Sonographic knowledge of occiput position to decrease failed operative vaginal delivery: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: This study aimed to assess the efficacy of sonographic assessment of fetal occiput position before operative vaginal delivery to decrease the number of failed operative vaginal deliveries. DATA SOURCES: The search was conducted in MEDLINE, Embase, Web of Science, Scopus, ClinicalTrial.gov, Ovid, and Cochrane Library as electronic databases from the inception of each database to April 2021. No restrictions for language or geographic location were applied. STUDY ELIGIBILITY CRITERIA: Selection criteria included randomized controlled trails of pregnant women randomized to either sonographic or clinical digital diagnosis of fetal occiput position during the second stage of labor before operative vaginal delivery. METHODS: The primary outcome was failed operative vaginal delivery, defined as a failed fetal operative vaginal delivery (vacuum or forceps) extraction requiring a cesarean delivery or forceps after failed vacuum. The summary measures were reported as relative risks or as mean differences with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) >0% was used to identify heterogeneity. RESULTS: A total of 4 randomized controlled trials including 1007 women with singleton, term, cephalic fetuses randomized to either the sonographic (n=484) or clinical digital (n=523) diagnosis of occiput position during the second stage of labor before operative vaginal delivery were included. Before operative vaginal delivery, fetal occiput position was diagnosed as anterior in 63.5% of the sonographic diagnosis group vs 69.5% in the clinical digital diagnosis group (P=.04). There was no significant difference in the rate of failed operative vaginal deliveries between the sonographic and clinical diagnosis of occiput position groups (9.9% vs 8.2%; relative risk, 1.14; 95% confidence interval, 0.77-1.68). Women randomized to sonographic diagnosis of occiput position had a significantly lower rate of occiput position discordance between the evaluation before operative vaginal delivery and the at birth evaluation when compared with those randomized to the clinical diagnosis group (2.3% vs 17.7%; relative risk, 0.16; 95% confidence interval, 0.04-0.74; P=.02). There were no significant differences in any of the other secondary obstetrical and perinatal outcomes assessed. CONCLUSION: Sonographic knowledge of occiput position before operative vaginal delivery does not seem to have an effect on the incidence of failed operative vaginal deliveries despite better sonographic accuracy in the occiput position diagnosis when compared with clinical assessment. Future studies should evaluate how a more accurate sonographic diagnosis of occiput position or other parameters can lead to a safer and more effective operative vaginal delivery technique.

Intrapartum ultrasound measurement of angle of progression at the onset of the second stage of labor for prediction of spontaneous vaginal delivery in term singleton pregnancies: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to investigate the diagnostic performance of transperineal ultrasound-measured angles of progression at the onset of the second stage of labor for the prediction of spontaneous vaginal delivery in singleton term pregnancies with cephalic presentation. DATA SOURCES: We performed a predefined systematic search in PubMed, Embase, Scopus, Web of Science, and Google Scholar from inception to February 5, 2021. STUDY ELIGIBILITY CRITERIA: Prospective cohort studies that evaluated the diagnostic performance of transperineal ultrasound-measured angles of progression (index test) at the onset of the second stage of labor (ie, when complete cervical dilation is diagnosed) for the prediction of spontaneous vaginal delivery (reference standard) were eligible for inclusion. Eligible studies were limited to those published as full-text articles in the English language and those that included only parturients with a singleton healthy fetus at term with cephalic presentation. STUDY APPRAISAL AND SYNTHESIS METHODS: Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary receiver operating characteristic curves, pooled sensitivities and specificities, area under the curve, and summary likelihood ratios were calculated using the Stata software. Subgroup analyses were done based on angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°. RESULTS: A total of 8 studies reporting on 887 pregnancies were included. Summary estimates of the sensitivity and specificity of transperineal ultrasound-measured angle of progression at the onset of the second stage of labor for predicting spontaneous vaginal delivery were 94% (95% confidence interval, 88%-97%) and 47% (95% confidence interval, 18%-78%), respectively, for an angle of progression of 108° to 119°, 81% (95% confidence interval, 70%-89%) and 73% (95% confidence interval, 57%-85%), respectively, for an angle of progression of 120° to 140°, and 66% (95% confidence interval, 56%-74%) and 82% (95% confidence interval, 66%-92%), respectively, for an angle of progression of 141° to 153°. Likelihood ratio syntheses gave overall positive likelihood ratios of 1.8 (95% confidence interval, 1-3.3), 3 (95% confidence interval, 2-4.7), and 3.7 (95% confidence interval, 1.7-8.1) and negative likelihood ratios of 0.13 (95% confidence interval, 0.07-0.22), 0.26 (95% confidence interval, 0.18-0.38), and 0.42 (95% confidence interval, 0.29-0.60) for angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°, respectively. CONCLUSION: Angle of progression measured by transperineal ultrasound at the onset of the second stage of labor may predict spontaneous vaginal delivery in singleton, term, cephalic presenting pregnancies and has the potential to be used along with physical examinations and other clinical factors in the management of labor and delivery.

A prenatal standard for fetal weight improves the prenatal diagnosis of small for gestational age fetuses in pregnancies at increased risk.

OBJECTIVE: Our aim was to assess diagnostic accuracy in the prediction of small for gestational age (SGA <10th centile) and fetal growth restricted (FGR) (SGA <3rd centile) fetuses using three different sonographic methods in pregnancies at increased risk of fetal growth restriction: 1) fetal abdominal circumference (AC) z-scores, 2) estimated fetal weight (EFW) z-scores according to postnatal reference standard; 3) EFW z-scores according to a prenatal reference standard. METHODS: Singleton pregnancies at increased risk of fetal growth restriction seen in two university hospitals between 2014 and 2015 were studied retrospectively. EFW was calculated using formulas proposed by the INTERGROWTH-21st project and Hadlock; data derived from publications by the INTEGROWTH-twenty-first century project and Hadlock were used to calculate z-scores (AC and EFW). The accuracy of different methods was calculated and compared. RESULTS: The study group included 406 patients. Prenatal standard EFW z-scores derived from INTERGROWTH-21st project and Hadlock and co-workers performed similarly and were more accurate in identifying SGA infants than using AC z-scores or a postnatal reference standard. The subgroups analysis demonstrated that EFW prenatal standard was more or similarly accurate compared to other methods across all subgroups, defined by gestational age and birth weight. CONCLUSIONS: Prenatal standard EFW z-scores derived from either INTERGROWTH-21 st project or Hadlock and co-workers publications demonstrated a statistically significant advantage over other biometric methods in the diagnosis of SGA fetuses.

Brain death in pregnancy: a systematic review focusing on perinatal outcomes.

OBJECTIVE: Brain death (BD) during pregnancy might justify in select cases maternal somatic support to obtain fetal viability and maximize perinatal outcome. This study is a systematic review of the literature on cases of brain death in pregnancy with attempt to prolong pregnancy to assess perinatal outcomes. DATA SOURCES: We performed a systematic review of the literature using Ovid MEDLINE, Scopus, PubMed (including Cochrane database), and CINHAIL from inception to April 2020. STUDY ELIGIBILITY CRITERIA: Relevant articles describing any case report of maternal brain death were identified from the aforementioned databases without any time, language, or study limitations. Studies were deemed eligible for inclusion if they described at least 1 case of maternal brain death. METHODS: Only cases of brain death in pregnancy with maternal somatic support aimed at maximizing perinatal outcome were included. Maternal management strategy, diagnosis, clinical course, fetal monitoring, delivery, and fetal and neonatal outcome data were collected. Mean, range, standard deviation, and percentage calculations were used as applicable. RESULTS: After exclusion, 35 cases of brain death in pregnancy were analyzed. The mean gestational age at diagnosis of brain death was at 20.2±5.3 weeks, and most cases (68%) were associated with maternal intracranial hemorrhage, subarachnoid hemorrhage, and hematoma. The most common maternal complications during the study were infections (69%) (eg, pneumonia, urinary tract infection, sepsis), circulatory instability (63%), diabetes insipidus (56%), thermal variability (41%), and panhypopituitarism (34%). The most common indications for delivery were maternal cardiocirculatory instability (38%) and nonreassuring fetal testing (35%). The mean gestational age at delivery was 27.2±4.7 weeks and differed depending on the gestational age at diagnosis of brain death. Most deliveries (89%) were via cesarean delivery. There were 8 cases (23%) of intrauterine fetal demise in the second trimester of pregnancy (14-25 weeks), and 27 neonates (77%) were born alive. Of the 35 cases of brain in pregnancy, 8 neonates (23%) were described as "healthy" at birth, 15 neonates (43%) had normal longer-term follow-up (>1 month to 8 years; mean, 20.3 months), 2 neonates (6%) had neurologic sequelae (born at 23 and 24 weeks of gestation), and 2 neonates (6%) died (born at 25 and 27 weeks of gestation). Mean birth weight was 1,229 grams, and small for gestational age was present in 17% of neonates. The rate of live birth differed by gestational age at diagnosis of brain death: 50% at <14 weeks, 54.5% at 14 to 19 6/7 weeks, 91.7% at 20 to 23 6/7 weeks, 100% at 24 to 27 6/7 weeks, and 100% at 28 to 31 6/7 weeks. CONCLUSION: In 35 cases of brain death in pregnancy at a mean gestation age of 20 weeks, maternal somatic support aimed at maximizing perinatal outcome lasted for about 7 weeks, with 77% of neonates being born alive and 85% of these infants having a normal outcome at 20 months of life. The data of this study will be helpful in counseling families and practitioners faced with such rare and complex cases.

Delayed versus immediate pushing in the second stage of labor in women with neuraxial analgesia: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The aim of this systematic review and meta-analysis of randomized controlled trials was to evaluate the effect of delayed versus immediate pushing in the second stage of labor on mode of delivery and other outcomes in women with neuraxial analgesia. DATA SOURCES: The research was conducted using MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and the Cochrane Library as electronic databases, from the inception of each database to August 2019. No restrictions for language or geographic location were applied. STUDY ELIGIBILITY CRITERIA: Selection criteria included only randomized controlled trials in pregnant women randomized to either delayed or immediate pushing during the second stage of labor. STUDY APPRAISAL AND SYNTHESIS METHODS: The primary outcome was mode of delivery. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) value of greater than 0% was used to identify heterogeneity. RESULTS: Twelve randomized controlled trials, including 5445 women with neuraxial analgesia randomized to delayed versus immediate pushing during the second stage of labor, were included in the meta-analysis. Of the 5445 women included in the meta-analysis, 2754 were randomized to the delayed pushing group and 2691 to the immediate pushing group. No significant difference between delayed and immediate pushing was found for spontaneous vaginal delivery (80.9% versus 78.3%; relative risk, 1.05; 95% confidence interval, 1.00-1.10; 12 randomized controlled trials, 5540 women), operative vaginal delivery (12.8% versus 14.6%; relative risk, 0.89; 95% confidence interval, 0.75-1.08; 11 randomized controlled trials, 5395 women), and cesarean delivery (6.9% versus 7.9%; relative risk, 0.89; 95% confidence interval, 0.73-1.07; 11 randomized controlled trials; 5395 women). Women randomized to the delayed pushing group had a significantly shorter length of active pushing (mean difference, -27.54 minutes; 95% confidence interval, -43.04 to -12.04; 7 randomized controlled trials, 4737 women) at the expense of a significantly longer overall duration of the second stage of labor (mean difference, 46.17 minutes; 95% confidence interval, 32.63-59.71; 8 studies; 4890 women). The incidence of chorioamnionitis (9.1% versus 6.6%; relative risk, 1.37, 95% confidence interval, 1.04-1.81; 1 randomized controlled trial, 2404 women) and low umbilical cord pH (2.7% versus 1.3%; relative risk, 2.00; 95% confidence interval, 1.30-3.07; 5 randomized controlled trials, 4549 women) were significantly higher in the delayed pushing group. CONCLUSION: In women with spontaneous or induced labor at term with neuraxial analgesia, delayed pushing in the second stage does not affect the mode of delivery, although it reduces the time of active pushing at the expense of a longer second stage. This prolongation of labor was associated with a higher incidence of chorioamnionitis and low umbilical cord pH. Based on these findings, delayed pushing cannot be routinely advocated for the management of the second stage.

Pregnancy in a woman with sacral agenesis from prenatal counseling to delivery: A case report.

Sacral agenesis or CRS (caudal regression syndrome) is a rare congenital condition involving approximately 1 in 25 000 live births (Sharma et al., 2015) and leading to the absence of lower sacral vertebral bodies and severe malformations of the pelvis. This condition is associated with an extreme reduction of the xipho-pubic distance and of the pelvic dimensions. It is reasonable to think that this might lead to an increased difficulty in obtaining a spontaneous pregnancy and to a consistently increased risk of maternal and perinatal complications. In literature, very little is known about pregnancy in patients with sacral agenesis and therefore on the appropriate way to counsel a patient with this condition who is trying to get pregnant (Greenwell et al., 2013). Although a case of pregnancy in a woman with sacral agenesis is mentioned in a book (J. Rogers, 2006) no cases of women with CRS carrying a pregnancy until a viable age for the fetus are reported in medical literature: as far as we know this is the first case reported in literature of a woman with this condition followed before and throughout the pregnancy with reported pre- and perinatal management, leading to a near-term pregnancy. This case could be useful for clinicians who are requested to counsel female patients with the same condition on the possibility of a pregnancy and possible outcomes.

Risk of Fetal Loss in Pregnancies Undergoing Midtrimester Amniocentesis after Inconclusive Chorionic Villus Sampling.

OBJECTIVE: To estimate the procedure-related risk of miscarriage in pregnancies undergoing amniocentesis (AC) following inconclusive results for a chorionic villus sampling (CVS). METHODS: This was a multicentric retrospective cohort study of patients in which both CVS at 11-13 weeks' gestation and AC at 16-22 weeks were performed between January 1st, 2008, and July 31st, 2017. The primary outcome measure was pregnancy loss prior to 24 weeks gestation; the secondary one was intrauterine demise after 24 weeks. RESULTS: A total of 287 patients underwent transabdominal CVS and AC. Nine patients were lost at follow-up; therefore, the analysis was conducted on a population of 278 patients (275 singletons and 3 dichorionic twin pregnancies). AC was performed because of placental mosaicism (93.6%), failure of direct/semidirect preparation of trophoblastic cells (3.2%), or targeted genetic testing after the diagnosis of an anomaly in the second trimester (3.2%). In continuing pregnancies, there were no fetal losses prior to 24 weeks' gestation. Two intrauterine demises (including 1 fetus with multiple anomalies and growth restriction) in the third trimester were recorded. CONCLUSION: Patients undergoing midtrimester AC because of an inconclusive result of CVS can be reasonably reassured that in general the risk of miscarriage and fetal loss following the procedure is very small.

Real-Time Volume Contrast Imaging in the A Plane with a Four-Dimensional Electronic Probe Facilitates the Evaluation of Fetal Extremities in Midtrimester Sonograms.

OBJECTIVE: To evaluate the efficiency of real-time volume contrast imaging in the A plane (VCI-A) of fetal extremities, compared with conventional two-dimensional ultrasound (2D). METHODS: This was a randomized controlled trial of 100 patients undergoing midtrimester sonography. The fetal limbs were imaged with either 2D or VCI-A with a four-dimensional (4D) electronic probe. Time required for the examination, number of images stored, and quality of the documentation were compared. During the study, 6 fetuses with abnormal extremities were scanned with both 2D and VCI-A, and the diagnostic accuracy and quality of the images were also compared. RESULTS: In the VCI-A group, the fetal extremities were imaged more rapidly (2.3 ± 1.1 vs. 3.3 ± 0.9 min, p < 0.0001), less images were required to document the examination (5.6 ± 1.4 vs. 7.3 ± 1.6), and an optimal documentation was more frequently obtained (84 vs. 54%, p < 0.0001) compared with the 2D group. In malformed fetuses, a precise diagnosis was achieved with both techniques, although images obtained with VCI-A were found to be of superior quality. CONCLUSIONS: Real-time VCI-A with a 4D electronic probe is an effective tool for imaging the fetal extremities in midtrimester examinations and carries some advantages over conventional 2D sonography.

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.

Intrapartum Ultrasound to Differentiate Flexion and Deflexion in Occipitoposterior Rotation.

OBJECTIVE: To evaluate the ability of intrapartum ultrasound to differentiate occipitoposterior (OP) rotation with normal flexion of the head from deflexion, to compare the accuracy of ultrasound with the digital examination, and to assess the outcome of labor according to the type of presentation. PATIENTS AND METHODS: A retrospective study of patients with abnormal labor because of either prolongation and/or abnormal cardiotocography and OP rotation who underwent intrapartum sonography. RESULTS: Normal flexion was inferred in 36/42 cases by a longitudinal sonographic view of the fetal face demonstrating the chin approaching the chest. In the remaining 6, deflexion was diagnosed by visualizing the chin separate and distant from the chest. In 3 of these cases, the orbits were at the same level of the pubis suggesting brow presentation. In the remaining 3 cases, the orbits were above the pubis, and sinciput presentation was inferred. Head deflexion was diagnosed more accurately with ultrasound than clinically and always required a cesarean section versus 36% of cases with OP flexed presentation (p = 0.0052). CONCLUSIONS: Fetuses with abnormal labor and OP rotation had deflexed presentations in 14% of cases and were never delivered vaginally. Sonography was far more accurate than the digital examination.

Diagnosis of Severe Fetomaternal Hemorrhage with Fetal Cerebral Doppler: Case Series and Systematic Review.

OBJECTIVES: To analyze the role of middle cerebral artery (MCA) peak systolic velocity (PSV) in the prediction of severe fetomaternal hemorrhage (FMH) and to compare it with standard biophysical assessment. DATA SOURCES: Retrospective review of cases of FMH seen in our unit and systematic review of the literature. RESULTS: We followed the MOOSE guidelines to review the literature. From 838 articles, 16 were selected. In total, 35 women, including 3 cases from our center and 32 obtained from the literature search were included. Diagnosis of FMH was always confirmed by laboratory tests. Patients were seen at 31 ± 5 weeks' gestation (range 16-39) and the most frequent indication for referral was decreased perception of fetal movements. Cardiotocography (CTG) upon admission was sinusoidal in 18 cases, nonreactive in 6, decelerative in 2 and tachycardic in one. MCA-PSV was abnormal in all cases but one. There were 2 perinatal deaths. The mean hemoglobin concentration at birth or at intrauterine transfusion was 4.8 ± 1.9 g/dl. DISCUSSION: The most accurate predictor of FMH was fetal MCA-PSV. CTG was always abnormal but the pattern was frequently nonspecific. We suggest including fetal cerebral Doppler in the evaluation of patients with decreased fetal movements, particularly in those cases with ambiguous results of biophysical testing.

Clinical Validation of the INTERGROWTH-21st Standards of Fetal Abdominal Circumference for the Prediction of Small-for-Gestational-Age Neonates in Italy.

OBJECTIVES: To compare the accuracy of the INTERGROWTH-21st (IG-21) with the Italian Society of Ultrasound in Obstetrics and Gynecology (SIEOG) abdominal circumference (AC) standards in the detection of small-for-gestational-age (SGA) fetuses in a high-risk population. MATERIAL AND METHODS: Our study included all pregnant patients with an increased risk of placental insufficiency that were seen in two Italian university hospitals between 2014 and 2015. The accuracy of IG-21 and SIEOG AC standards in the detection of SGA neonates was analyzed by means of the area under the receiver operating characteristic curve (ROC-AUC) at 4 gestational age intervals (24-27, 28-31, 32-35, >35 weeks). RESULTS: We enrolled 428 patients (278 Italians). There was no significant difference between the ROC-AUC of AC according to IG-21 and SIEOG standards for all birthweight thresholds and gestational intervals that were considered. The diagnostic performance was similar in Italian and non-Italian patients. The accuracy was, however, limited, with values of ROC-AUC ranging between 0.80 and 0.89. CONCLUSIONS: The IG-21 and SIEOG AC standards are interchangeable for the diagnosis of SGA fetuses. The diagnostic accuracy is, however, limited. We provide figures that can be used to stratify the probability that an infant will be SGA in an obstetric population at increased risk of growth restriction.

Automated Measurement of the Angle of Progression in Labor: A Feasibility and Reliability Study.

OBJECTIVES: The aim of this paper was to assess the feasibility and reliability of a new automated method for the measurement of the angle of progression (AoP) in labor. METHODS: AoP was assessed using two-dimensional transperineal ultrasound by two operators in 52 women in active labor to evaluate intra- and interobserver reproducibility. The intermethod agreement between automated and manual techniques was analyzed by means of the intraclass correlation coefficient and Bland-Altman method. RESULTS: Automated measurements were feasible in all cases. Automated assessments correctly depicted the pubic symphysis and fetal head in 133 (85.3%) out of 156 on first assessments and in all 156 after repeating measurements once in case of incorrect first evaluation. The automated technique showed good intra- and interobserver reproducibility and very good agreement with the manual technique. AoP measured by the automated method were significantly wider than those done by the manual technique (119 ± 20° vs. 130 ± 20°, p = 0.005). CONCLUSIONS: Automated assessment AoP is feasible and reproducible. However, measurements performed by the automated software are significantly different from those resulting from the previously published manual technique. In the light of our data, the automated technique does not seem ready yet for clinical use, and the AoP should be exclusively measured by the previously suggested manual technique.

The "occiput-spine angle": a new sonographic index of fetal head deflexion during the first stage of labor.

BACKGROUND: Fetal head "attitude" (relationship of fetal head to spine) in the first stage of labor may have a substantial impact on labor outcome. The diagnosis of fetal head deflexion traditionally is based on digital examination in labor, although the use of ultrasound to support clinical diagnosis has been recently reported. OBJECTIVES: The aims of this study were: (1) to quantify the degree of fetal head deflection via the use of sonography during the first stage of labor; and (2) to determine whether a parameter derived from ultrasound examination (the occiput-spine angle) has a relationship with the course and outcome of labor. STUDY DESIGN: This was a prospective multicentric, cross-sectional study conducted at the Maternity Unit of the University of Bologna and Parma from January 2014 to April 2015. A nonconsecutive series of women with uncomplicated singleton pregnancies at term gestation (37 weeks or more) were submitted to transabdominal ultrasound during the first stage of labor. If fetal position was occiput anterior or transverse, the angle between the fetal occiput and the cervical spine (the occiput-spine angle) was sonographically obtained on the sagittal plane. The measurements of the occiput spine-angle were performed offline by 2 operators who were blinded to the labor outcome. The intra- and interobserver reproducibility and the correlation between the occiput-spine angle and the mode of delivery were evaluated. RESULTS: A total of 108 pregnant women were recruited, 79 of which underwent a spontaneous vaginal delivery and 29 were submitted to obstetric intervention (19 cesarean delivery and 10 instrumental vaginal deliveries). The mean value of the occiput-spine angle measured in the active phase of the first stage was 126° ± 9.8° (SD). The occiput-spine angle measurement showed a very good intraobserver (r = 0.86; 95% confidence interval [95% CI] 0.80-0.90) and a fair-to-good interobserver (r = 0.64; 95% CI 0.51-0.74) agreement. The occiput-spine angle was significantly narrower in women who underwent obstetric intervention (cesarean or vacuum delivery) due to labor arrest (121° ± 10.5° vs 127° ± 9.4°, P = .03). Multivariable logistic regression analysis showed that narrow occiput-spine angle values (OR 1.08; 95% CI 1.00-1.16; P = .04) and nulliparity (OR 16.06; 95% CI 1.71-150.65; P = .02) were independent risk factors for operative delivery. A larger occiput-spine angle width (i.e., >125°) showed to be significantly associated with a shorter duration of labor (hazard ratio = 1.62; 95% CI 1.07-2.45; P = .02). CONCLUSION: We described herein the "occiput-spine angle," a new sonographic parameter to assess fetal head deflection during labor. Fetuses with smaller occiput-spine angle (<125°) are at increased risk for operative delivery.

Subpubic Arch Angle and Mode of Delivery in Low-Risk Nulliparous Women.

OBJECTIVE: To assess whether subpubic arch angle (SPA) measurement before labor onset can predict labor outcome among low-risk pregnant women. METHODS: 3D ultrasound volume was transperineally acquired from a series of nulliparous women with uncomplicated pregnancy at term before the onset of labor. SPA was measured offline using Oblique View Extended Imaging (OVIX) on each volume performed by an investigator not involved in the clinical management. Labor outcome was prospectively investigated in the whole study group. RESULTS: Overall, 145 women were enrolled in the study. Of these, 83 underwent spontaneous vaginal delivery, whereas obstetric intervention was performed in 62 cases (Cesarean section in 40 and vacuum extraction in 22). The SPA appeared to be significantly narrower in the women submitted to obstetric intervention compared with those undergoing spontaneous vaginal delivery (116.8 ± 10.3° vs. 123.7 ± 9.6°, p < 0.01). At multivariate analysis SPA and maternal age were identified as independent predictors of the mode of delivery. On the other hand, the duration of labor did not show a significant relationship with SPA. CONCLUSIONS: In low-risk nulliparous women at term gestation, SPA measurement obtained by 3D ultrasound before the onset of labor seems to predict the likelihood of an obstetric intervention but not the duration of labor.

Demonstration of the Pericallosal Artery at 11-13 Weeks of Gestation Using 3D Ultrasound.

OBJECTIVE: To assess the sonographic visualization of the pericallosal arteries in normal fetuses at 11-13 weeks of gestation using 3D ultrasound. METHODS: We prospectively enrolled women with a singleton pregnancy undergoing ultrasound at 11-13 weeks of gestation. A 3D volume with high-definition power Doppler was acquired starting from the sagittal view of the fetal head and stored in the spatiotemporal image correlation mode. The images of the pericallosal arteries were assigned a score of 0 (no visualization), 1 (visualization of the origin) or 2 (visualization of the whole course). A follow-up scan was performed in all cases at 20 weeks of gestation to assess the presence of the corpus callosum. RESULTS: 70 patients were included and the pericallosal arteries were sonographically detectable in all cases. Image scores of 1 and 2 were obtained in 8 and 62 cases, respectively. The whole length of the vessel was between 3.5 and 4.5 mm. The vast majority of those with a score of 2 were beyond 12 completed weeks of gestation. All fetuses showed a normal corpus callosum at midtrimester and no abnormal brain findings after birth. CONCLUSIONS: The pericallosal arteries are sonographically visible since the first trimester in 3D ultrasound scans of fetuses found to have a normal corpus callosum at follow-up.

Fetal head-symphysis distance and mode of delivery in the second stage of labor.

OBJECTIVE: To evaluate whether the fetal head-symphysis distance measured by three-dimensional transperineal ultrasound during the active second stage predicts operative delivery. DESIGN: Prospective observational study. SETTING: University hospital, Bologna, Italy. POPULATION: Seventy-one nulliparous women at term in active second stage of labor. METHODS: We acquired a series of sonographic volumes at the beginning of the active second stage (T1) and every 20 min thereafter (T2, T3, T4, T5, T6) until delivery. All volumes were retrospectively analyzed and head-symphysis distance was measured for each acquisition. We compared head-symphysis distance between women with spontaneous vaginal delivery and those with operative delivery. Receiver operator characteristic curves were constructed to estimate the accuracy of head-symphysis distance in the prediction of operative delivery. Logistic regression was used to identify independent variables associated with operative delivery. MAIN OUTCOME MEASURES: Operative delivery (vacuum or cesarean). RESULTS: Of the women included, 81.7% had a spontaneous vaginal delivery and 18.3% underwent operative delivery. Women with spontaneous vaginal delivery had shorter head-symphysis distance than women in the operative delivery group at T1 (p < 0.001), T2 (p < 0.001) and T3 (p = 0.025), whereas no significant differences were recorded thereafter. Receiver operator characteristic curves revealed accuracy values of 81.0%, 87.9% and 77.6% in the prediction of operative delivery at T1, T2 and T3, respectively. At multivariate logistic regression head-symphysis distance and epidural analgesia were the only independent predictors of operative delivery among ultrasonographic, maternal and intrapartum variables. CONCLUSIONS: Ultrasonographic measurement of head-symphysis distance in the second stage of labor can be used to predict operative delivery.

Obstetrical provider preferences for cesarean delivery on maternal request in uncomplicated pregnancies: a systematic review of the literature.

OBJECTIVE: This study aimed to review obstetrical providers' personal preferences for cesarean delivery on maternal request in uncomplicated pregnancies. DATA SOURCES: Searches were performed in Ovid-Medline, Cochrane, Scopus, and CINAHL with terms related to "cesarean," "elective," "scheduled," "maternal request," "physician," "obstetrician," "gynecologist," "midwife," "specialist," and "trainee." There was no limitation placed on the language, year, or location of the studies included in the initial search strategy. STUDY ELIGIBILITY CRITERIA: Articles were included if they focused on providers' personal preference for cesarean delivery on maternal request, if they were written in or translated into English, and if they did not meet any exclusion criteria. METHODS: The primary outcome was the percentage of providers preferring cesarean delivery on maternal request in a hypothetical uncomplicated nulliparous term singleton vertex pregnancy. The secondary outcomes included the percentage of providers preferring cesarean delivery on maternal request for a close family member in a nulliparous term singleton vertex pregnancy and the percentage of providers having a personal history of cesarean delivery on maternal request. RESULTS: Overall, 34 articles were included in the review. The studies were conducted across a range of time and geographic locations. The main providers studied were obstetrician-gynecologists and midwives. In the hypothetical scenario asking their personal delivery preference for a nulliparous term singleton vertex pregnancy, the overall preference rate for cesarean delivery on maternal request among all obstetrical providers was 13.5% (966/7154), specifically 14.3% (894/6250) of obstetrician-gynecologists and 2% (11/574) of midwives; these percentages increased over the last 20 years. In the hypothetical scenario asking their delivery preference for a close family member in a nulliparous term singleton vertex pregnancy, these percentages changed to 28.5% (138/484), 67% (138/206), and 0% (0/278), respectively. The percentage of providers with a personal history of cesarean delivery on maternal request was 20.9% (486/2324) overall, specifically 25.2% (338/1339) of obstetrician-gynecologists and 2% (7/347) of midwives. CONCLUSION: Overall, 14.3% of obstetrician-gynecologists would prefer cesarean delivery on maternal request for themselves in a hypothetical nulliparous term singleton vertex pregnancy, and this percentage has increased over the last 20 years. Moreover, 25.2% of obstetrician-gynecologists have had cesarean delivery on maternal request themselves, and 67% of obstetrician-gynecologists would recommend it for a close family member. Alternatively, ≤2% of midwives have had or would recommend cesarean delivery on maternal request.