Semi-Automatic Identification of the Fetal Profile and Nasal Bone Measurement at the Time of the Routine Mid-Trimester Ultrasound Scan.

PURPOSE: This study was designed to compare nasal bone length (NBL) measurements using a manual multiplanar mode with those made using a newer semi-automatic technique (Volume NT™) acquired by an experienced operator as well as measurements done by two independent observers with different levels of ultrasound experience (conventional 2 D vs. Volume NT™). MATERIALS AND METHODS: Ultrasound examination was performed prospectively on 81 pregnant women with a singleton pregnancy at the time of their routine mid-trimester ultrasound scan. RESULTS: The correct mid-sagittal plane of the fetal profile was successfully obtained using the semi-automatic technique in 53 of 81 cases. CONCLUSION: NBL measurements using conventional two-dimensional techniques showed significantly higher inter-observer variability than the semi-automatic program. Our study shows the feasibility of using a semi-automatic technique, especially for less experienced operators. Measurements obtained with the semi-automatic technique produced much less variable results around a mean than those obtained with conventional two-dimensional ultrasound.

Relationship between fetal head station established using an open magnetic resonance imaging scanner and the angle of progression determined by transperineal ultrasound.

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.

Measurement of fetal head descent using the 'angle of progression' on transperineal ultrasound imaging is reliable regardless of fetal head station or ultrasound expertise.

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.

Transperineal ultrasound imaging in prolonged second stage of labor with occipitoanterior presenting fetuses: how well does the 'angle of progression' predict the mode of delivery?

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.

Factors for Preterm Births in Germany - An Analysis of Representative German Data (KiGGS).

Introduction: Preterm birth is a global scourge, the leading cause of perinatal mortality and morbidity. This study set out to identify the principal risk factors for preterm birth, based on the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). A range of possible factors influencing preterm birth were selected for inclusion in the questionnaire, covering factors such as gender, national origin, immigrant background, demography, living standard, family structure, parental education and vocational training. Methods: All data were taken from the aforementioned KiGGS survey conducted between 2003 and 2006. A total of 17 641 children and adolescents (8656 girls and 8985 boys) drawn from 167 German towns and municipalities deemed to be representative of the Federal Republic of Germany were included in the study. Gestational age at birth was available for 14 234 datasets. The questionnaire included questions from the following areas as possible factors influencing preterm birth: gender, national origins, immigrant background, demography, living standard, family structure, parental education and vocational training. Results: The preterm birth rate was 11.6 %, higher than that of other national statistical evaluations. Around 57.4 % of multiple pregnancies and 10 % of singleton pregnancies resulted in preterm delivery. Multiple pregnancy was found to be the most important risk factor (OR 13.116). With regard to national origins and immigration background, mothers from Turkey, the Middle East, and North Africa had a higher incidence of preterm birth. Preterm birth was more prevalent in cities and large towns than in small towns and villages. Conclusion: Risk factors associated with preterm birth were identified. These should help with the early identification of pregnant women at risk. The preterm birth rate in our survey was higher than that found in other national statistical evaluations based on process data. More than half of all multiple pregnancies ended in preterm birth.

Right-sided pulmonary aplasia: longitudinal lung function studies in two cases and comparison to results from term healthy neonates.

Agenesis of the right lung was diagnosed prenatally in two neonates born at 36 and 37 weeks, respectively. Computed tomographic scans and magnetic resonance imaging indicated that both cases had a Type 2 pulmonary agenesis, which was confirmed later by bronchoscopy. Both patients were clinically stable during the neonatal period. Serial pulmonary function tests revealed a decrease in specific respiratory system compliance (sCrs) in both neonates and a marked discrepancy between functional residual capacity measured by the nitrogen washout technique (FRCN2) and by plethysmography (FRCpleth) on follow-up. Early decrease of respiratory system compliance (Crs) and increase of respiratory system resistance (Rrs) in one infant preceded the onset of tracheal stenosis, which remained asymptomatic until the age of 8 weeks, when the infant developed acute respiratory failure requiring intubation and mechanical ventilation with high airway pressures. Aortopexy, implantation of a tissue expander into the right hemithorax, and laser ablation of fibrotic tissue at the site of tracheal stenosis were performed to achieve successful extubation. The second infant remained asymptomatic. Values for lung mechanics and volumes for both infants with pulmonary aplasia were as follows: Crs, 3.43 and 10.60 mL x kP(-1) x kg(-1); sCrs, 0.23 and 1.28 kpa(-1); Rrs, 11.1 and 7.4 kpa x s x L(-1); FRCN2, 14.9 and 10.2 mL x kg(-1); FRCpleth, 28.2 and 25.8 mL x kg(-1); FRCN2: FRCpleth ratio, 0.56 and 0.54 for patients 1 and 2, respectively. These values differed considerably from results of a control group of nine term healthy neonates (Crs, 10.0+/-1.8 mL x kPa(-1) x kg(-1); sCrs, 0.43+/-0.08 kpa(-1); Rrs, 5.10+/-0.55 kpa x s x L(-1); FRCN2, 24.0+/-2.5 mL x kg(-1); FRCpleth, 31.1+/-6.0 mL x kg(-1); FRCN2:FRCpleth ratio, 0.78+/-0.10). In conclusion, serial assessment of lung mechanics and pulmonary gas volumes detects airway obstruction early in neonates with unilateral lung agenesis. Bronchoscopy is recommended. Along with conventional surgical procedures, an expandable implant may improve management or prevent respiratory failure in selected cases.

Conversion of umbilical arterial Doppler waveforms to cardiac cycle triggering signals: a preparatory study for online motion-gated three-dimensional fetal echocardiography.

To remove motion artefacts, a device was built to convert "noisy" umbilical arterial Doppler waveforms (UADWs) from an ultrasound (US) system into sharp ECG R-wave-like cardiac cycle triggering signals (CCTSs). These CCTSs were then used to gate a simultaneous (online) 3-D acquisition of sectional fetal echocardiograms from another US system. To test the conversion performance, a study was carried out in sheep fetal twins. Pulmonary arterial flow waveforms (PAFWs) from implanted probes were traced, in the meantime, to determine the reference cardiac cycle. Interference caused by running the two nonsynchronised US systems was controlled to three degrees (not-noticeable, moderate, and severe), together with high (> or = 40 cm/s) and low (< 40) flow velocities on UADWs. The conversion efficiency, assessed by the percentage of UADWs converted into CCTSs, was in the range of 83% to 100% for not-noticeable and moderate interference, and 0% to 71% for severe interference. The triggering accuracy, assessed by [(time lag mean between the onsets of PAFWs and corresponding CCTSs) -- (its 99% confidence level)] / the mean, was 90% to 96% for the not-noticeable interference high- and low-flow groups and for the moderate interference high-flow group; 19% to 93% for the moderate interference low-flow group; and from not obtainable up to 90% for the severe interference groups. The results show that UADWs can be used as a satisfactory online motion-gating source even in the presence of moderate interference. The major problems are from severe interference or moderate interference with low-flow velocity, which can be minimised/eliminated by the integration of the individual systems involved.

Impact of intrapartal ultrasound to assess fetal head position and station on the type of obstetrical interventions at full cervical dilatation.

OBJECTIVES: Recent ultrasound studies have shown that it is feasible to objectively and reproducibly assess fetal head position and station within the pelvis. We sought to evaluate the impact of this new approach on decision making by physicians in a cohort of women with a prolonged second stage of labor. METHODS: This was a retrospective cohort study that included all women with fetuses in cephalic presentation, who were diagnosed with a prolonged second stage of labor, and who delivered in a 1-year period. We compared a group of women (n = 121) with a prolonged second stage of labor who underwent intrapartal ultrasound prior to obstetrical intervention (Group A, n = 43) with a group of women for whom the delivery modus was decided upon after clinical digital examination alone (Group B, n = 78). RESULTS: There were no significant differences in maternal and neonatal morbidity between both groups. The rate of second-stage cesarean section was significantly higher (p < 0.50) in Group B without ultrasound compared to Group A with ultrasound prior to operative delivery (20/78 vs. 7/43). Seven patients in Group A delivered spontaneously, but none of the patients in Group B had spontaneous deliveries. CONCLUSIONS: Intrapartal ultrasound in patients with a prolonged second stage of labor may change obstetrical practice by reducing the number of second stage cesarean section without increasing maternal and neonatal morbidity.

Outcome of 60 neonates who had ARED flow prenatally compared with a matched control group of appropriate-for-gestational age preterm neonates.

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.

[Three-dimensional power Doppler ultrasonography (3D-PDU) in fetal diagnosis]. / Der 3D-Power-Doppler-Ultraschall (3D-PDU) in der fetalen Diagnostik.

AIM: 3D power Doppler ultrasonography (3D-PDU) is a new method which allows the spatial presentation of fetal vessels in utero. In the presented study we have examined the feasibility of this technique in prenatal diagnosis. Aim of our pilot study with normal human fetuses was to determine the adjustment of the system presets, the optimal insonation planes and the regions of interest. MATERIAL AND METHODS: Seven regions of interest were examined in three different planes. The 3D volume was acquired by a free hand sweep. The feasibility of the method was quantitatively determined for every plane and region. For each of the three planes a total of 25 examinations was planned and the successful rate per region of interest was then assessed for the total of these 75 examinations. In a two year period, a total number of 80 fetuses from 16 to 34 weeks' gestation could be enrolled in the study. RESULTS: Best examinations were achieved in the vessels of the umbilical cord (successful rate 100 %), followed by the placental and abdominal (84 % each), cerebral (80 %), pulmonary (64 %), and renal vessels (51 %). The most difficult conditions for examination and the most unreliable results were found for the fetal heart with a success rate of only 31 % of the cases. Similar to the experience in 2D power Doppler, a plane with blood flow towards the transducer was the best insonation plane. CONCLUSIONS: In our study we were able to show that a three dimensional demonstration of fetal vessels is possible with the system used. The feasibility is limited by fetal movements and unfavourable fetal positioning. The possible benefit of the method is to diagnose complex fetal vascular malformations in the future.

Application of three-dimensional power Doppler ultrasound in prenatal diagnosis.

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.

Caliber of the coronary sinus in fetuses with cardiac defects with and without left persistent superior vena cava and in growth-restricted fetuses with heart-sparing effect.

OBJECTIVE: To assess reference ranges for fetal coronary sinus (CS) diameter and to compare them with values from fetuses showing heart defects with and without left superior vena cava (LSVC) as well as with severe intrauterine growth retardation and heart-sparing effect on color Doppler. METHODS: The coronary sinus was visualized on two-dimensional ultrasound in a plane slightly caudal to the apical four-chamber view. For the normal range of the size of the CS in relation to gestational age, data was collected from 108/114 (95%) normal fetuses with good visualization between 20 weeks' gestation and term. Abnormal conditions comprised two groups: group 1 consisted of 52 fetuses with heart anomalies, including three subgroups: 11 fetuses with isolated LSVC emptying into the coronary sinus, 12 fetuses with LSVC associated with structural heart defects and 29 fetuses with structural heart defects but without LSVC. Group 2 consisted of 11 fetuses with severe intrauterine growth retardation and dilated coronary arteries as seen by color Doppler ultrasound. RESULTS: Under normal conditions, there was a significant increase in the CS diameter with advancing gestational age (1.2-2.7 mm). Significant dilatation was found only in the two groups with LSVC (range 2.7-6.5 mm), independent of whether the finding was isolated or associated with cardiac defects. CONCLUSION: CS visualization and measurements are easily feasible in the human fetus in the apical four-chamber view. Significant dilatation of the CS is a sign of LSVC. The examiner should be aware of this condition as such dilatation is commonly falsely diagnosed as atrial or atrioventricular septal defect.

Doppler assessment of tracheal and nasal fluid flow during fetal breathing movements: preliminary observations.

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.

Prenatal diagnosis of laryngeal atresia in two cases of congenital high airway obstruction syndrome (CHAOS).

Complete occlusion of the upper airways is known to cause secondary morphological changes, including bilaterally enlarged hyperechogenic lungs, dilated trachea, and hydrops. Prenatal diagnosis of upper airway obstruction has been described in several cases. In these reports, the diagnosis was primarily attributed to indirect signs, and the authors were in doubt as to whether the location of the obstructed area (larynx, glottis or trachea) could be precisely visualized by ultrasound. In this paper two cases are reported presenting the features of congenital high airway obstruction syndrome (CHAOS) diagnosed at the 22nd week of gestation. In both cases, the upper neck was perfectly visualized in a coronal plane. At the onset of fetal breathing movements, the stenotic larynx remained in a closed position. By positioning a colour signal on the fluid-filled dilated trachea, we noticed absence of flow throughout the onset of breathing activity. We conclude that the atretic area must be situated at the level of the larynx. Because of the poor prognosis of laryngeal stenosis and the presence of associated anomalies, both pregnancies were terminated in the 23rd week. This report shows that the application of colour and spectral Doppler may be helpful in the differential diagnosis of fetuses with CHAOS.

Prenatal diagnosis of right lung agenesis using color Doppler and magnetic resonance imaging.

Unilateral lung agenesis should be suspected in fetuses presenting mediastinal shifting and absence of evidence of diaphragmatic hernia. Confirmation of diagnosis is not possible until birth as other more common lung anomalies may have a similar appearance. We present a case with right lung agenesis diagnosed at 34 weeks of gestation. Important for precise diagnosis was the color Doppler procedure, which revealed the absence of right pulmonary vessels. This is the first case in which unilateral lung agenesis has been recognized prenatally by nonvisualization of the corresponding lung vessels. The prenatally performed magnetic resonance sonography did not offer any advantages over sonography. Postnatally, the diagnosis was confirmed, and sinus venosus defect was also found. To prevent recurrent cardiopulmonary crisis, which could be caused by mediastinal shift, a tissue expander was implanted successfully at 3 months of age.

Ultrasound measurements of the diameter of the fetal trachea, larynx and pharynx throughout gestation applicability to prenatal diagnosis of obstructive anomalies of the upper respiratory-digestive tract.

The purpose of the present study was to obtain normative data for the fetal upper respiratory tract by using high-resolution ultrasound techniques. Furthermore, we wanted to test the potential utility of the resulting normograms in diagnosing obstructive lesions of the trachea and oesophagus. Sonographic measurements of the diameters of the trachea, larynx and pharynx were obtained at well-defined planes from a prospective cross-sectional sample of 198 normal patients of known gestational age between 15 and 40 weeks' gestation. All measurements were performed during fetal apnea and in the absence of swallowing. The same measurements were also obtained from two cases with laryngeal atresia and three cases with oesophageal atresia, all of which were diagnosed prenatally. The data obtained were plotted on the constructed normograms. In normal fetuses approximately linear relationships existed between tracheal, laryngeal and pharyngeal diameter, on the one hand, and gestational age, on the other, with the measurements correlating significantly (p<0.0001) with gestational age. The linear regression coefficients (r2) for the tracheal, laryngeal and pharyngeal diameters were 0.66, 0.55 and 0.32, respectively. The 95 per cent prediction limits were also calculated. In fetuses with laryngeal atresia only the tracheal diameter was significantly higher as compared with that of normal fetuses. Data of the fetuses with oesophageal atresia showed that there were no changes in the upper airway anatomy. Our study provides normative data for the upper respiratory tract. In the prenatal diagnosis of obstructive neck anomalies the usefulness of the data would seem to be limited to those affecting the respiratory tract. Among the structures measured, only the trachea may prove to be of clinical significance.

The upper neck pouch sign: a prenatal sonographic marker for esophageal atresia.

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.

Prenatal sonographic features of a rhabdoid tumor of the kidney.

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.

Reliability of prenatal sonographic lung biometry in the diagnosis of pulmonary hypoplasia.

OBJECTIVE: The purpose of the present study was to assess the value of biometric lung measurements for the diagnosis of severe fetal pulmonary hypoplasia by investigating whether a significant correlation between two-dimensional lung biometry measurements and autopsy findings could be established. METHODS: This was a prospective study carried out between 1995 and 1997. Nomograms for normal fetuses of the anterior-posterior and transverse inner thoracic diameters, which describe the growth and shape of the lung, were used as a basis for diagnosis of pulmonary hypoplasia in fetuses at high risk of developing the condition (the fetuses had bilateral renal agenesis or multicystic kidneys; chronic PROM <25 gestational weeks or hydrothorax). Pregnancy was terminated by abortion or intrauterine death in 29/43 high-risk fetuses and autopsies were performed. Only the 29 fetuses for which there were autopsy findings were included in the study. RESULTS: The best plane for diagnosing pulmonary hypoplasia was the four-chamber view. The diagnostic accuracy for this view as expressed by the sensitivity was 57% for the anterior-posterior diameter and 44% for the transverse diameter; as expressed by the specificity it was 42% for the anterior-posterior diameter and 50% for the transverse diameter. The results for the four-chamber view for the various high-risk conditions were as follows: for fetuses with chronic PROM we obtained sensitivities of 75% and 50% (anterior-posterior and transverse dimensions, respectively) and specificities of 80% and 60% (anterior-posterior and transverse dimensions, respectively). The sensitivities of lung biometry in fetuses with hydrothorax were 1% and 80% for the two diameters, but there was a low specificity. In fetuses with bilateral renal agenesis or multicystic kidneys we obtained sensitivities of 36% and 30% (anterior-posterior and transverse dimensions, respectively) and a specificity of 50% (anterior-posterior dimension). CONCLUSIONS: The present results show that two-dimensional lung biometry is not a suitable method for antenatal detection of pulmonary hypoplasia. However, in individual cases with high risk for pulmonary hypoplasia, lung biometry might prove to be an additional diagnostic parameter.