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Objective: We investigated the correlation between the angle of progression measured by transperineal ultrasound and fetal head station measured by open magnetic resonance imaging (MRI), the gold standard, in pregnant women at full term., Methods: Thirty-one pregnant women at full term with a fetus in the occipitoanterior position were enrolled. First, the distance between the leading part of the skull and the interspinal plane was obtained using an open MRI system with the patient in a supine position. Immediately after MRI, the angle of progression was obtained by transperineal ultrasound without changing the woman's posture., Results: There was a significant correlation between the angle of progression determined by transperineal sonography and the distance between the presenting fetal part and the level of the maternal ischial spines (y = - 0.51x + 60.8, r(2) = 0.38, P < 0.001). None of the fetal heads was engaged at the time of MRI and ultrasound examinations., Conclusions: The present study demonstrated a predictable relationship between the angle of progression obtained by transperineal ultrasound and the traditional scale used to quantify fetal head descent. Based on our results, station 0 would correspond to a 120° angle of progression. However, this correlation is based on statistical assumptions only and has to be proven in future studies., (Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.)

Objectives: To assess whether ultrasound experience or fetal head station affects the reliability of measurement of fetal head descent using the angle of progression on intrapartum ultrasound images obtained by a single experienced operator, and to determine reliability of measurements when images were acquired by different operators with variable ultrasound experience., Methods: One experienced obstetrician performed 44 transperineal ultrasound examinations of women at term and in prolonged second stage of labor with the fetus in the occipitoanterior position. Three midwives without ultrasound experience, three obstetricians with < 5 years' experience and three obstetricians with > 10 years' experience measured fetal head descent based on the angle of progression in the images obtained. The angle of progression was measured by two obstetricians in independent ultrasound examinations of 24 laboring women at term with the fetus in the cephalic position to allow assessment of the reliability of image acquisition. Intraclass correlation coefficients (ICCs) with 95% confidence interval (CI) were used to evaluate interobserver reliability and Bland-Altman analysis was used to assess interobserver agreement., Results: In total, 444 measurements were performed and compared. Interobserver reliability with respect to offline image analysis was substantial (overall ICC, 0.72; 95% CI, 0.63-0.81). ICCs were 0.82 (95% CI, 0.70-0.89), 0.81 (95% CI, 0.71-0.88) and 0.61 (95% CI, 0.43-074) for observers with > 10 years', < 5 years' and no ultrasound experience, respectively. There were no significant differences between ICCs among observer groups according to ultrasound experience. Fetal head station did not affect reliability. Bland-Altman analysis indicated reasonable agreement between measurements obtained by two different operators with > 10 years' and < 5 years' ultrasound experience (bias, -1.09 degrees ; 95% limits of agreement, -8.76 to 6.58). The reliability of measurement of the angle of progression following separate image acquisition by two experienced operators was similar to the reliability of offline image analysis (ICC, 0.86; 95% CI, 0.70-0.93)., Conclusions: Measurement of the angle of progression on transperineal ultrasound imaging is reliable regardless of fetal head station or the clinician's level of ultrasound experience.

Objectives: To compare the angle of progression on transperineal ultrasound imaging between different modes of delivery in prolonged second stage of labor with occipitoanterior fetal position., Methods: We prospectively evaluated 41 women at term (>or= 37 weeks) with failure to progress in the second stage of labor. Only cases with occipitoanterior fetal position were included in the final analysis. These cases were classified into three groups: Cesarean section for failure to progress, vacuum extraction for failure to progress, and spontaneous delivery following prolonged second stage of labor. Transperineal ultrasound examination was performed just before digital examination and subsequent delivery. The angle between a line placed through the midline of the pubic symphysis and a line running from the inferior apex of the symphysis tangentially to the fetal skull (the so-called 'angle of progression') was measured offline by an observer blinded to the mode of delivery., Results: There were 26 cases with occipitoanterior fetal position (Cesarean section, n = 5; vacuum extraction, n = 16; spontaneous delivery, n = 5). Logistic regression analysis showed a strong relationship between the angle of progression and the need for Cesarean delivery (R(2) measure of fit = 55%, likelihood ratio chi-square P < 0.0001). When the angle of progression was 120 degrees , the fitted probability of either an easy and successful vacuum extraction or spontaneous vaginal delivery was 90%., Conclusions: This is the first report to document a strong relationship between an objective ultrasound marker (angle of progression) and the mode of delivery following prolonged second stage of labor with occipitoanterior fetal position. A predictive model using this parameter would allow better decision making regarding operative delivery for obstructed labor., ((c) 2009 ISUOG. Published by John Wiley & Sons, Ltd.)

Objective: To describe the course and outcome of fetuses with absent or reversed end-diastolic (ARED) flow in the umbilical artery (UA) and to examine the influence of prematurity according to gestational age at delivery., Methods: Sixty pregnancies complicated by ARED flow in the UA were monitored by repeat Doppler measurements of arterial and venous vessels, non-stress tests (cardiotocogram (CTG)) and maternal investigations, and were delivered between 24 and 34 weeks. Fetal outcome was investigated and compared to a control group of appropriate-for-gestational age (AGA) preterm neonates, matched for gestational age. Mortality, birth weight, Apgar scores, postnatal cord arterial pH and need for ventilation were all recorded, as were cases of respiratory distress syndrome, bronchopulmonary dysplasia, persistent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage, periventricular leukomalacia, abnormal neurological findings and those requiring surgical intervention. Additionally, the group of fetuses with ARED flow was divided into three subgroups of different degrees of prematurity (delivery between 24 + 0 and 28 + 6 weeks, delivery between 29 + 0 and 31 + 6 weeks, and delivery after 32 weeks) and compared according to the above parameters., Results: Pre- or postnatal death occurred in 16 cases. Comparing the 44 (61%) that were born alive with the AGA neonates, significant differences were found in birth weight (P < 0.001), arterial pH value (P < 0.001), bronchopulmonary dysplasia (P = 0.002) and intestinal complications (P < 0.01). Prematurity-related complications were: need for ventilation (P = 0.001), respiratory distress syndrome (P < 0.0001), periventricular leukomalacia (P = 0.002) and pathological neurological testing (P = 0.005)., Conclusions: Neonates displaying ARED flow before birth are growth restricted, acidemic at delivery and are at high risk of developing bronchopulmonary dysplasia and intestinal complications. While perinatal mortality seems to be related to abnormal fetal Doppler velocimetry, age at delivery has a significant impact on short-term morbidity. After 32 weeks, morbidity is low and delivery should be considered. It could be speculated from our data that prolongation of pregnancy with Doppler velocimetry monitoring could help to reduce morbidity, although prolongation remains limited in most cases., (Copyright 2005 ISUOG)

Rhabdoid tumors of the kidney are highly lethal malignancies of infancy. We report the prenatal detection of a renal rhabdoid tumor with mesoblastic components in a fetus at 27 weeks of gestation. The tumor presented as a large mass in the left renal area and there was concomitant massive polyhydramnios. Though the sonographic features alone did not allow distinction from a benign lesion, the aggressive tumor growth indicated malignancy. Amniotic fluid cytology was performed but failed to confirm the diagnosis. Corticosteroids were administered for lung maturation. Tocolysis, including betamimetics, magnesium and indomethacin, was performed to prevent premature labor. Additionally, serial amniodrainage was performed. At 30 weeks of gestation fetal hydrops developed and a Cesarean section was performed. After delivery, ventilation of the preterm infant was insufficient due to diaphragm elevation by the huge tumor, requiring immediate tumor surgery. However, though ventilation was improved the infant died of cardiac failure 4 h after surgery., (Copyright 2004 ISUOG.)

Objectives: This study was designed to compare a conventional multiplanar technique for three-dimensional (3D) ultrasound measurement of fetal lung volume with a rotational method using VOCAL trade mark (Virtual Organ Computer-aided AnaLysis)., Methods: Thirty-two fetuses with a variety of conditions at risk for pulmonary hypoplasia were studied. 3D volume data sets of the fetal lungs were acquired using a commercially available ultrasound system. The right and left lung volumes were calculated separately using VOCAL and the multiplanar technique. The level of agreement between two independent observers in categorizing the 3D volume data set as measurable or non-measurable was determined. The interobserver and intermethod variabilities were also evaluated for both methods., Results: The intermethod variability was excellent (correlation r = 0.93 and r = 0.96 for the left and right lung, respectively), and there was substantial agreement between the results of both approaches (limits of agreement - 4.4 to 8.9 and - 3.4 to 4.8 mL for the right and left lung, respectively). Fetal lung estimation with VOCAL had a significantly higher interobserver variability than the multiplanar technique. Interobserver agreement in categorizing lung volume data sets as measurable or non-measurable was lower when VOCAL was used., Conclusion: Fetal lung volume measurements can be undertaken interchangeably using the multiplanar technique or the rotational method with VOCAL. However, the latter was less reproducible (lower degree of agreement and significantly higher interobserver variability) than the former., (Copyright 2003 ISUOG. Published by John Wiley & Sons, Ltd.)

Objective: Congenital heart defects (CHD), particularly conotruncal anomalies, may be associated with deletion of chromosome 22q11.2. Thymic aplasia or hypoplasia is known to be a typical feature in this condition. We aimed to establish (i) the prevalence of del22q11.2 in fetal CHD and (ii) whether ultrasound assessment of an absent or hypoplastic fetal thymus helps in preselection of a group who are at high risk for this deletion., Study Design: In fetuses (> 16 weeks) with CHD, karyotyping and fluorescence in situ hybridization for 22q11.2 were offered and the fetal thymus was evaluated sonographically., Results: One hundred and forty-nine fetuses with CHD and normal karyotype were analyzed. Seventy-six fetuses had conotruncal anomalies. 22q11.2 deletion was present in 10 cases (6.7%), all of which had conotruncal anomalies (13.1%). Thymic hypoplasia or absence was suspected in 11 cases with conotruncal anomaly. Nine of these 11 had the deletion; two cases were false positive. One fetus with a normal-sized thymus had deletion of 22q11.2 (sensitivity 90%, specificity 98.5%, positive predictive value 81.8%, and negative predictive value 99.2%). By subtype of cardiac anomaly, there was deletion in four of six fetuses with interruption of the aortic arch, two of four with absent pulmonary valve syndrome, three of nine with truncus arteriosus and one of 11 cases of tetralogy of Fallot. Pulmonary atresia with ventricular septal defect (n = 7), right-sided aortic arch (n = 4), transposition of the great arteries (n = 14), double outlet right ventricle (n = 13) and other complex malpositions of the great vessels (n = 8) were not associated with the deletion., Conclusion: Thymic hypoplasia or aplasia may reliably be diagnosed during fetal echocardiography. The technique allows identification of a group at high risk for 22q11.2 deletion and is more specific and sensitive than by subtype of cardiac anomaly alone.

The prenatal sonographic features of a fetus with right-sided congenital diaphragmatic hernia diagnosed at 33 weeks are presented. Color Doppler demonstrated an abnormal course of the right renal artery, arising from the aorta and feeding the intrathoracic right kidney. This case report stresses the role of color Doppler in defining which organs have herniated in fetuses with diaphragmatic hernia.

Objective: To assess the fetal cardiovascular system using three-dimensional power Doppler ultrasound (3D-PDU) in normal and abnormal conditions during the second half of gestation., Subjects: Forty-five normal fetuses and 87 selected pregnancies with different abnormalities involving the vascular system were examined., Methods: The following regions of interest were assessed: placental, umbilical, abdominal, renal, pulmonary and intracranial vessels together with the heart and great arteries. Equipment used was a commercially available HDI-3000 and 5000 ultrasound system with integrated 3D-Color Power Angio software. Data acquisition was performed by the free-hand technique. Images were reconstructed online. In pathological cases, a maximum of three attempts of 3D reconstruction was allowed to obtain the information needed., Results: Satisfactory visualization of the fetal vascular system using 3D-PDU could be achieved in normal pregnancies. The main difficulty during the learning curve was the optimization of the power Doppler image prior to 3D data acquisition. Despite good visualization conditions, the reconstruction of satisfactory images was only possible in 56 out of the 87 (64%) pregnancies with abnormal vascular anatomy. These were abnormalities of placenta and umbilical vessels (n = 26), intra-abdominal and intrathoracic anomalies (n = 12), renal malformations (n = 9), central nervous system (n = 4) and cardiac defects (n = 5). The main reasons for the lack of information were fetal position and movements, overlapping with signals from neighboring vessels as well as technical limitations of the online system. Details and figures of the potential field of interest in prenatal diagnosis are presented.

Objective: The purpose of this investigation was to examine the characteristics of breathing-related fluid flow in the trachea of human fetuses with congenital diaphragmatic hernia in the hopes of developing a standard for the prenatal diagnosis of the degree of severity of the resulting pulmonary hypoplasia. Our ultimate goal is the prediction of postnatal mortality in fetuses with congenital diaphragmatic hernia., Subjects and Methods: The study comprised six cases of isolated congenital diaphragmatic hernia (one on the right side; five on the left) varying in gestational age from 26 to 36 weeks. Four of the patients survived after surgical repair and two died during the neonatal period owing to lung hypoplasia. Color Doppler was used to visualize the fluid displacement in the trachea generated by fetal breathing movements. Spectral Doppler was then used to analyze the fluid flow velocity waveforms. More than 40 continuous breathing cycles (inspiration + expiration) were recorded for each case. We distinguished between regular and irregular patterns., Results: Only the regular breathing phases, defined as five or more consecutive cycles of symmetric appearance, were considered for analysis. The inspiration and expiration times, the peak velocity of inspired and expired fluid and the volume obtained by integration of the tracheal fluid flow displaced during fetal breathing were compared with those of five healthy fetuses for each gestational age. Only the tracheal volume flow was helpful in predicting outcome. In normal pregnancies this parameter increased from 0.21 +/- 0.10 ml/breath (mean +/- SD) at 26 weeks to 1.37 +/- 0.48 ml/breath at 36 weeks of gestation. A significantly low (p < 0.05) volume flow was found only in the fetuses with congenital diaphragmatic hernia with a lethal postnatal outcome, whereas this parameter was normal in all survivors., Conclusions: Our preliminary observations suggest that the tracheal volume flow during fetal breathing activity is related to lung growth. In fetuses with severe lung hypoplasia one would expect a significant reduction in this parameter as an expression of deficient fetal lung growth. The displaced fluid volume per breath in the trachea of human fetuses as assessed by Doppler ultrasound may be a useful predictor of outcome in cases of isolated congenital diaphragmatic hernia.

Prenatal suspicion of esophageal atresia is usually based on the finding of a small or absent fetal stomach in association with polyhydramnios. As similar findings may be generated by other abnormalities, confirmation of the diagnosis is generally not possible until birth. We present a case in which the suspicion of esophageal atresia was raised in the 22nd week of pregnancy in the presence of a small stomach bubble associated with a persistent left superior vena cava. The diagnosis was confirmed 4 weeks later by direct visualization of the fluid-filled blind-ending esophagus during fetal swallowing, which we called the upper neck pouch sign. This is the first case in which the onset of this sonographic entity was specifically observed on serially repeated sonograms as early as the 22nd week. The appearance of this direct sign of esophageal atresia is described, and the literature is reviewed.

Our aim was to determine if it was technically possible to assess fetal tracheal fluid flow during fetal breathing movements, and to compare the data obtained with those recorded in the fetal nasopharynx. Tracheal and nasal fluid flow was analyzed in ten uncomplicated pregnancies, the gestational age ranging between 28 and 38 weeks. Color Doppler was used to detect the fluid displacement in the trachea generated by fetal breathing movements. Spectral Doppler was then used to analyze the fluid flow velocity waveforms. During the same breathing episode, nasal fluid flow was assessed by the same technique. The inspiration and expiration times were variable and not statistically comparable for both nasal and tracheal flow. Peak velocities of inspired and expired fluid were higher in the trachea than in the nose (p < 0.05). We found that the peak velocity of tracheal flow waveforms was significantly higher for inspiration than expiration (p < 0.05). No significant differences were found in the time velocity integral between inspiration and expiration (p = 0.79). The calculated intratracheal flow volume displaced during one breathing cycle increased from 1.3 to 5.0 ml with advancing gestation. Assessment of nasal and tracheal flow, using color and spectral Doppler, is feasible in the human fetus. Intratracheal flow measurements may provide an insight into the effect of fetal breathing movements on lung fluid in the human fetus.