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.

Prenatal visualisation of the torcular herophili by means of a Doppler technology highly sensitive for low-velocity flow in the expert assessment of the posterior fossa: a prospective study.

OBJECTIVE: To evaluate the usefulness of a Doppler technology highly sensitive for low-velocity flow in the antenatal imaging of the torcular herophili (TH) in the second trimester of pregnancy. DESIGN: Prospective study. SETTING: Referral Fetal Medicine Unit. POPULATION: Non-consecutive series of singleton pregnancies submitted to antenatal neurosonogram between 20 and 28 weeks of gestation. METHODS: A midsagittal section of the fetal brain was obtained by insonating through the anterior fontanelle, then the MV-Flow™ and LumiFlow™ presets were selected to visualise the TH as the posterior confluence of the superior sagittal sinus and the straight sinus. MAIN OUTCOME MEASURES: Evaluation of the anatomic relationship of the TH with the 'transpalatal line' joining the upper bony palate to the fetal skull. RESULTS: A total of 99 pregnant women were recruited, including one fetus with open spina bifida, one with Dandy-Walker malformation (DWM) and two with Blake's pouch cysts. In normal fetuses, the TH appeared to lie on or just below the 'transpalatal line'. In the cases of Blake's pouch cyst, the position of the TH appeared normal if compared with controls, whereas in DWM a supra-elevated position of the TH in respect of the transpalatal line was demonstrated. Finally, in the fetus with Chiari II malformation the TH was identified below the 'transpalatal plane'. CONCLUSIONS: Prenatal ultrasound visualisation of the TH by means of newly developed Doppler technologies characterised by high sensitivity for low-velocity flow is feasible and allows the indirect evaluation of the insertion of cerebellar tentorium in the second trimester. TWEETABLE ABSTRACT: Prenatal imaging of the torcular herophili using a Doppler technology highly sensitive for low-velocity flow.

Prenatal diagnosis of fetal multiple hemivertebrae: the importance of 3D ultrasound assessment.

We herein present a case of fetal multiple hemivertebrae detected at antenatal sonography. The use of the 3 D technology supported by a new contrast enhancement rendering algorithm (Crystal Vue) has allowed the accurate prenatal classification of the defect, confirmed at follow up, that would have been difficult to define by 2 D only.

ISUOG Practice Guidelines: ultrasound assessment of fetal biometry and growth.

INTRODUCTION These Guidelines aim to describe appropriate assessment of fetal biometry and diagnosis of fetal growth disorders. These disorders consist mainly of fetal growth restriction (FGR), also referred to as intrauterine growth restriction (IUGR) and often associated with small­for­gestational age (SGA), and large­for­gestational age (LGA), which may lead to fetal macrosomia; both have been associated with a variety of adverse maternal and perinatal outcomes. Screening for, and adequate management of, fetal growth abnormalities are essential components of antenatal care, and fetal ultrasound plays a key role in assessment of these conditions. The fetal biometric parameters measured most commonly are biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FL). These biometric measurements can be used to estimate fetal weight (EFW) using various different formulae1. It is important to differentiate between the concept of fetal size at a given timepoint and fetal growth, the latter being a dynamic process, the assessment of which requires at least two ultrasound scans separated in time. Maternal history and symptoms, amniotic fluid assessment and Doppler velocimetry can provide additional information that may be used to identify fetuses at risk of adverse pregnancy outcome. Accurate estimation of gestational age is a prerequisite for determining whether fetal size is appropriate­for­gestational age (AGA). Except for pregnancies arising from assisted reproductive technology, the date of conception cannot be determined precisely. Clinically, most pregnancies are dated by the last menstrual period, though this may sometimes be uncertain or unreliable. Therefore, dating pregnancies by early ultrasound examination at 8­14 weeks, based on measurement of the fetal crown­rump length (CRL), appears to be the most reliable method to establish gestational age. Once the CRL exceeds 84 mm, HC should be used for pregnancy dating2­4. HC, with or without FL, can be used for estimation of gestational age from the mid­trimester if a first­trimester scan is not available and the menstrual history is unreliable. When the expected delivery date has been established by an accurate early scan, subsequent scans should not be used to recalculate the gestational age1. Serial scans can be used to determine if interval growth has been normal. In these Guidelines, we assume that the gestational age is known and has been determined as described above, the pregnancy is singleton and the fetal anatomy is normal. Details of the grades of recommendation used in these Guidelines are given in Appendix 1. Reporting of levels of evidence is not applicable to these Guidelines.

Pautas de ISUOG para la práctica: evaluación ecográfica de la biometría y el crecimiento fetal INTRODUCCIÓN: El objetivo de estas Pautas es describir la evaluación adecuada de la biometría fetal y el diagnóstico de los trastornos del crecimiento fetal. Estos trastornos consisten principalmente en la restricción del crecimiento fetal (RCF), también conocida como restricción del crecimiento intrauterino (RCIU), que a menudo está asociada con un tamaño pequeño para la edad gestacional (PEG) o grande para la edad gestacional (GEG), que pueden dar lugar a la macrosomía fetal; ambos se han asociado con una variedad de resultados maternos y perinatales adversos. La detección y el tratamiento adecuado de las anomalías del crecimiento fetal son componentes esenciales de la atención prenatal, y la ecografía fetal desempeña un papel fundamental en la evaluación de estas afecciones. Los parámetros biométricos fetales medidos con mayor frecuencia son (todas las siglas procedentes del inglés) el diámetro biparietal (BPD), el perímetro cefálico (HC), el perímetro abdominal (AC) y la longitud de la diáfisis del fémur (FL). Estas mediciones biométricas se pueden utilizar para estimar el peso del feto (PEF) mediante fórmulas diferentes1 . Es importante diferenciar entre el concepto de tamaño fetal en un momento dado y el crecimiento fetal en sí, siendo este último un proceso dinámico cuya evaluación requiere al menos dos ecografías separadas en el tiempo. La historia y los síntomas de la madre, la evaluación del líquido amniótico y la velocimetría Doppler pueden proporcionar información adicional que se puede utilizar para identificar los fetos bajo riesgo de resultados adversos del embarazo. La estimación precisa de la edad gestacional es un prerrequisito para determinar si el tamaño del feto es apropiado para la edad gestacional (AEG). Excepto en el caso de los embarazos procedentes de tecnologías de reproducción asistida, la fecha de concepción no se puede determinar con precisión. Clínicamente, la fecha de la mayoría de los embarazos se establece en función del último período menstrual, aunque a veces esto puede ser incierto o poco fiable. Por lo tanto, el fechado de los embarazos mediante ecografía temprana a las 8-14 semanas, mediante la medición de la longitud céfalo-caudal (LCC) fetal, parece ser el método más fiable para establecer la edad gestacional. Una vez que la LCC excede los 84 mm, se debe usar el HC2-4 para establecer la fecha del embarazo. El HC, con o sin FL, se puede utilizar para estimar la edad gestacional a partir de la mitad del primer trimestre si no se dispone de una ecografía del primer trimestre y el historial menstrual no es fiable. Cuando se ha establecido la fecha prevista del parto mediante una exploración temprana precisa, no se deben utilizar exploraciones posteriores para recalcular la edad gestacional1 . Las exploraciones en serie se pueden utilizar para determinar si el intervalo del crecimiento ha sido normal. En estas Pautas se asume que la edad gestacional es conocida y ha sido determinada según lo anterior, que el embarazo es de feto único y que la anatomía fetal es normal. En el Apéndice 1 se detallan los grados de recomendación utilizados en estas Pautas. El informe sobre los niveles de evidencia no es aplicable a estas Pautas.

Cerebroplacental ratio assessment in early labor in uncomplicated term pregnancy and prediction of adverse perinatal outcome: prospective multicenter study.

OBJECTIVE: It has been suggested that the use of Doppler ultrasound in term pregnancies with normal-sized fetuses is able to identify those at high risk of subclinical placental function impairment. The objective of this study was to evaluate the relationship between cerebroplacental ratio (CPR) measured in early labor and perinatal and delivery outcomes in a cohort of uncomplicated singleton term pregnancies. METHODS: This was a prospective multicenter observational study conducted at three tertiary centers between January 2016 and July 2017. Low-risk term pregnancies, defined by the absence of maternal morbidity or pregnancy complication, accompanied by normal ultrasound and clinical screening of fetal growth in the third trimester, with spontaneous onset of labor were included. Umbilical artery (UA) and fetal middle cerebral artery (MCA) Doppler was assessed on admission for early labor. All measurements were performed in between uterine contractions and according to international standards. CPR was computed by dividing MCA pulsatility index by UA pulsatility index and converted into multiples of the median (MoM) in order to adjust for gestational age. Doctors and midwives involved in the clinical management of the women were blinded to the results of the Doppler evaluation. Mode of delivery and perinatal outcome were compared between pregnancies with reduced CPR MoM, defined as CPR MoM within the lowest decile of the study population, and those with normal CPR MoM. Receiver-operating characteristics curve analysis was used to assess the predictive performance of CPR for obstetric intervention due to fetal distress and composite adverse perinatal outcome. RESULTS: Overall, 562 women were included. The rate of obstetric intervention for suspected fetal distress in labor was more than three times higher among cases with reduced CPR MoM compared to those with normal CPR MoM (9/54 (16.7%) vs 28/508 (5.5%); P = 0.004). Furthermore, a significantly higher rate of composite adverse perinatal outcome was found in fetuses with CPR MoM < 10th percentile compared to those with CPR MoM ≥ 10th percentile (6/54 (11.1%) vs 19/508 (3.7%); P = 0.012). CPR had low sensitivity and low positive predictive value for prediction of obstetric intervention due to fetal distress (24.3% and 18.0%, respectively) and composite adverse perinatal outcome (24.0% and 11.1%, respectively). CONCLUSIONS: Data on a wide cohort of low-risk term pregnancies in early labor showed that, while reduced CPR is associated with a higher risk of obstetric intervention due to fetal distress and composite adverse perinatal outcome, it is a poor predictor of adverse perinatal outcome. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Three-dimensional assessment of umbilical vein deviation angle for prediction of liver herniation in left-sided congenital diaphragmatic hernia.

OBJECTIVES: To introduce a new sonographic marker of intrathoracic liver herniation in fetuses with left-sided congenital diaphragmatic hernia (CDH). METHODS: In a consecutive series of fetuses with isolated CDH, an ultrasound volume of the fetal abdomen was acquired. On this volume, offline calculation of the angle formed by the midline of the abdomen (joining the center of the vertebral body to the abdominal insertion of the umbilical cord) and a second line joining the center of the vertebral body to the intra-abdominal convexity of the umbilical vein was carried out to give the umbilical vein deviation angle (UVDA). The UVDA was measured in a group of normal fetuses selected as controls. At follow-up, the presence of liver herniation was investigated in all cases of CDH. UVDA values were compared between the CDH group and controls, and between CDH 'liver-up' vs 'liver-down' cases. A receiver-operating characteristics (ROC) curve was constructed to identify a cut-off value of the UVDA with the highest accuracy in predicting liver herniation in the CDH group. RESULTS: Between 2009 and 2015, 22 cases of left-sided CDH were included in the study group, of which nine cases had liver herniation. Eighty-eight normal fetuses were recruited as controls. The UVDA was significantly higher in the cases vs controls (15.25 ± 7.91° vs 7.68 ± 1.55°; P < 0.0001). Moreover, the UVDA was significantly increased in CDH fetuses with liver-up vs liver-down (21.77 ± 8.79° vs 10.75 ± 2.10°; P < 0.0001). On ROC curve analysis the UVDA showed good prediction of liver herniation (area under the ROC curve, 0.94; P < 0.0001) with the best cut-off of 15.2°, yielding a sensitivity of 89% and a specificity of 100% (P < 0.0001). CONCLUSIONS: In fetuses with CDH, umbilical vein bowing may be quantified by measuring the UVDA using three-dimensional ultrasound. This sonographic marker seems to be an accurate predictor of liver herniation in left-sided CDH. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Sonographic assessment of fetal occiput position during the second stage of labor: how reliable is the transperineal approach?

OBJECTIVE: To compare the accuracy of transperineal (TP) ultrasound with transabdominal (TA) approach in the sonographic assessment of fetal occiput position during the second stage of labour. METHODS: A series of low-risk women at term attending the labour ward of three university hospitals were prospectively recruited for the purpose of this study. During the second stage of labor patients were evaluated first by TP and than by TA ultrasound to determine the fetal position. The occiput position was labelled as DOA (direct occiput anterior), ROA (right occiput anterior), LOA (left occiput anterior), DOP (direct occiput posterior), ROP (right occiput posterior), LOP (left occiput posterior), ROT (right occuput transverse) and LOT (left occiput transverse). The agreement between the two techniques was assessed. RESULTS: Overall 80 patients were recruited in the study group. Ultrasound examination was performed at 21(± 8) minutes from the beginning of the active pushing. The ultrasound findings of the fetal occiput position were recorded. In all cases TA ultrasound confirmed the fetal occiput position as determined at TP approach except in one case of ROA that had been recorded as ROT using TP ultrasound. CONCLUSIONS: Ultrasound TP examination is accurate in the diagnosis of fetal occiput position during the second stage of labor.

Agreement between two- and three-dimensional transperineal ultrasound methods for assessment of fetal head-symphysis distance in active labor.

OBJECTIVES: To assess the intermethod agreement between two-dimensional (2D) and three-dimensional (3D) transperineal ultrasound methods in measuring a new index of fetal head station (the fetal head-symphysis distance (HSD)) in active labor, and to assess potential factors that may affect their agreement. METHODS: HSD was measured by transperineal ultrasound in 86 women in active labor, once using a 2D and once using a 3D technique. 2D images were acquired first in 43 cases and 3D images were acquired first in the other 43 women. Intermethod agreement between 2D and 3D methods was analyzed by means of intraclass correlation coefficient (ICC) and Bland-Altman analysis. In addition, potential factors affecting the intermethod reproducibility were investigated including fetal occiput position, order of acquisition, fetal head station, stage of labor, maternal body mass index and use of epidural analgesia, using the ANOVA test to check for systematic bias and Levene's test for homoscedasticity. RESULTS: Good agreement was demonstrated between 2D and 3D measurements of HSD (ICC, 0.949 (95% CI, 0.914-0.984)). No evidence of systematic difference was shown between the two methods (average difference ± SD = 0.03 ± 2.29 mm; P = 0.888). The only factor that had a significant effect on systematic difference between 2D and 3D methods was order of acquisition (P = 0.042); the first observation was higher regardless of the method used. Fetal head station had a significant effect on the homogeneity between the two methods (P = 0.004) with a better 2D-3D agreement obtained at lower head stations (SD of differences: 1.63 vs 2.59 mm). CONCLUSIONS: There is very good agreement between 2D and 3D methods of assessing HSD. Agreement is better in lower fetal head stations.

Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery.

OBJECTIVE: To compare longitudinal changes in angle of progression (AoP) and midline angle (MLA) during the active second stage of labor according to the mode of delivery. METHODS: A three-dimensional transperineal ultrasound volume was acquired in a series of nulliparous women at the beginning of the active second stage (T1) and every 20 min thereafter (T2, T3, T4, T5 and T6). Following delivery, all ultrasound volumes were analyzed and AoP and MLA were measured. RESULTS: Among 71 women included in the study, 58 underwent spontaneous vaginal delivery (group A) and 13 underwent operative delivery (group B) (eight by vacuum extraction and five by Cesarean section). When compared with Group B, Group A had a wider AoP only at T1 (140.0 ± 20.2° vs. 122.9 ± 16.7°; P = 0.010) and T2 (149.7 ± 20.7° vs. 126.9 ± 17.5°; P = 0.006). MLA was narrower in group A only at T3 (21.2 ± 11.7° vs. 40.8 ± 27.9°; P = 0.043), T4 (18.2 ± 15.0° vs. 47.4 ± 29.6°; P = 0.020) and T5 (18.3 ± 6.0° vs. 34.7 ± 4.2°; P = 0.034). On stepwise forward multiple logistic regression analysis, both AoP and MLA were independently associated with operative delivery (OR = 0.955 and OR = 1.018, respectively). CONCLUSION: Ultrasonographic assessment of fetal head descent in the second stage of labor may play a role in the prediction of the mode of delivery.