Comparison of the ratio of second trimester fetal biometric measurements to fetal nasal bone length in fetuses with normal karyotype and trisomy 21.

AIM: In this study, we compared the ratio of second trimester fetal biometric measurements to nasal bone length (NBL) in fetuses with normal karyotype and trisomy 21 to determine their diagnostic prognostic value. MATERIALS AND METHODS: The study included 148 pregnant women who obtained second-trimester ultrasonographic fetal anatomy and had amniocentesis (AS) for fetal karyotyping. The fetal karyotype results divided the groups into normal and trisomy 21 fetuses. Age, obstetric history, first and/or second trimester screening test risk ratios, fetal biometric measurements, and NBL mm, median (MoM) multiples, and percentile values were recorded and compared between groups. RESULTS: BPD/NBL ratios above 9.26 predict trisomy 21 in fetuses with 77.6% sensitivity and 86.1% specificity (p = 0.001). HC/NBL ratios above 34.50 predict trisomy 21 in fetuses with 77.8% sensitivity and 88.8% specificity (p = 0.001). FL/NBL ratios above 6.02 predict trisomy 21 in fetuses with 69.6% sensitivity and 72.2% specificity (p = 0.001). HL/NB ratios above 6.56 predict trisomy 21 in fetuses with 95.5% sensitivity and 47.2% specificity (p = 0.001). The NBL MoM value demonstrated a high diagnostic accuracy for normal-karyotype fetuses (p = 0.021). CONCLUSION: We found that BPD/NBL, HC/NBL, FL/NBL, and HL/NBL ratios differed between fetuses with a normal karyotype and those with trisomy 21, specifically the HC/NBL ratio, which predicted trisomy 21 with good diagnostic accuracy. In identifying normal-karyotype fetuses, the NBL MoM was highly accurate.

Embryology of the naso-palatal complex in Gekkota based on detailed 3D analysis in Lepidodactylus lugubris and Eublepharis macularius.

The vomeronasal organ (VNO), nasal cavity, lacrimal duct, choanal groove, and associated parts of the superficial (soft tissue) palate are called the naso-palatal complex. Despite the morphological diversity of the squamate noses, little is known about the embryological basis of this variation. Moreover, developmental data might be especially interesting in light of the morpho-molecular discordance of squamate phylogeny, since a 'molecular scenario' implies an occurrence of unexpected scale of homoplasy also in olfactory systems. In this study, we used X-ray microtomography and light microscopy to describe morphogenesis of the naso-palatal complex in two gekkotans: Lepidodactylus lugubris (Gekkonidae) and Eublepharis macularius (Eublepharidae). Our embryological data confirmed recent findings about the nature of some developmental processes in squamates, for example, involvement of the lateral nasal prominence in the formation of the choanal groove. Moreover, our study revealed previously unknown differences between the studied gekkotans and allows us to propose redefinition of the anterior concha of Sphenodon. Interpretation of some described conditions might be problematic in the phylogenetic context, since they represent unknown: squamate, nonophidian squamate, or gekkotan features.

Fetal Nasal Bone Length in the East African Population.

OBJECTIVES: To establish normal ranges of fetal nasal bone length throughout gestation in the East African population and to subsequently compare these measurements with the standardized reference. METHODS: A retrospective cross-sectional study was performed at the University of Minnesota from January 2011 to December 2016. Fetal nasal bone length measurements were generated in a midsagittal plane at an angle of insonation of 45° from ultrasound images of 1407 nonanomalous fetuses of 1130 mothers of East African decent between 14 and 40 weeks' gestation. The proportion of fetal nasal bone lengths of less than 5.2 mm at week 20 of gestation in the East African population was then compared with the 5% noted by the standardized reference by a χ2 test. RESULTS: The fetal nasal bone length increased linearly with advancing gestational age in fetuses of East African mothers (R2 = 0.53; P < .0001). The fetal nasal bone lengths of the East African fetuses were found to be shorter at all ages of gestation compared with the standard reference. At 20 weeks' gestation 17% (95% confidence interval, 13%-22%) of the nasal bone lengths of the East African fetuses were less than 5.2 mm compared with 5% of white and African American fetuses. CONCLUSIONS: Using the standard reference may lead to a greater than 3.5-fold overdiagnosis of hypoplastic nasal bones in the East African population. To improve aneuploidy risk stratification and patient counseling in the East African population, the introduction of a standardized East African-based fetal nasal bone length reference seems warranted.

Reference ranges for foetal nasal bone length, prenasal thickness, and interocular distance at 18 to 24 weeks' gestation in low-risk pregnancies.

BACKGROUND: The aim of the present study was to establish the normal ranges for foetal nasal bone length (NBL), prenasal skin thickness (PNT), interocular distance (IOD), and ratio of prenasal thickness to- nasal bone length (PNT/ NBL) at 18-24 weeks using two-dimensional (2D) ultrasound. METHODS: This study was a retrospective study of prenatal ultrasonographic records from 407 foetuses between 18 and 24 weeks gestational age (GA). The NBL, PNT, IOD, PNT/ NBL ratio, biparietal diameter (BPD), and femur length (FL) were investigated. The relationships among NBL, PNT, IOD, PNT/ NBL, and GA were evaluated. Additionally, descriptive statistics for NBL, PNT, and IOD values for each gestational week were obtained. RESULTS: There was a significant association between GA and NBL, PNT, and IOD between 18 and 24 weeks. NBL increased from a mean of 5.5 mm to 8.3 mm, PNT increased from a mean of 3.5 mm to 5.1 mm, and IOD increased from a mean of 11.1 mm to 14.5 mm. PNT/NBL ratio did not change with gestational age. CONCLUSIONS: This study showed normal ranges for NBL, PNT, IOD, and PNT/ NBL ratios for foetuses between 18 and 24 weeks in low-risk pregnancies. There was a positive linear relationship between GA and NBL, PNT, and IOD. The PNT/NBL ratio might be a more useful measurement than NBL or PNT alone.

Suspicious Prenasal Skin Thickness-to-Nasal Bone Length Ratio: Prevalence and Correlation with Other Markers in Second and Third Trimester Fetuses with Down Syndrome.

PURPOSE: To assess the prevalence and value of a suspicious prenasal skin thickness-to-nasal bone length ratio (PT/NB ratio) in comparison to other established markers in a large population of Down syndrome (DS) fetuses. MATERIALS AND METHODS: This was a retrospective study of 139 DS fetuses and 530 normal fetuses scanned after 14 + 0 weeks of gestation. To characterize diagnostic performance, we used the ROC curve approach. The presence or absence of a PT/NB ratio > 0.8 and 11 other markers were assessed in the group of DS fetuses. A correlation analysis was performed in order to investigate associations between PT/NB ratio and other markers. RESULTS: Among DS fetuses the median PT/NB ratio was 1.06 (IQR 0.729) and was significantly higher compared to normal fetuses with 0.62 (IQR 0.148), (p < 0.001). Gestational age had no influence on the PT/NB ratio. A PT/NB ratio > 0.8 had the highest prevalence of all markers with 89.2 % in the group of DS fetuses, 3 cases were negative for all markers and 3 cases were positive only for PT/NB ratio > 0.8. Marker-specific comparison between prevalences of a suspicious PT/NB ratio with respect to the presence or absence of other markers was statistically significant for hypoplastic NB and major anomalies (p < 0.05). Utilization of at least one of the following five markers was sufficient for detecting 136 out of 139 fetuses with trisomy 21: suspicious PT/NB ratio, hypoplastic NB, nuchal fold thickness, white spot, shortened femur. CONCLUSION: The PT/NB ratio is one of the most powerful indicators of DS in the second trimester. It is objective to interpret, easy to measure, and is reproducible.

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.

Clinical Significance of First-Trimester Screening of the Retronasal Triangle for Identification of Primary Cleft Palate.

OBJECTIVE: To investigate the use of the retronasal triangle (RNT) for identification of orofacial cleft (OC) in the first trimester and the clinical application of three-dimensional (3D) ultrasound techniques for confirming the diagnosis of OC. METHODS: A total of 5,054 women with singleton pregnancies underwent first-trimester screening for Down syndrome at 11-13(+6) weeks. The RNT was scanned in each fetus, and 3D volumetric images of cases with abnormal or indeterminate RNT were obtained. RESULTS: Satisfactory images were obtained from all cases. Seven cases (1.4‰) of abnormal RNT were diagnosed as OC in the first trimester, which were confirmed at a 16 weeks scan or at a postmortem examination. One case that was considered a normal RNT was diagnosed with OC at 22(+2) weeks and after term delivery. Six cases of indeterminate RNT were diagnosed as normal by 3D ultrasound. Identification of OC by visualization of the RNT in the first trimester had a sensitivity of 87.5% and a specificity of 99.9%. CONCLUSION: The RNT is an important sonographic landmark that has a high sensitivity and specificity for the detection of OC in the first trimester. 3D ultrasound is an important tool that aids in confirming diagnosis of OC in the first and second trimesters.

First-trimester assessment of nasal bone using retronasal triangle view: a prospective study.

OBJECTIVE: To examine the feasibility and accuracy of fetal nasal bone (NB) assessment in the retronasal triangle (RNT) view for aneuploidy screening in the first trimester of pregnancy. METHODS: Consecutive women with singleton pregnancies undergoing sonographic screening at 11-13 weeks' gestation were prospectively evaluated. In all cases, assessment of the NB by using the RNT view was attempted and classified as present (if one or both of the NBs were clearly seen) or absent/hypoplastic (if the NB was not visualized or if it was small and less echogenic than the surrounding bones). The detection rate of fetal karyotypic abnormalities by the assessment of the NB in the RNT view was calculated. RESULTS: In total, 1977 women were scanned. The RNT was successfully examined in 1970 fetuses (99.6%). Fetal outcome was available in 1767 (89.7%) of evaluated cases, and of these, 39 (2.2%) cases of aneuploidy were documented (trisomy 21, n=17; trisomy 18, n=8; trisomy 13, n=5; Turner syndrome, n=5; and triploidy, n=4). The prevalence of absent/hypoplastic NB was 12/1728 (0.7%) in chromosomally normal fetuses and 12/17 (70.6%) in trisomy 21 fetuses. Sensitivity, specificity and positive and negative predictive values of absent/hypoplastic NB for trisomy 21 were 70.6%, 99.3%, 50.0% and 99.7%, respectively. The positive and negative likelihood ratios of NB assessment were 101 (95% CI, 53-193) and 0.3 (95% CI, 0.14-0.62), respectively. CONCLUSIONS: The RNT view is a useful technique for assessing the NB during the first trimester of pregnancy. With this new approach, performance of absent/hypoplastic NB as a marker of aneuploidy, mainly trisomy 21, appears to be similar to that previously reported by using the mid-sagittal plane.

Systematic review and meta-analysis of performance of second-trimester nasal bone assessment in detection of fetuses with Down syndrome.

OBJECTIVE: To review systematically the literature on diagnostic tests and performance of second-trimester sonographic assessment of nasal bone (NB) in identifying fetuses affected by Down syndrome. METHODS: A search of studies involving screening tests for NB evaluation and measurements was carried out in the main international bibliographic databases (MEDLINE, EMBASE and CINAHL). Those considered to be relevant were then subjected to critical reading, following Critical Appraisal Skills Programme (CASP) criteria, by at least three independent observers. All data were extracted and tabulated by two independent investigators. A statistical synthesis of sensitivity, specificity and likelihood ratios was performed using specific software (Meta-DiSc). RESULTS: From an initial list of 852 articles referring to ultrasound markers for Down syndrome, 207 relevant papers were selected. Following exclusions, 21 studies were included in the quantitative synthesis. The pooled estimates of positive and negative likelihood ratios were 40.08 (95% CI, 18.10-88.76) and 0.71 (95% CI, 0.64-0.79), respectively, for absent NB and 15.15 (95% CI, 8.15-28.16) and 0.47 (95% CI, 0.34-0.64), respectively, for hypoplastic NB. No relevant differences were found between the various means of defining nasal hypoplasia (multiples of the median (MoM) or percentiles). The biparietal diameter/nasal bone length (BPD/NBL) ratio showed somewhat higher sensitivity but lower specificity with a threshold effect. CONCLUSIONS: NB absence or hypoplasia show high specificity and low but acceptable sensitivity in identifying fetuses with Down syndrome. Screening performance is better with NB measurements as a function of MoM or percentiles rather than as the BPD/NBL ratio. Classification of women into various risk groups for Down syndrome does not affect diagnostic performance.

The usefulness of volume NT software in measuring the fetal nasal bone at 11 to 13 + 6 weeks of gestation.

OBJECTIVE: The objective of this study is to investigate the reproducibility of 3D ultrasound to measure the fetal nasal bone (NB) at first trimester. METHODS: A group of singleton viable pregnancies attending the 11 to 13 + 6 weeks aneuploidy screening at the University of Bologna were prospectively selected. For each patient, fetal NB was measured by 2D ultrasound. Subsequently, a 3D ultrasound of the fetal head was acquired, and fetal NB was measured by offline analysis using the volume nuchal translucency software. The correlation between 2D and 3D ultrasounds and the reproducibility of fetal NB measurement at 3D ultrasound were assessed. RESULTS: Overall, 161 Caucasian women were included in the study. At 3D ultrasound, NB measurement showed an excellent intraobserver [Oper 1, intraclass correlation coefficient (ICC) = 0.98; Oper 2, ICC = 0.921] and interobserver agreement (rc = 0.92). The agreement between 2D and 3D measurements was moderate (rc = 0.77). CONCLUSIONS: A 3D ultrasound supported by the volume nuchal translucency software may provide reliable measurements of the fetal NB in the first trimester.

Cephalometric investigation of craniomaxillofacial structures during the prenatal period: a cadaver study.

INTRODUCTION: We aimed to investigate the morphometric development of the cranial base and its related structures, and their growth rate changes from the ninth gestational week to full term in a large group of human fetuses. METHODS: We selected 203 (109 male, 94 female) fetuses between 9 and 40 weeks of gestation and without any external anomalies. From each fetus, standard lateral and posteroanterior cephalometric images were taken using a dental digital panoramic and cephalometric x-ray machine. Fourteen linear and 9 angular parameters were measured. RESULTS: The cranial base angle showed a statistically significant increase between the groups from only the second to the third trimester periods. The sagittal translation of the maxilla increased during the prenatal period, whereas the mandibular sagittal relation grew at a steady rate. The vertical plane angles of the maxilla and the mandible did not show any significant changes. The maxillary length to mandibular length ratio remained stable. CONCLUSIONS: The cranial base angle increased, especially in the second through the third trimesters. The maxilla and the mandible demonstrated different growth patterns in the sagittal direction. The findings of this study could be a guide for interpreting the relationships among the craniofacial structures.

Fetal nasal bone length at 11(+0) - 13(+6) weeks of gestation: an evaluation of 554 consecutive cases.

PURPOSE OF INVESTIGATION: To develop a nomogram for estimating nasal bone length (NBL) at 11(+0) - 13(+6) weeks of gestation in 554 consecutive cases and to determine the value of NBL measurement in screening for chromosomal abnormalities. MATERIALS AND METHODS: NBL and crown-rump length (CRL) were examined in 554 fetuses at 11(+0) - 13(+6) weeks' gestation. A nomogram for NBL was developed with data from 479 healthy fetuses in which fetal profile examination was possible. Reference values, including percentiles, weie calculated for each gestational age. RESULT: A linear correlation was noted between CRL and NBL in healthy fetuses at 11(+0) - 11(+6), 12(+0) - 12(+6) and 13(+0) - 13(+6) weeks of gestation. Mean NBL was 2.18 +/- 0.53 mm, 2.46 +/- 0.45 mm, and 2.91 +/- 0.55 mm in healthy fetuses, for these time frames, respectively. NBL increased significantly with CRL from respective means of 2.26 +/- 0.43, 2.60 +/- 0.48, 2.77 +/- 0.43, and 3.16 +/- 0.52 mm at 45 - 54.9, 55 - 64.9, 65 +/- 74.9, and 75 - 84 mm. CONCLUSION: The authors developed a NBL nomogram with data from normal, healthy Turkish fetuses at 11(+0) - 13(+6) weeks of gestation. These reference ranges may prove useful in prenatal screening and diagnosis of syndromes known to be associated with nasal hypoplasia.

Nasal bone length: the long and short of it. Evaluation of the reference values for the fetal nasal bone length at 16 to 25 weeks of gestational age in an Indian population.

OBJECTIVE: To establish a reference interval range for the fetal nasal bone length (NBL) in an Indian population. METHODS: A retrospective study of antenatal ultrasound records of fetuses at 16 to 25 weeks in singleton pregnancies. NBL, biparietal diameter (BPD) and femur length were noted in 6436 observations of singleton, euploid, nonmalformed pregnancies. RESULTS: The 50th centile for NBLs increased from 3.4 to 6.9 mm from 16th to 25th week of gestational age. The relation between nasal bone and gestational age, BPD and femur length were found and noted. The NBLs were found to be shorter when compared with other ethnicities. CONCLUSIONS: A reference range for fetal NBLs at 16 to 25 weeks in an Indian population and its relation with fetal biometry was established.

Absent fetal nasal bone: what does it mean for the euploid fetus?

OBJECTIVES: Our purpose was to review the outcomes of singleton pregnancies in which an absent nasal bone was noted on first- or second-trimester sonography and aneuploidy was not present. METHODS: We identified singleton pregnancies from 2005 to 2011 in which an absent nasal bone was noted on sonography, aneuploidy was excluded, and newborn examinations were available for review. Sonographic reports were reviewed for anomalies, growth, and amniotic fluid volume. Newborn records were reviewed for physical examinations, complications, and radiologic or genetic tests. RESULTS: We identified 142 fetuses with a sonographic appearance of an absent nasal bone. We excluded 52 cases with aneuploidy and 33 in which newborn examination information was unavailable. Fifty-seven cases met inclusion criteria. For 3 euploid fetuses with an absent nasal bone on sonography, the presence of additional anomalies on second-trimester sonography ultimately signaled an adverse outcome: the presence of multiple congenital anomalies, a microdeletion syndrome, and a specific genetic diagnosis. CONCLUSIONS: All cases with adverse outcomes had additional prenatal sonographic findings. For the remainder, normal newborn examination findings provide some reassurance, especially in the setting of otherwise normal second-trimester sonographic findings. A microarray as a test for microdeletion and duplication syndromes in this situation could be considered.

Early prenatal diagnosis of orofacial clefts: evaluation of the retronasal triangle using a new three-dimensional reslicing technique.

BACKGROUND: The role of three-dimensional ultrasound in the prenatal diagnosis of orofacial clefts is increasing in recent time. MATERIALS AND METHODS: We obtained three-dimensional data sets of the fetal face from 100 low-risk and 50 high-risk first-trimester fetuses to evaluate the offline reformatting accuracy of the retronasal triangle (RNT) using a novel reslicing technique. RESULTS: Adequate volume data sets for offline analysis were captured in 98% of cases. The RNT view was reformatted in 96% of cases by offline analysis. The secondary palate could be assessed in 93% by offline analysis and an abnormal RNT in the coronal plane was detected in 2 cases of lethal aneuploidy. The false-positive rate was 1.33% in the two studied groups. CONCLUSION: Abnormal RNT seems to be a valuable ultrasound marker for the early diagnosis of facial clefting. This novel reslicing technique has proven to be easy, fast and accurate, which suggest that this technology could be included in daily practice and integrated with other applications such as multiplanar mode and volume NT. Prospective studies are needed to confirm these promising results and to demonstrate if these diagnostic armamentarium tools will lead to a diagnostic enhancement of cleft lip and palate in early pregnancy.

[Investigation of ultrasound markers in screening fetal trisomy 21].

OBJECTIVE: To investigate the clinical value of ultrasound markers in screening fetal trisomy 21. METHODS: From Jan. 2001 to Dec. 2011, a retrospective study about sonographic information of 138 fetuses diagnosed as trisomy 21 was taken in the First Affiliated Hospital of Sun Yat-sen University. All fetuses were divided into 3 groups: isolated ultrasound markers, non-isolated ultrasound markers, and isolated structural malformations or other abnormalities. The relationship between trisomy 21 and ultrasound markers as well as structural anomalies or other abnormalities was analyzed. RESULTS: Sonographic anomalies were detected in 132 fetuses (95.7%, 132/138), including ultrasound markers and structural malformations or other abnormalities. One hundred and twenty cases (87.0%, 120/138) had ultrasound markers, 38 (31.7%, 38/120) had one marker and 82 (68.3%, 82/120) had more than one marker (P < 0.01). Fifty-one fetuses (37.0%, 51/138) had isolated ultrasound markers and non-isolated markers were found in 69 fetuses (50.0%, 69/138). Only 12 fetuses (8.7%, 12/138) had isolated structural malformations or other abnormalities. In 20 fetuses on whom the first-trimester ultrasound screening were performed, all had ultrasound markers, 95% (19/20) had thickened nuchal translucency and 55% (11/20) had nasal bone hypoplasia. The most common ultrasound markers on the second-trimester screening were nasal bone hypoplasia, which accounted for 41.9% (52/124) cases, followed by thickened nuchal fold (25.0%, 31/124), short femurs and humerus (24.2%, 30/124), echogenic intracardiac focus (16.1%, 20/124), mild ventriculomegaly (15.3%, 19/124), hyperechoic bowel (12.9%, 16/124), mild renal pyelectasis (12.1%, 15/124). Furthermore, the common structural malformations or other abnormalities were as follows: cardiac defects (33.1%, 41/124), digestive system (26.6%, 33/124). CONCLUSIONS: Ultrasound markers are valuable for screening fetal trisomy 21. The fetuses of trisomy 21 usually had more than one ultrasound markers or associated with other abnormalities. Combinations of ultrasound markers with the results of serum screening and maternal age are necessary for evaluation.

[Study on several ultrasound markers combined maternal serum biochemical markers to screen fetal chromosomal aneuploidy at 11 to 13(+)6 weeks of gestation].

OBJECTIVE: To evaluate the efficiency of combined screening for chromosomal abnormalities in the first trimester and the ultrasound characteristics of these fetuses. METHODS: Retrospective study for 5000 singleton pregnancies by combined screening of trisomies 21, 18, 13 and Turner syndrome.Risk algorithms were developed for calculation of patient-specific risks for each of the three trisomies based on maternal age, fetal nuchal translucency, free ß human chorionic gonadotropin and serum pregnancy associated plasma protein A at 11 to 13(+6) weeks of pregnant. The value of nuchal translucency (NT) and ß-hCG and pregnancy-associated plasma protein A (PAPP-A) level were inputted computer, and calculate the risk value ( ≥ 1: 270) by automatic analysis software. Two hundred and four cases with high risk were performed transabdominal chorionic villus biopsy to detect the fetal chromosomal karyotypes. Meanwhile, other ultrasonic characteristics of fetal were elevated. RESULTS: (1) Five thousand cases of pregnant women were detected, including 4983 normal cases, 62 cases were induced labor for a variety of reasons in the second trimester, including 40 cases with normal karyotype but with congenital heart disease, 17 cases of chromosome abnormalities (9 cases trisomy 21, 2 cases trisomy 18, 1 cases trisomy 13, 4 cases 45X), 2 cases spina bifida, 2 cases digestive tract obstruction, 1 cases giant bladder.One case with low risk of fetal chromosomal abnormalities in combined screening, but high risk of age (maternal age were over 40 years old), it was 21 trisomy syndrome after the prenatal diagnosis.(2) Five cases of nasal bone loss in 9 cases of trisomy 21 (5/9), 5 cases with three tricuspid regurgitation (5/9), 4 cases of venous ductus a wave flow reverse (4/9), 3 cases of fetal nasal bone loss accompanied by tricuspid regurgitation and venous ductus a wave flow reverse (3/9).One case of nasal bone loss in 2 cases of trisomy 18, 2 cases were tricuspid regurgitation and venous ductus a wave flow reverse. Two cases in 4 cases of 45X had venous ductus a wave flow reverse. There were 8 cases (0.16%) nasal bone absence in 4983 cases of normal karyotype fetus, 48 cases (0.96%) of tricuspid regurgitation and 44 cases (0.88%) of venous ductus a wave flow reverse. Thirty-two cases in 40 cases (80%) of fetal congenital heart disease were tricuspid regurgitation, 30 cases of venous ductus a wave flow reverse (75%).Eight cases of nasal bone absence normal karyotype fetus were found the nasal bone at 20 weeks gestation. CONCLUSION: Combination screening of nuchal translucency with serum markers in the first trimester were high detection rate and low false positive rate; a wave reversion and fetal nasal bone absence accompanied by tricuspid regurgitation can improve the detection rate of abnormal karyotype; abnormalities ultrasound marker may be associated with fetal congenital heart disease at 11-13(+6) weeks of pregnancy.

Second-trimester soft markers: relation to first-trimester nuchal translucency in unaffected pregnancies.

OBJECTIVE: Genetic sonography following first-trimester combined screening appears to increase substantially detection rates for Down syndrome but it relies on the unproved assumption of independence between these tests. In this study we aimed to investigate the relationship between first-trimester nuchal translucency (NT) and a series of second-trimester soft markers and structural defects in unaffected pregnancies. METHODS: NT measurement in the first trimester was followed by second-trimester scan (18 to 23 + 6 weeks) including examination for three categorical markers (intracardiac echogenic foci, hyperechogenic bowel and structural defects) and measurement of nasal bone length, nuchal-fold thickness, femur length, humerus length, renal pelvis diameter and prenasal thickness. All continuous variables were expressed in multiples of the median (MoM) for gestation and correlation coefficients between log-transformed NT and second-trimester variables were calculated. In addition, frequencies of soft markers and structural defects in cases with increased NT were compared to those with normal NT, using MoM cut-offs. RESULTS: In a dataset of 1970 cases, NT was significantly correlated (P < 0.05) with all second-trimester continuous variables, the correlation being strongest for nuchal-fold thickness (r = 0.10). There was a higher frequency of cases with second-trimester nuchal-fold thickness above the 97.5(th) centile (10.7 vs. 2.2%) and hyperechogenic bowel (2.4 vs. 0.1%) in cases with increased NT. CONCLUSIONS: Straightforward reassessment of risk using likelihood ratios derived from the second-trimester genetic sonogram might lead to inaccurate estimates. Multivariate models using continuous second-trimester variables might be preferable in sequential screening strategies.

Three-dimensional ultrasound imaging and measurement of nasal bone length, prenasal thickness and frontomaxillary facial angle in normal second- and third-trimester fetuses.

OBJECTIVES: To assess the feasibility of nasal bone length (NBL), prenasal thickness (PT) and frontomaxillary facial (FMF) angle measurements performed on the same three-dimensional (3D) multiplanar-corrected profile view in healthy second- and third-trimester fetuses, to create reference ranges and to review published measurement techniques. METHODS: 3D volumes of 219 healthy second- and third-trimester fetuses were retrospectively analyzed. The quality of images and measurability of the markers were assessed with 5-point and 3-point scoring systems, respectively. Measurements of NBL (with care to exclude the frontal bone), PT and FMF were obtained in the exact mid-sagittal plane. Reference ranges were constructed based on measurements from images with high-quality (4 or 5 points) and high measurability (2 or 3 points) scores and compared with those in the most relevant published literature. RESULTS: A high-quality score was assigned to 111 images. Among these, a high measurability score was significantly more often achieved for NBL (98.2%) and PT (97.3%) than for the FMF angle (26.1%) (P < 0.001). Both NBL (NBL = - 6.927 + (0.83 × GA) - (0.01 × GA(2))) and PT (PT = (0.212 × GA) - 0.873) (where GA = gestational age) showed growth with gestation, with less pronounced growth for NBL after 28 weeks. Our reference range for the NBL showed a systematically smaller length than those in other two-dimensional (2D) ultrasound-based publications. The FMF angle measurements that we obtained did not show a significant change with GA. CONCLUSIONS: NBL and PT are easily measured using 3D ultrasound whereas FMF angle measurement is more challenging. When it is measured in the exact mid-sagittal plane and care is taken to exclude the frontal bone, measurements of the NBL are systematically smaller than those in previous 2D ultrasound-based publications.

Aberrant right subclavian artery: incidence and correlation with other markers of Down syndrome in second-trimester fetuses.

OBJECTIVE: To assess the incidence of aberrant right subclavian artery (ARSA) and other strong markers of Down syndrome and their correlation in a large population of second-trimester Down syndrome fetuses assessed in a tertiary referral center. METHODS: Presence or absence of ARSA and other major ultrasound markers of Down syndrome was assessed in a population of 106 second-trimester Down syndrome fetuses referred to our unit for expert assessment and/or termination of pregnancy after karyotyping performed for positive first- or second-trimester screening or advanced maternal age or on maternal request. All cases in which the diagnosis of Down syndrome followed the ultrasound detection of major anomalies or soft markers were excluded from the study, as were all cases with a gestational age less than 14 + 0 weeks. We searched for the ARSA on the three vessels and trachea view using color or power Doppler. All fetuses underwent a thorough anatomic assessment and fetal echocardiography. The other Down syndrome markers assessed were: absent or hypoplastic nasal bone (NB-), defined as length < 5(th) centile; nuchal fold ≥ 5 mm; and mild pyelectasis (> 5 mm). In addition, the presence of major cardiac and extracardiac defects was recorded. A correlation analysis was then performed in order to investigate possible associations between markers and/or major anomalies. Postmortem or postnatal diagnostic confirmation was available in all cases. RESULTS: The mean (SD) gestational age at ultrasound assessment was 20.4 (4.1) weeks. The incidence of the various variables in the population of Down syndrome fetuses was: ARSA, 25%; NB-, 43%; nuchal fold ≥ 5 mm, 16%; pyelectasis, 17%; major heart defects, 41%; atrioventricular septal defect, 25%; and extracardiac anomaly, 24%. The presence of ARSA did not correlate with any of the other variables. The only positive correlations (P < 0.05) were between NB- and pyelectasis, and between cardiac and extracardiac defects. CONCLUSIONS: This represents the largest Down syndrome population assessed for ARSA. In this series, the incidence of ARSA was 25%, lower than previously reported in much smaller series. Its presence did not correlate with the presence of any other marker or major anomaly, including heart defects.