Ultrasound evaluation of the fetal skull base throughout pregnancy.

OBJECTIVE: To construct nomograms for cranial base parameters of normal fetuses. STUDY DESIGN: A cross-sectional study of 386 normal singleton fetuses at 14-40 weeks' gestation. Measurements of the length and width of the sphenoid bone anteriorly and the otic cartilage posteriorly and of the angles between the ridges were obtained. RESULTS: Nomograms of the length and width of sphenoid ridge and otic cartilage, and of the angles in the cranial fossae are presented. A linear growth function was observed between cranial base measurements (sphenoid ridge length, otic cartilage length, cranial base angles) and gestational age, femur length and biparietal diameter. CONCLUSION: Measurements of the length of cranial base ridges and the angles between them can be obtained easily in the second and third trimesters and might prove useful in the evaluation of pregnancies at high risk for associated fetal abnormalities.     

Nomograms of sonographic measurements throughout gestation of the fetal hard palate width, length and area.

OBJECTIVE: To assess the feasibility of sonographic depiction of the fetal hard palate and secondarily to create nomograms throughout gestation of its sonographic width, length and area. METHODS: This was a cross-sectional study of pregnant patients between 15 and 41 weeks' gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), and singleton, non-anomalous fetuses. Sonographic measurements obtained included biparietal diameter, head circumference, abdominal circumference and femur length. Fetal hard palate measurements included maximum width, maximum length and the calculated area. Tables were prepared depicting the estimated mean +/- SD and 5(th), 50(th) and 95(th) centiles at each gestational week between 15 and 41 weeks. Pearson's correlation coefficient and associated P-values for the relationships between fetal hard palate measurements and other sonographic measurements and coefficients of variation for each of the fetal hard palate measurements were calculated. RESULTS: The study included 602 consecutive patients. The mean maternal age was 28.7 +/- 6.3 years, with median gravidity of 2 (range, 1-12) and parity 1 (range, 0-8). All attempts at obtaining fetal hard palate ultrasound measurements were successful. Mean fetal hard palate width (cm) = -0.73579345 + 0.11370432 x GA - 0.00083919 x GA(2) and SD = -0.017842055 + 0.005142475 x GA, where GA is gestational age in weeks. Mean fetal hard palate length (cm) = -0.82020463 + 0.11767777 x GA - 0.00092801 x GA(2) and SD = -0.043064317 + 0.006378869 x GA. Mean fetal hard palate area (cm(2)) = -2.40090641 + 0.17136556 x GA + 0.00097308 x GA(2) and SD = -0.603647741 + 0.040740282 x GA. Sonographic measurements of the fetal hard palate width, length and area correlated significantly and strongly with gestational age (all P < 0.001) and significantly but less strongly with femur length (P = 0.004). CONCLUSION: The fetal hard palate may be depicted sonographically with relative ease between 15 and 41 weeks' gestation and measurements of the fetal hard palate width, length and area correlate well with gestational age, biparietal diameter, abdominal circumference, sonographic estimated fetal weight, and femur length.     

Ultrasound antenatal diagnosis of cleft palate by a new technique: the 3D "reverse face" view.

OBJECTIVE: To assess the clinical value of a novel three-dimensional (3D) ultrasound technique, the reverse face view (3D RF view), in the antenatal categorization of facial clefting and in particular clefting of the hard palate. METHODS: Eight cases of suspected orofacial clefting were examined by 3D surface rendering. The fetal lips and alveolar ridge were examined in the frontal plane and the face was then rotated through 180 degrees on the vertical axis to examine the secondary palate by the 3D RF view. RESULTS: In each case described, we were able to visualize the fetal face, lips and palate and make an antenatal diagnosis as to whether the palate was affected. In all cases, the antenatal diagnosis was subsequently confirmed. In one case with a left-sided cleft in the lips and alveolar ridge and an intact hard palate, the correct diagnosis was made but a cleft in the soft palate was missed. CONCLUSION: Although clefts of the lips and alveolar ridge are readily diagnosed on high-quality antenatal ultrasound, visualization of the fetal palate using existing techniques is unreliable. In the patients described here, the 3D RF technique allowed relatively straightforward assessment of the fetal palate with a high degree of accuracy.     

Prenatal diagnosis of cleft palate: contribution of color Doppler ultrasound.

The antenatal diagnosis of cleft palate by ultrasound can sometimes be difficult by conventional B-mode imaging, especially when the tongue is in its normal position.We describe two cases which illustrate the value of color Doppler in the antenatal diagnosis of cleft palate. In the first case, at 32 weeks' gestation, there was a large defect with a massive passage of flow extending from the buccal cavity into one of the nasal fossae. In the second case, at 22 weeks' gestation, a parasagittal view demonstrated the fetal tongue to be in the normal position, but there was an abnormal trajectory off low from the buccal cavity into one of the nasal fossae followed by an exit at the level of the cleft. Although a cleft lip was demonstrated on B-mode imaging, we would not have been able to make the diagnosis of cleft palate without color Doppler.This is the first report describing the contribution of color Doppler to the antenatal diagnosis of cleft palate.     

Prenatal ultrasonography and the diagnosis of fetal cleft lip.

OBJECTIVE: To determine the efficacy of obstetric ultrasonography in the detection of fetal cleft lip. METHODS: The study population included all women who had a fetal anatomic survey with adequate visualization of the face and who gave birth at Brigham and Women's Hospital between January 1, 1990, and January 31, 2000. All neonates born with cleft lip were identified from the Brigham and Women's Active Malformation Surveillance Program. Confirmation of the anatomic defect was obtained from the pediatric record or from the pathologic report if the pregnancy was terminated or ended in miscarriage. Cases of isolated cleft palate were excluded. An ultrasonography database was used to identify all cases of cleft lip diagnosed before delivery. Maternal information regarding the pregnancy was abstracted from the medical record. Statistical significance was determined using the chi2 statistic for categorical variables and the t test for continuous variables. RESULTS: A total of 56 confirmed cases of cleft lip were identified in the study population. Overall, 73% of the cases (41 of 56) were identified antenatally. Additional fetal anomalies were present in 54% of the cases (30 of 56). A comparison between those cases that were detected and those in which the diagnosis was missed showed that there was a significantly lower detection rate if the ultrasonography was performed before 20 weeks (12 [57%] of 21 versus 29 [83%] of 35; P = .035). There was no difference between the 2 groups in terms of maternal age or weight. Maternal parity, prior maternal abdominal surgery, the presence of a multiple gestation, or coexisting fetal anomalies did not significantly affect the detection rate. There was no difference in detection rate in the first half of the study period (1990-1995; 23 [72%] of 32) compared with the second half (1996-2000; 18 [76%] of 24; P = .79). CONCLUSIONS: In this cohort of women, the rate of detection of fetal cleft lip was significantly lower when the anatomic survey was performed before 20 weeks' gestation. This difference could not be accounted for by such variables as prior maternal abdominal surgery, coexisting fetal anomalies, or improvements in ultrasonographic detection with time. We recommend that the anatomic survey for fetuses at high risk for this condition be performed after 20 weeks' gestation.     

Axial ultrasonographic imaging of the fetal maxilla for accurate characterization of facial clefts.

The purpose of this study was to determine whether scanning of the fetal midface in the axial plane allows accurate characterization of facial clefts. During fetal anatomic survey, facial clefts were identified in six fetuses. The midface anatomy was evaluated with ultrasonography in the coronal and axial planes, and the clefts were characterized prospectively as unilateral or bilateral and as involving the lip alone or both the lip and the palate. The integrity of the upper lip was assessed in the coronal and axial planes. The continuity of the normal C-shaped curve of the tooth-bearing alveolar ridge and the anterior six tooth sockets was assessed in the axial plane. The prospective prenatal diagnosis was correlated with postnatal findings in all cases. The clefts where characterized prospectively as unilateral cleft lip (one case), unilateral cleft lip and cleft palate (four cases), and bilateral cleft lip and cleft palate (one case). The prenatal characterization was confirmed to be correct postnatally in all cases. Prenatal sonographic evaluation of the axial view of the tooth-bearing alveolar ridge of the maxilla allows accurate determination of whether a cleft is confined to the lip or involves both the lip and the palate.     

Sonographic assessment of normal fetal palate using three-dimensional imaging: a new technique.

OBJECTIVES: The aim of this study was to describe a novel three-dimensional (3D) ultrasound rendering technique to examine the normal fetal posterior palate and to assess its correspondence with the real fetal anatomy. METHODS: A prospective longitudinal study was conducted from January to October 2005 and included 100 fetuses in a low-risk population. Fetal ultrasound examinations were performed at 17, 22, 27 and 32 weeks' gestation to determine the normal 3D ultrasound view of the fetal palate at different gestational ages. The ultrasound scans were performed using the strict anterior axial plane of the starting reconstruction volume and the underside 3D view of the fetal palate. The 3D view of the fetal palate was compared with the normal anatomical view of the fetal palate obtained by surgical fetopathological examination of fetuses at the same gestational ages. The sonographic visualization rates of seven defined anatomical landmarks of the fetal palate were computed for each gestational age. The visualization rates across gestational ages were compared by use of the Cochrane Q test. The reliability of detection of each anatomical landmark across gestational ages was determined by Cronbach's Alpha. RESULTS: In all cases a 3D ultrasound view of the fetal maxilla and secondary palate was obtained at each period of gestation and corresponded well to the fetal anatomical specimens. The seven defined anatomical landmarks of the fetal palate were identified in 42-100% of cases. The visualization rates across gestational ages were significantly different in five of these anatomical landmarks. These differences can be explained by different developmental processes of these anatomical structures. The overall reliability of visualization across the gestational ages for the anatomical landmarks was medium to very high (0.73-0.96), except for the landmark interpalatal suture which was low (0.48). CONCLUSIONS: This technique of anterior axial 3D view reconstruction of the fetal palate seen by an underside view can provide unique diagnostic information on the integrity of the secondary palate. This innovative, simple and rapid technique may become the reference technique in ultrasound investigation of the fetal palate, and should be of value in diagnosing isolated secondary cleft palate or palatal involvement when cleft lip and alveolus are diagnosed.     

Improving cleft palate/cleft lip antenatal diagnosis by 3-dimensional sonography: the "flipped face" view.

OBJECTIVE: Three-dimensional sonography has enhanced the diagnosis of congenital anomalies in the early stages of pregnancy. Both cleft lip and palate remain a diagnostic challenge for the sonographer because of the variable size of the defects as well as their location. Recently, a technique described by Campbell et al (Ultrasound Obstet Gynecol 2003; 22:552-554, 2005; 25:12-18) demonstrated an improved method called the "reverse face" view, which appears to assist in the diagnosis of clefts involving the palate. METHODS: The fetal face was initially examined with the fetus in the supine position. Using 3-dimensional sonography, a static volume was acquired. Following acquisition of the volume, it was rotated 90 degrees so that the cut plane was directed in a plane from the chin to the nose. The volume cut plane was then scrolled from the chin to the nose to examine in sequential order the lower lip, mandible, and alveolar ridge; tongue; upper lip, maxilla, and alveolar ridge; and hard and soft palates. RESULTS: This approach identified the full length and width of the structures of the mouth and palates and allows the examiner to identify normal anatomy as well as clefts of the hard and soft palates. CONCLUSIONS: The fetal hard and soft palates of the mouth can be accessed using a new technique, which we call the "flipped face" maneuver, when an adequate volume of the face can be obtained.     

The premaxillary triangle: clue to the diagnosis of cleft lip and palate.

OBJECTIVE: The prenatal detection rate of cleft lip and palate is low, especially in low-risk patients who undergo targeted sonography. The reason is that evaluating surface anatomy is relatively difficult and requires operator expertise. Our purpose was to describe a technique to improve the diagnostic accuracy of facial clefts (lip and palate) and to assess the feasibility of including this technique as part of standard protocol during targeted imaging. METHODS: A prospective study was done during 2000 through 2002 to evaluate the accuracy of the "premaxillary triangle (PMT) sign": a new sign to diagnose unilateral cleft lip and palate in women referred for prenatal sonography at our center. Patients with only isolated unilateral cleft lip and palate and cleft lip were included in this study. Before this, all examiners were trained to image the PMT. The images were reviewed by a senior consultant. It was later decided to include this sign as part of the protocol of targeted sonography done between 18 and 22 weeks in our institution. However, depending on the fetal position, the PMT was documented even in patients referred for the first time in late second and third trimesters. RESULTS: Twenty-nine cases of isolated facial clefts were diagnosed during the study period, of which 2 had unilateral cleft lip and 27 had unilateral cleft lip and palate. The PMT sign was absent in all cases of unilateral cleft lip and palate but was present in 2 cases of isolated cleft lip without cleft palate. CONCLUSIONS: The PMT sign can be easily incorporated into targeted sonography at 18 to 22 weeks' gestation. Its inclusion would help in increasing the detection rate of unilateral cleft lip and palate. It may also be potentially used for differentiating between isolated cleft lip and cleft lip and palate, which helps in better prenatal counseling.     

A novel technique for visualization of the normal and cleft fetal secondary palate: angled insonation and three-dimensional ultrasound.

OBJECTIVE: To evaluate the effectiveness of a novel approach to the visualization of the fetal secondary palate using three-dimensional (3D) ultrasound. METHODS: Sonographic examinations were performed in normal fetuses and in one fetus with cleft lip and palate. To avoid acoustic shadowing from the alveolar ridge, the secondary palate was insonated at a 45 degrees angle in the sagittal plane, and 3D ultrasound was used to reconstruct axial and coronal planes. RESULTS: The secondary palate was successfully visualized in 10 of 15 normal fetuses, both in the axial and coronal planes. In the fetus with cleft lip and palate the lesion of the secondary palate was clearly demonstrated, particularly in the coronal plane. CONCLUSION: Angled insonation and 3D ultrasound allow clear visualization of normal and cleft secondary palate.     

Fetal compensatory renal hypertrophy with a unilateral functioning kidney.

OBJECTIVE: To evaluate the possibility of fetal compensatory renal hypertrophy with a unilateral functioning kidney. METHODS: A nomogram of renal length was established from 254 normal fetuses. Renal length was also obtained in 14 fetuses with unilateral renal agenesis and 22 fetuses with a unilateral multicystic kidney. RESULTS: Compensatory renal hypertrophy, defined as a renal length > 95th percentile for gestational age, occurred in 16 of 36 cases (44.4%). CONCLUSIONS: Compensatory renal hypertrophy is detectable in utero and may occur as early as 22 weeks' gestation.     

The development of the fetal sternum: a cross-sectional sonographic study.

OBJECTIVE: To assess the relationship between gestational age and sonographic appearance of the various sternal components and establish growth during human gestation. DESIGN: A prospective cross-sectional study. METHODS: The study was performed on 252 consecutive normal singleton pregnancies from 19 weeks of gestation until term, using transabdominal high-resolution ultrasound techniques. The sternal length, as well as the number of ossification centers at each gestational age, were recorded. RESULTS: The first occasion at which a fetal human sternum could be visualized with two to three ossification centers was at 19 weeks' gestational age. The fifth ossification center was first visualized at 29 weeks' gestation. The mean +/- SE of sternal length varied from 15 +/- 0.98 mm (95% confidence interval (CI) 12.79-17.21) at 19-20 weeks, to 36.50 +/- 0.29 mm (95% CI 35.58-37.42) at 37-38 weeks' gestation. Sternal length as a function of gestational age was expressed by the regression equation: sternal length (mm) = -11.06 + 1.39 x gestational age (weeks). The correlation coefficient, r = 0.924 for sternal length, was found to be highly statistically significant (p < 0.0001). CONCLUSIONS: The presented data offer normative measurements of the fetal sternum which may be helpful in the prenatal diagnosis of congenital syndromes that include, among other manifestations, abnormalities of sternal development.     

胎儿硬腭的三维超声显像方法及其应用

目的探讨胎儿硬腭的三维超声显像方法及其在产前诊断胎儿腭裂中的应用价值。方法采集100胎孕13～35周正常胎儿及32胎唇裂胎儿颜面部的三维容积数据,通过旋转x、y、z轴、调节灰度阈值和片层,显示观察胎儿硬腭矢状面、冠状面和横断面声像图。结果正常胎儿硬腭矢状面显示率为93.00%(93/100),呈前后走向的带状稍强回声,表面光滑,前方与上牙槽突强回声相延续;冠状面显示率为91.00%(91/100),冠状面上硬腭位于中部,呈连续的弧形带状稍强回声,与上方鼻骨强回声构成三角关系;横断面显示率为90.00%(90/100),横断面上硬腭呈拱门形稍强回声,前方、左、右侧被上牙槽突强回声所包围;88.00%(88/100)的胎儿硬腭在3个位面上均可显示。32胎唇裂胎儿中,检出9胎合并腭裂并经随访证实,其腭裂部位、裂隙宽度、整体形态及走向显示清楚。结论应用三维超声观察胎儿硬腭简便易行。掌握正常胎儿硬腭三维超声声像图特征有助于提高胎儿腭裂的检出率及评判预后。     

Fetal clavicle length throughout gestation: a nomogram.

OBJECTIVE: To create a nomogram of fetal clavicle length (CL) throughout gestation. METHODS: Cross-sectional study of patients between 14 and 42 weeks' gestation. Inclusion criteria consisted of well-established dates (consistent with early ultrasound), singleton, non-anomalous fetuses, and intact amniotic membranes. Sonographic measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL) and sonographically estimated fetal weight (SEFW). For every case, the average of three separate measurements of the CL was used. The 5th, 50th and 95th centiles were obtained by least squares regression. Pearson's correlation coefficient and associated P-values for the relationships between CL and other biometric measurements were calculated. The data were compared to a nomogram of the CL generated in 1985 from the measurement of 85 fetuses. RESULTS: A total of 623 consecutive patients were studied. In all but three cases, CL was successfully measured. Mean maternal age was 27.7 +/- 6.2 years, median gravidity 3 (range, 1-14) and median parity 1 (range, 0-9). Mean CL (mm) = -75.30 + 32.70*ln(GA) and SD = -0.41 + 0.08328*GA, where ln represents the natural logarithm and GA the gestational age in weeks. Fetal CL correlated significantly and strongly with BPD, HC, AC, HL, FL and the logarithm of SEFW, with Pearson correlation values of 0.973, 0.977, 0.976, 0.979, 0.977 and 0.979, respectively (all P < 0.001). Measurements according to comparable 1985 data were consistently substantially below the present data (smaller CL for any given GA except below 17 weeks' gestation). CONCLUSIONS: We propose a new nomogram of CL, which differs significantly from the previously published nomogram. We suggest that the present data reflect the use of high-resolution ultrasound technology and propose that these data, based on a large number of fetuses, replace the previous nomogram. We also suggest that the '1 mm = 1 week' rule of thumb should no longer be used, since it can be erroneous by as much as 6 weeks.     

Nomogram of Wharton's jelly as depicted in the sonographic cross section of the umbilical cord.

OBJECTIVES: To generate a nomogram for the sonographic measurement of Wharton's jelly area (WJA) during gestation and to investigate whether WJA is related to fetal biometric parameters. METHOD: The sonographic cross-sectional area of the umbilical cord and of its vessels was measured in 659 fetuses between 15 and 42 weeks of gestation. The WJA was calculated by subtracting the vascular area from the umbilical cord area. The conventional biometric parameters were measured and correlated with the WJA. Polynomial regression analysis was utilized for statistical purposes. RESULTS: The WJA increased as a function of gestational age (r = 0.63, P < 0.001). The regression equation for the mean WJA (y) according to gestational age (x) was y = -114.7 + 4.142x - 0.01x2 and for the standard deviation (y') was y' = -7.567 + 1.319x. There was a strong correlation between the WJA and the umbilical cord area (r = 0.97, P < 0.001). A significant correlation was also found between the WJA and fetal biometric parameters before 32 weeks of gestation (WJA and biparietal diameter: r = 0.82, P < 0.001; WJA and abdominal circumference: r = 0.79, P < 0.001; WJA and femur length: r = 0.81, P < 0.001) while after 32 weeks of gestation no correlations were found between WJA and fetal anthropometric parameters. CONCLUSION: A nomogram for the WJA has been generated. The WJA increases as a function of gestational age and it is correlated with fetal size up to 32 weeks of gestation.     

二维超声及三维超声多种成像技术在胎儿唇腭裂畸形诊断中的联合应用

目的研究二维超声及三维超声多种成像技术在胎儿唇腭裂畸形诊断中的图像特征。 方法选取2016年1月至2017年12月在南京医科大学附属苏州医院产科接受中孕期结构畸形筛查发现唇腭部异常的胎儿均行三维超声表面成像、断层成像（TUI）及自由解剖成像（OmniView模式）多种成像技术联合检查,并随访至出生后或引产后。结合产前超声检查图像,研究唇腭裂胎儿颜面部三维超声图像特征。 结果产前超声筛查的19 168例中孕期胎儿中检出唇腭部结构畸形36例（0.19%）。36例唇腭裂胎儿超声征象：单纯唇裂（CL）8例,二维、TUI及OmniView模式均检出胎儿唇裂;三维表面成像漏诊1例唇红裂。二维及三维成像技术均显示胎儿上唇连续性中断,但三维成像显示更直观。唇裂合并上牙槽突裂（CLA）11例,二维超声显示8例,三维表面成像、TUI均诊断9例,漏诊2例,OmniView技术诊断10例,漏诊1例,联合检查诊断10例,漏诊1例。主要超声征像：上唇及上牙槽突连续性中断,二维超声对于牙槽突裂显示较困难,TUI及OmniView可从多角度显示牙槽突裂。唇裂合并腭裂（CLP）17例,二维超声（诊断10例）、三维超声表面成像模式（诊断13例）、TUI（诊断15例）、OmniView模式（诊断16例）均未全部检出;而17例CLP经联合检查全部检出。超声征象为上唇、原发腭及继发腭的连续中断,断层成像及OmniView可从多角度显示原发腭及继发腭,优于二维超声对于原发腭及继发腭的显示。 结论产前二维超声及三维超声能清晰显示胎儿唇裂,但对于腭裂,三维超声多种成像模式图像优于二维超声,产前超声筛查联合三维多成像技术能清晰显示胎儿颜面部异常,减少唇腭裂的漏诊。     

Development of the human fetal corpus callosum: a high-resolution, cross-sectional sonographic study.

OBJECTIVE: To establish reference ranges during human pregnancy for normal fetal corpus callosum dimensions. DESIGN: In a prospective, cross-sectional study of 258 fetuses between 16 and 37 weeks of gestation, measurements of the length, width, and thickness at the level of the anterior mid-body of the corpus callosum were performed, using high-resolution, transvaginal and transabdominal transducers. RESULTS: The mean length of the corpus callosum was 27.2 (standard deviation, 1.2; 95% confidence interval, 26.02-28.37) mm. Width and thickness of the corpus callosum were 5.6 (standard deviation, 1.6; 95% confidence interval, 5.41-5.82) mm and 1.9 (standard deviation, 0.7; 95% confidence interval, 1.87-2.06) mm, respectively. The size of the corpus callosum as a function of gestational age was expressed by regression equations: length (mm) = -20.40 + 1.92 x gestational age; width (mm) = -0.052 + 0.225 x gestational age; thickness (mm) = -0.174 + 0.085 x gestational age. The dimension-gestational age correlation coefficients were: r = 0.779 for length, r = 0.676 for width and r = 0.494 for thickness; these were statistically significant (P < 0.01). The maximum increase in thickness and width of the corpus callosum occurred between 19 and 21 weeks' gestation, while its length followed a constant growth rate. The normal mean length, width and thickness of the corpus callosum per week, and the 95% confidence limits, were defined. CONCLUSIONS: The present study offers normative measurements of the fetal corpus callosum and may facilitate a more objective diagnosis of its congenital abnormalities.     

Prediction of preterm birth by second trimester cervical sonography in twin pregnancies.

OBJECTIVES: To determine the predictive value of sonographic cervical length and of funneling for spontaneous preterm delivery (PTD) in twin pregnancies under 26 weeks' gestation. METHODS: Women with twin pregnancies were studied prospectively with transvaginal or translabial ultrasound of the cervix from 18 to 26 weeks' gestation. Exclusion criteria were: signs of preterm labor, prophylactic cervical cerclage, placenta previa, or severe congenital fetal anomaly. The primary outcome was spontaneous preterm birth at < 35 weeks' gestation. RESULTS: Sixty-five twin pregnancies were analyzed, of which 23% (15/65) delivered preterm. Cervical ultrasound examination was performed by 22 weeks' gestation in 75% and by 24 weeks' gestation in 91% of women. Cervical length < or = 25 mm and < or = 30 mm was associated with sensitivities of 27% and 53%, respectively, and with 67% and 62% rates of PTD, respectively (R.R. 4.6, C.I. 2.0-10.3 and R.R. 3.6, C.I. 1.6-7.8, respectively). A cervical length > 35 mm was associated with only a 4% rate of PTD (R.R 0.13; C.I. 0.02-0.93). Of 10 women (15%) with any cervical funneling, 70% delivered preterm, all under 32 weeks' gestation. By logistic regression analysis, both short cervix < or = 30 mm and any funneling were strongly predictive of PTD. CONCLUSIONS: Both cervical length < or = 30 mm and cervical funneling in twin pregnancies under 26 weeks' gestation are independently and strongly associated with high risk for preterm birth. A long cervix, of length > 35 mm, is associated with very low risk (4%) for preterm birth.     

Fetal cleft lip and palate detection by three-dimensional ultrasonography.

OBJECTIVES: To demonstrate a standardized approach for the evaluation of cleft lip and palate by three-dimensional (3D) ultrasonography. DESIGN: This was a retrospective study of seven fetuses with confirmed facial cleft anomalies. Post-natal findings were compared to a blinded review of 3D volume data from abnormal fetuses with seven other normal fetuses that were matched for gestational age. Upper lip integrity was examined by 3D multiplanar imaging. Sequential axial views were used to evaluate the maxillary tooth-bearing alveolar ridge contour and anterior tooth socket alignment. Alveolar ridge disruption suggested cleft palate. Premaxillary protrusion, either by multiplanar imaging or surface rendering, indicated bilateral cleft lip and palate. RESULTS: Post-natal findings confirmed bilateral cleft lip and palate (four cases), unilateral cleft lip and palate (one case), and unilateral cleft lip (two cases). Multiplanar review identified all three fetuses with unilateral cleft lip, three of four fetuses with bilateral cleft lip, one fetus with unilateral cleft palate, and three of four fetuses with bilateral cleft palate. Surface rendering correctly identified all cleft lips, with the exception of one fetus, who was thought to have a unilateral cleft lip and palate, despite the actual presence of a bilateral lesion. One cleft palate defect was directly visualized by 3D surface rendering. No false-positives occurred. CONCLUSION: Interactive review of standardized 3D multiplanar images allows one to evaluate labial defects, abnormalities of the maxillary tooth-bearing alveolar ridge, and presence of premaxillary protrusion for detecting cleft lip and palate anomalies. Surface rendering may increase diagnostic confidence for normal or abnormal studies. This technology provides an array of visualization tools that may improve the prenatal characterization of facial clefts, particularly of the palate.     

Contribution of three-dimensional volume contrast imaging to the sonographic assessment of the fetal uterus.

OBJECTIVE: To investigate the contribution of volume contrast imaging (VCI) in assessing the fetal uterus in normally developed female fetuses. METHODS: The pelvis of 38 normal female fetuses was examined at 20-22 and 32-34 weeks' gestation using both conventional two-dimensional (2D) ultrasound and VCI on the same transverse or oblique longitudinal view of the fetal pelvis. Two experienced sonographers evaluated the ability of both techniques to image the fetal uterus. Results were compared by kappa index to evaluate the interobserver variability. RESULTS: A clear picture of the fetal uterus was obtained in 50% and 82-87% of the cases at 20-22 weeks' gestation and in 80-85% and 95-100% of the cases at 32-34 weeks' gestation using conventional 2D ultrasound and VCI, respectively. There was moderate to good agreement of uterus visualization between the two observers, with kappa values ranging from 0.43 to 0.65. The lower level of agreement was obtained for conventional 2D ultrasound during the second trimester. CONCLUSIONS: Our results suggest that VCI may be successfully applied to prenatal ultrasonography of the fetal pelvis anatomy. By enhancing the contrast between the intrapelvic organs, VCI provides a clearer picture of the fetal uterus.