotation is an established midwifery/obstetric skill in several centers which, based on numerous clinical researches and experience, should become protocolized and included in the guidelines of professional associations.

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.

Midwife led randomised controlled trials in Australia and New Zealand: A scoping review

BACKGROUND

Midwives are the largest workforce involved in caring for pregnant women and their babies, and are well placed to translate research into practice and ensure midwifery priorities are appropriately targeted in researched. Currently, the number and focus of randomised controlled trials led by midwives in Australia and New Zealand is unknown. The Australasian Nursing and Midwifery Clinical Trials Network was established in 2020 to build nursing and midwifery research capacity. To aid this, scoping reviews of the quality and quantity of nurse and midwife led trials were undertaken.

AIM

To identify midwife led trials conducted between 2000 and 2021 in Australia and New Zealand.

METHODS

This review was informed by the JBI scoping review framework. Medline, Emcare, and Scopus were searched from 2000-August 2021. ANZCTR, NHMRC, MRFF, and HRC (NZ) registries were searched from inception to July 2021.

FINDINGS

Of 26,467 randomised controlled trials registered on the Australian and New Zealand Clinical Trials Registry, 50 midwife led trials, and 35 peer-reviewed publications were identified. Publications were of moderate to high quality with scores limited due to an inability to blind participants or clinicians. Blinding of assessors was included in 19 published trials.

DISCUSSION

Additional support for midwives to design and conduct trials and publish findings is required. Further support is needed to translate registration of trial protocols into peer reviewed publications.

CONCLUSION

These findings will inform the Australasian Nursing and Midwifery Clinical Trials Network plans to promote quality midwife led trials.

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

BACKGROUND

management of persistent occiput posterior position has always been controversial. Manual rotation by a delivery operator can reduce instrumental delivery and cesarean section.

AIM

This study aims to determine the knowledge and experience of midwives and gynecologists about manual rotation of persistent occiput posterior position.

METHODS

This 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.

RESULTS

189 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.

CONCLUSION

According 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.

Midwives' views on the acceptability of a future trial of the Sims posture for fetal malposition in labor in the context of their knowledge and practice: A mixed-methods study

INTRODUCTION

Evidence of safe and effective maternal interventions to improve fetal malposition in labor is inconclusive. A contemporary, randomized controlled trial of maternal posture would expand this evidence, however, collaboration with midwives will be critical. The aim of this study is to assess midwives' views on the acceptability of a trial of the Sims posture for fetal malposition in labor and identify current midwifery knowledge and practice surrounding fetal malposition.

METHODS

A mixed-methods study incorporating a web-based survey and guided focus groups with midwives was conducted in New Zealand during 2020. Midwives serving Auckland Hospital and Māori and Pasifika midwives serving South Auckland (n=136) were invited to participate in the study. Data were descriptively analyzed using chi-squared and cross-tabulation. Collaboration with a trial was contextualized by thematic content from survey and focus-group data.

RESULTS

Fifty (36%) midwives from primary and secondary/tertiary settings responded to the survey, and 19 participated in four focus groups. Most midwives thought maternal posture affects malposition, utilize changes of posture often with the peanut ball, would recommend a posture if cesareans were reduced by 20%, and would definitely or probably collaborate with a labor trial of posture. Fetal monitoring with women in the Sims posture was difficult for nearly one-fifth of midwives. Seven themes emerged regarding trial participation: trial design, relevance, practice, diagnosis, knowledge and skills, and trial compliance.

CONCLUSIONS

Current practice concerning malposition utilizes flexibility of posture. Provision of some free movement and reassurance surrounding trial equipoise may enhance trial collaboration.

Obstetric Perineal Tears in Pregnant Adolescents and the Influencing Factors

STUDY OBJECTIVE

The incidence and risk factors of obstetric perineal tear occurrence in vaginal delivery of adolescent pregnant patients are not well established. We aimed to describe the incidence of obstetric perineal tears in adolescents and the maternal obstetric risk factors associated with this situation.

DESIGN

Retrospective cohort study SETTING: Department of Obstetrics and Gynecology, Tepecik Education and Research Hospital, Izmir, Turkey PARTICIPANTS: Adolescent pregnant patients (≤19 years) who delivered vaginally in our institution between January 2014 and January 2021 INTERVENTIONS AND MAIN OUTCOME MEASURES: The main outcome measures were the incidence of perineal tears, the degree of perineal tears, and the risk factors associated with severe perineal tears in adolescents. Severe perineal tears include third- and fourth-degree lacerations. A third-degree tear is defined as partial or complete disruption of the anal sphincter muscles, and a fourth-degree tear is defined as lacerations involving the rectal mucosa.

RESULTS

A total of 3441 adolescents who had a vaginal delivery were included in the study. The rate of severe perineal tear was 5.8% (200/3441). Risk factors associated with obstetric laceration in adolescents in multivariate analysis were nulliparity (OR = 1.72; 95% CI, 1.14-2.41; P = 0.007), high birth weight (OR = 4.1; 95% CI, 2.71-6.21; P < 0.001), and labor induction (OR = 1.36; 95% CI, 1.01-1.85; P = 0.02). Spontaneous onset of labor and previous delivery reduced the risk of severe perineal tear in adolescent pregnant patients (respectively, OR = 0.68; 95% CI, 0.51-0.94; P = 0.02 and OR = 0.51; 95% CI, 0.33-0.79; P = 0.007).

CONCLUSIONS

In adolescents, the risk of severe perineal tear was associated with nulliparity, birth weight, and labor induction. The only possible modifiable risk factor was labor induction.

Manual rotation of occiput posterior or transverse positions: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The primary objective of this systematic review was to assess the association between spontaneous vaginal delivery and manual rotation during labor for occiput posterior or transverse positions. Our secondary objective was to assess maternal and neonatal outcomes.

DATA SOURCES

An electronic search of PubMed, EMBASE, ClinicalTrials.gov, and the Cochrane Register of Controlled Trials covered the period from January 2000 to September 2021, without language restrictions.

STUDY ELIGIBILITY CRITERIA

The eligibility criteria included all randomized trials with singleton pregnancies at ≥37 weeks of gestation comparing the manual rotation groups with the control groups. The primary outcome was the rate of spontaneous vaginal delivery. Additional secondary outcomes were rate of occiput posterior position at delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, obstetrical anal sphincter injury, prolonged second stage of labor, shoulder dystocia, neonatal acidosis, and phototherapy. Subgroup analyses were performed according to types of position (occiput posterior or occiput transverse), techniques used (whole-hand or digital rotation), and parity (nulliparous or parous).

METHODS

The quality of each study was evaluated with the revised Cochrane risk-of-bias tool for randomized trials, known as RoB 2. The meta-analysis used random-effects models depending on their heterogeneity, and risks ratios were calculated for dichotomous outcomes.

RESULTS

Here, 7 of 384 studies met the inclusion criteria and were selected. They included 1402 women: 704 in the manual rotation groups and 698 in the control groups. Manual rotation was associated with a higher rate of spontaneous vaginal delivery: 64.9% vs 59.5% (risk ratio, 1.09; 95% confidence interval, 1.03-1.16; P=.005; 95% prediction interval, 0.90-1.32). This association was no longer significant after stratification by parity or technique used. Manual rotation was associated with spontaneous vaginal delivery only for the occiput posterior position (risk ratio, 1.08; 95% confidence interval, 1.01-1.15). Furthermore, it was associated with a reduction in occiput posterior or transverse positions at delivery (risk ratio, 0.64; 95% confidence interval, 0.48-0.87) and episiotomies (risk ratio, 0.84; 95% confidence interval, 0.71-0.98). The groups did not differ significantly for cesarean deliveries, operative vaginal deliveries, or neonatal outcomes.

CONCLUSION

Manual rotation increased the rate of spontaneous vaginal delivery.

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

OBJECTIVE

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.

METHODS

This was a prospective cohort study conducted in two French tertiary care units. All women with a singleton pregnancy after 37 weeks 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.

RESULTS

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.

CONCLUSION

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.

There are 4, not 7, cardinal movements in labor

The mechanics of labor describe the forces required for fetal descent, and the movements that the fetus must perform to overcome the resistance met by the maternal bony pelvis and soft tissue. The fetus negotiates the birth canal and rotational movements are necessary for descent. Anglo-American literature lists 7 cardinal movements, namely engagement, descent, flexion, internal rotation, extension, external rotation, and expulsion. German and older English literature lists only 4 rotational movements as the cardinal movements and excludes engagement, descent, and expulsion. We would argue that descent is the main purpose of the uterine powers and cardinal movements, a description of the rotational movements the fetal head and shoulders must perform to obtain descent. Ultrasound offers a historically unique opportunity for noninvasive, dynamic studies of the mechanics of labor. The information gathered by clinical examination and ultrasound should be integrated into clinical decision making.

Intrapartum ultrasound and the choice between assisted vaginal and cesarean delivery

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