Sonographic evaluation of the fetal spine position and success rate of manual rotation of the fetus in occiput posterior position: A randomized controlled trial

Association between Elevated Intrauterine Resting Tone during Labor and Neonatal Morbidity

OBJECTIVE

 Internal contraction monitoring provides a quantitative assessment of intrauterine resting tone. During the course of labor, elevated intrauterine resting tone may be identified. We hypothesized that elevated intrauterine resting tone could lead to compression of the spiral arteries, thus limiting uterine blood flow and resulting in neonatal compromise. Therefore, our objective was to assess the association between elevated resting tone during labor and neonatal morbidity.

STUDY DESIGN

 This was a secondary analysis of a prospective cohort study of singleton deliveries at ≥37 weeks of gestation. Patients with ruptured membranes and an intrauterine pressure catheter in place for at least 30 minutes prior to delivery were included. Intrauterine resting tone was calculated as the average baseline pressure between contractions during the 30 minutes prior to delivery. The study group had elevated intrauterine resting tone, defined as intrauterine resting tone ≥75th percentile (≥12.3 mm Hg). Primary outcome was composite neonatal morbidity: hypoxic-ischemic encephalopathy, hypothermia treatment, intubation, seizures, umbilical arterial pH ≤7.1, oxygen requirement, or death. Secondary outcomes included umbilical artery pH <7.2, lactate ≥4 mmol/L, and rates of neonatal intensive care unit admission.

RESULTS

 Of the 8,580 patients in the cohort, 2,210 (25.8%) met the inclusion criteria. The median intrauterine resting tone was 9.7 mm Hg (interquartile range: 7.3-12.3 mm Hg). Elevated resting tone was associated with a shorter median duration of the first stage of labor (10.0 vs. 11.0 hours, p < 0.01) and lower rates of labor induction and oxytocin augmentation (p < 0.01). Neonatal composite morbidity was higher among patients with elevated intrauterine resting tone (5.1 vs. 2.9%, p = 0.01). After adjusting for chorioamnionitis and amnioinfusion, elevated intrauterine resting tone was associated with increased risk of neonatal morbidity (adjusted odds ratio: 1.70, 95% confidence interval: 1.06-2.74).

CONCLUSION

 Our findings suggest that elevated intrauterine resting tone is associated with increased risk of neonatal composite morbidity.

KEY POINTS

· Higher intrauterine resting tone is associated with increased risk of neonatal morbidity.. · Elevated intrauterine tone can negatively impact umbilical artery pH and lactate levels.. · If elevated intrauterine pressure is noted, we recommend close monitoring of fetal status..

First and Second Stage Labor Management: ACOG Clinical Practice Guideline No. 8

PURPOSE

The purpose of this document is to define labor and labor arrest and provide recommendations for the management of dystocia in the first and second stage of labor and labor arrest.

TARGET POPULATION

Pregnant individuals in the first or second stage of labor.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one maternal-fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes definitions of labor and labor arrest, along with recommendations for the management of dystocia in the first and second stages of labor and labor arrest. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

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.

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

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

Standardized Ultrasound Diagnosis of Nuchal Cord

Objective

This study aims to investigate the formation factors that affect the angle of nuchal cord and explore the types of nuchal cord that exist and the process of standardized ultrasound diagnosis of nuchal cord.

Methods

Ultrasonography was performed on 707 fetuses with nuchal cord, to observe the direction of the coil, determine the type of coil, and analyze the correlation between the fetal position, placental location, and the direction of the coil with the angle of the umbilical cord.

Results

Among the 707 fetuses, those with 1 loop accounted for 89.67%, fetuses with 2 loops accounted for 6.08%, fetuses with 3 loops accounted for 0.28%, and fetuses with partial draping of the umbilical cord accounted for 3.96%. Nuchal cord mostly occurred in fetuses where the placenta was attached to the anterior wall of the uterus, and the α-shaped and C-shaped types were in the majority. The C-shaped type accounted for 43.14%, the α-shaped type for 40.88%, the O-shaped type for 12.02%, and the L-shaped type for 3.96%.

Conclusion

The direction of the coil of the umbilical cord can be determined by blood flow vector observation. The fetal position, placental location, and the direction of the coil are the three factors affecting the coiling angle of the umbilical cord. Ultrasonic classification of nuchal cord can provide detailed information, which can be used by physicians when performing surgery on the fetus. The advances in the diagnosis procedure allow the diagnosis of nuchal cord to be carried out in an orderly manner, making it more accurate and standardized.

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.

Intrapartum ultrasound for the diagnosis of cephalic malpositions and malpresentations

Fetuses with malpresentation and malposition during labor represent important clinical challenges. Women with fetuses presenting with malpresentation or malposition are at risk of increased perinatal complications, such as cesarean delivery, failure of operative vaginal delivery, neonatal acidemia, and neonatal intensive care admission. Intrapartum ultrasound has been found to be more reliable than digital examination in assessing malpresentation and malposition. The use of intrapartum ultrasound to assess fetal position and presentation, in addition to fetal attitude, to predict and aid in decision making regarding delivery can help in improving management decision making. Cephalic malpresentation and malposition is a unique subset of fetal orientation and can benefit from intrapartum ultrasound identification and assessment for delivery.

Normal fetal development of the cervical, thoracic, and lumbar spine: A postmortem study based on magnetic resonance imaging

OBJECTIVE

Before evaluating spinal pathology, it is essential to have knowledge of the normal spinal development at different gestational ages. This study aims to characterize normal spinal growth in human fetuses during the second and third trimesters.

METHODS

Postmortem 3.0 T magnetic resonance imaging (MRI) was performed on 55 fetuses at 17-42 gestational weeks by using three-dimensional T2-weighted sequences. Morphological changes and quantitative measurements of the fetal spine were assessed. The correlation between centrum ossification center volume (COCV) and gestational age was investigated.

RESULTS

The cervical, thoracic, and lumbar COCVs showed a positive relationship with gestational age (p < 0.05). No gender differences were found in the volumetric development of the cervical, thoracic, and lumbar centrum ossification centers (COCs). The average volumetric growth rate per COC was larger in the lumbar spine than in the cervical and thoracic spine. The L1-L5 COCVs also showed a linear positive relationship with gestational age.

CONSULTS

Postmortem 3.0 T MRI clearly demonstrated spinal changes in external contour and internal structure with gestational age. These findings expand our understanding of the early growth pattern of the human spine and could be further used to assess the developmental conditions of the fetal spine.

Digital and Manual Rotation of the Persistent Occiput Posterior Fetus

Persistent fetal occiput posterior (OP) position is a topic of interest with implications for intrapartum management. Although studies report a low incidence of persistent OP position, anecdotal evidence suggests an increase in prevalence given changes in maternal demographics. Clinicians are often familiar with interventions such as position changes and the use of props and a rebozo to address persistent OP position in early labor; however, midwives remain uncomfortable with the techniques of digital and manual rotation. This article reviews current evidence and recommendations for the management of persistent OP position in the second stage of labor. Further research is needed to guide clinicians on the optimal timing and techniques for digital and manual rotation.

Evidence-based management of the second stage of labor

The second stage of labor is defined as the time from complete dilation of the cervix to delivery of the fetus. The objective of this seminar is to provide a contemporary, evidence-based approach to management of the second stage of labor. This seminar reviews background maternal and fetal characteristics that impact the duration of the second stage of labor, the recommended evidence-based management (e.g. immediate pushing, manual rotation, operative vaginal delivery), and the maternal/neonatal morbidity clinicians must consider when deciding between operative delivery and a prolonged second stage of labor.

Standardization of diagnosis for coiling of the umbilical cord around fetal neck by ultrasound

OBJECTIVE

To elucidate classification of coiling of the umbilical cord around fetal neck (CUFN) by ultrasound and forming factors of entanglement angle of CUFN.

METHODS

From January 2006 to December 2012, color Doppler ultrasonic was used to observe the blood flow vector of umbilical artery, and prospective descriptive observation was made for entanglement direction and type of 707 single fetuses taking prenatal examination in our hospital during the middle and late trimester of pregnancy and having umbilical cord echo around the neck. The relationship of position of fetus, position of placenta and entanglement direction of umbilical cord with the entanglement angle of umbilical cord is analyzed.

RESULTS

Among the 707 fetuses, 634 had one circle of coiling, 43 had two circles of coiling, two had three circles of coiling, and 28 had CUFN. According to entanglement direction, 361 had entanglement from left to right and 318 had entanglement from right to left According to entanglement type, 305 were C-shaped type (43.14%), 85 were O-shaped type (12.02%), 289 were α-shaped type (40.88%), and 28 were L-shaped type (3.96%).

CONCLUSION

Color Doppler ultrasound was used to detect the entanglement direction of umbilical cord and establish the five-type classification of umbilical cord around the neck, laying the foundation for the feasibility of establishing the normalization of diagnostic standard of umbilical cord around the neck.

[Manual rotation in occiput posterior position: A systematic review in 2019]

OBJECTIVE

The aim of our study was to evaluate the safety and the benefits of manual rotation in the management of Occiput-posterior positions in 2019.

METHODS

A systematic review of literature was performed using the MEDLINE and COCHRANE LIBRARY databases, in order to identify articles concerning maternal and neonatal outcomes after a manual rotation, through January 2019. Information on study characteristics (review, author, year of publication), population, objectives and main neonatal and maternal outcomes were extracted.

RESULTS

A total of 51 articles were identified and 12 articles were selected for the systematic review. The rate of successful manual rotation were about 47 to 90%. There were more success if systematic manual rotation, multiparity, engagement, spontaneous labour and maternal age<35. The 2nd stage of labour was shorter after an attempt of manual rotation. The randomised controlled trials did not find any statistical difference concerning operative deliveries or neonatal and maternal outcomes.

CONCLUSION

The manual rotation is an obstetrical manoeuvre which must be regulated and only practiced by trained operators. Currently, the state of science is not sufficient to recommend the manual rotation as a systematic practice in 2019.

The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations

Fetal malpositions and cephalic malpresentations are well-recognized causes of failure to progress in labor. They frequently require operative delivery, and are associated with an increased probability of fetal and maternal complications. Traditional obstetrics emphasizes the role of digital examinations, but recent studies demonstrated that this approach is inaccurate and intrapartum ultrasound is far more precise. The objective of this review is to summarize the current body of literature and provide recommendations to identify malpositions and cephalic malpresentations with ultrasound. We propose a systematic approach consisting of a combination of transabdominal and transperineal scans and describe the findings that allow an accurate diagnosis of normal and abnormal position, flexion, and synclitism of the fetal head. The management of malpositions and cephalic malpresentation is currently a matter of debate, and individualized depending on the general clinical picture and expertise of the provider. Intrapartum sonography allows a precise diagnosis and therefore offers the best opportunity to design prospective studies with the aim of establishing evidence-based treatment. The article is accompanied by a video that demonstrates the sonographic technique and findings.