Technical factors influencing sonographic visualization of fetal echogenic intracardiac foci

PURPOSE: A fetal echogenic intracardiac focus (EIF) is most commonly a normal variant in a normal fetus, but owing to reports of an increased risk of aneuploidy with EIFs, the finding causes concern when noted on routine obstetric sonograms. This study was undertaken to determine which factors influence the sonographic visualization of fetal EIFs. METHODS: In part 1 of the study, records from 1,920 fetal sonographic examinations were reviewed for fetal age, indication for sonography, and abnormal findings. For all cases with EIFs recorded and 645 randomly selected cases with no record of EIFs, sonograms were reviewed for heart position at the time of the 4-chamber view, technologist performing the examination, fetal position, heart visibility, transducer frequency, machine type, amount of amniotic fluid, and presence/absence of an EIF. In part 2 of the study, machine settings were evaluated with respect to visualization of EIFs. RESULTS: In part 1 of the study, only the technologist performing the examination and the fetal position were associated with visualization of EIFs. In part 2 of the study, we found that the standard obstetric mode settings are better for visualization of EIFs than are the fetal echocardiographic mode settings. CONCLUSIONS: We conclude that technical factors influence visualization of EIFs.     

Isolated sonographic markers for detection of fetal Down syndrome in the second trimester of pregnancy.

OBJECTIVE: To determine whether sonographic "markers" are associated with fetal Down syndrome during the second trimester and to estimate the degree of risk of individual markers using likelihood ratios. METHODS: Second-trimester (14-20 weeks) sonographic findings in 186 fetuses with trisomy 21 were compared with a control group of 8728 consecutive control fetuses. Six markers were evaluated: nuchal thickening, hyperechoic bowel, shortened femur, shortened humerus, echogenic intracardiac focus, and renal pyelectasis. RESULTS: Major or structural abnormalities were observed in 31 fetuses with trisomy 21 (16.7%) and 53 control fetuses (0.6%) (P< .001). Some type of sonographic finding (major abnormality, minor marker, or both) was observed in 68.8% of fetuses with trisomy 21 compared with 13.6% of control fetuses (P < .001). An isolated minor or "soft" marker was the only sonographic finding in 42 (22.6%) of 186 fetuses with trisomy 21 compared with 987 (11.3%) of 8728 control fetuses (P < .001). Nuchal thickening (P < .001; likelihood ratio, 11) and hyperechoic bowel (P < .001; likelihood ratio, 6.7) showed the strongest association with trisomy 21 as isolated markers, followed by shortened humerus (likelihood ratio, 5.1), echogenic intracardiac focus (likelihood ratio, 1.8), shortened femur (likelihood ratio, 1.5), and pyelectasis (likelihood ratio, 1.5). Echogenic intracardiac focus was the single most common isolated marker in both affected fetuses (7.1%) and control fetuses (3.9%) but carried a low risk (P= .046; likelihood ratio, 1.8). CONCLUSIONS: A single soft marker is commonly encountered during the second trimester among fetuses with trisomy 21. The risk of fetal Down syndrome, reflected by likelihood ratios, was determined for 6 individual markers. This information can be combined with the a priori risk to estimate the individual patient risk for fetal Down syndrome.     

Ethnicity and other factors that may affect the prevalence of echogenic intracardiac foci in the fetus

PURPOSE: To study ethnicity and other possible factors that may affect the incidence of echogenic intracardiac foci (EIF) when detected via sonographic examination. MATERIALS AND METHODS: Patients were referred to our institution for sonographic evaluation from a wide range of practice formats, including both private obstetric practices as well as community outpatient clinics. The study protocol included presence or absence of EIF, maternal age, ethnicity, gestational age during the examination, optimal versus suboptimal scans, presence of other fetal malformations and sonographic markers, and presence of chromosomal anomalies. Fetal outcome was ascertained in 90% of the study group. For statistical analysis, the chi-square test and the Student t-test were used. RESULTS: The study group included 1,543 patients who had a fetal anatomy survey between 16 and 24 weeks' gestation. The prevalence of EIF was similar in all 4 ethnic groups (Asian, Hispanic, black, and white). There were 76 cases of EIF-an overall prevalence of 4.9%. Seventy-one of these cases were isolated in the left ventricle, 2 were isolated in the right ventricle, and 3 showed multiple foci. The prevalence of EIF was similar between younger and older patients, early and late gestational age at the time of sonographic examination, and optimal and suboptimal sonograms. Fetuses with EIF had significantly more congenital anomalies and other sonographic markers compared with fetuses without EIF. CONCLUSIONS: We did not find any significant difference in the prevalence of EIF among the 4 different ethnic groups. The association between congenital anomalies and other sonographic markers should be studied further.     

Second‐Trimester Genetic Sonography After First‐Trimester Combined Screening for Trisomy 21

Objective. The purpose of this study was to evaluate the trisomy 21 screening performance of the first‐trimester combined test followed by second‐trimester genetic sonography. Methods. This retrospective cohort study included all women with singleton pregnancies undergoing combined screening followed by genetic sonography at 17 to 21 weeks from January 1, 2005, to January 31, 2008. Combined test trisomy 21 risks were multiplied by positive or negative likelihood ratios based on the second‐trimester sonographic findings to determine the final trisomy 21 risk. Sonography was evaluated as the second part of (1) a stepwise sequential test applied to combined screen‐negative pregnancies and (2) an integrated test applied to all combined screen patients regardless of the latter results. A final trisomy 21 risk of 1:270 or higher was considered screen‐positive. Results. A total of 2231 pregnancies underwent combined screening, which detected 7 of 8 Down syndrome cases (87.5%) at a 9.6% screen‐positive rate. A total of 884 of these patients (39.6%), including 2 having fetuses with Down syndrome, had genetic sonography. Combined screening detected 1 of these trisomy 21 fetuses (50%) at a 15.7% screen‐positive rate. Integrated ultrasound‐based aneuploidy screening detected both trisomy 21 cases (100%) at a 22.7% screen‐positive rate, whereas stepwise sequential ultrasound‐based aneuploidy screening also detected both trisomy 21 fetuses (100%) but at a 28.3% screen‐positive rate (P < .0001). Conclusions. Second‐trimester genetic sonography after first‐trimester combined screening may improve trisomy 21 detection at the expense of increasing screen‐positive rates.     

An isolated echogenic heart focus is not an indication for amniocentesis in 12,672 unselected patients.

OBJECTIVE: To evaluate the risk of Down syndrome in fetuses with a heart echogenic focus using the Bayes theorem and likelihood ratios in an unselected population. METHODS: We prospectively evaluated 12,672 second-trimester sonographic features and extracted and examined a population with an echogenic focus for chromosomal anomalies. RESULTS: There were 479 cases of echogenic focus; 90.4% were isolated, whereas 9.6% had associated findings. Eleven patients had fetuses with trisomy 21 (9 per 10,000). Eight of those did not have an echogenic focus, whereas 3 had a heart echogenic focus. Only 1 fetus with trisomy 21 had an isolated echogenic focus. The positive likelihood ratio for total cases of a heart echogenic focus and trisomy 21 was 7.25, whereas for an isolated echogenic focus, the positive likelihood ratio was 2.66. CONCLUSIONS: The results of the statistical analysis showed that the risk of aneuploidy is increased in fetuses with an echogenic intracardiac focus; however, the finding should prompt a detailed structural survey and correlation with a priori risk. Amniocentesis need not be offered to patients who are otherwise at low risk and have an isolated echogenic intracardiac focus.     

Significance of an echogenic intracardiac focus in fetuses at high and low risk for aneuploidy.

Our objective was to evaluate the significance of an echogenic intracardiac focus in a mixed population of fetuses at high and low risk for aneuploidy. Over a 1 year period, we prospectively identified all fetuses with an echogenic intracardiac focus seen during prenatal sonography. A detailed structural evaluation was performed on each fetus as permitted by gestational age. The location and number of foci were tabulated prospectively, as were associated abnormalities. Follow-up was obtained by review of the medical record. Of the 290 fetuses who had an echogenic intracardiac focus, 14 of them were aneuploid (4.8%). Of the 290 mothers, 125 women were aged 35 years or older and 165 women were younger than 35 years old. Among the 125 fetuses born to women 35 years or older, eight were aneuploid fetuses (6.4%), while among the 165 fetuses of younger mothers, six were aneuploid fetuses (3.6%) (rate ratio = 1.8; 95% confidence interval [extremes] = 0.6, 4.9). Only one of the 14 aneuploid fetuses had an echogenic intracardiac focus as the only sonographic finding, and this occurred in a woman aged 41 years. The majority of the echogenic intracardiac foci (87.6%) were located in the left ventricle, while 4.8% of the foci were right-sided and 7.6% were bilateral. Among the 14 aneuploid fetuses, 14% had bilateral echogenic intracardiac foci and 7% had right-sided foci. Among the euploid fetuses, 7.3% had bilateral echogenic intracardiac foci and 4.7% had right-sided foci. In conclusion, we have shown that the presence of an echogenic intracardiac focus does raise the risk that the fetus has a chromosomal abnormality, most commonly Down syndrome, although all but one aneuploid fetus in our study had other sonographic findings.     

Relationship of isolated fetal intracardiac echogenic focus to trisomy 21 at the mid-trimester sonogram in women younger than 35 years.

OBJECTIVE: To determine whether an isolated echogenic intracardiac focus in the fetal heart in the mid-trimester (16-24 weeks) in women aged 18-34 years of age is associated with trisomy 21. METHOD: This was a prospective population-based observational study. A search of all obstetric sonograms performed in our region from January 1997 to December 1999 was carried out. From 12,373 pregnancies we identified 267 cases of echogenic foci in the fetal heart. Trisomy 21 was detected in 38 deliveries (0.31%). An echogenic focus was seen in 193 of the 9167 women < 35 years of age who had an obstetric sonogram at 16-24 weeks' gestation, and an echogenic focus was seen in 67 of the 1968 women > 35 years. The study group comprised the 149 women aged 18-34 years who had an echogenic focus in the fetal heart as the only abnormality at an obstetric sonogram performed at 16-24 weeks' gestation. RESULTS: There were no abnormal outcomes or cases of trisomy 21 among the 149 pregnancies with an echogenic focus as an isolated finding in women aged 18-34 years (0% (95% confidence interval, 0.00-2.43)). The prevalence of isolated echogenic focus was 1.6% for women < 35 and 1.8% for women >or= 35 years old. Of the 25 fetuses with trisomy 21 undergoing an obstetric sonogram at any gestational age, five (20%) had an echogenic focus. An isolated echogenic focus was present in one fetus with trisomy 21 seen at 26 weeks' gestation in a 17-year-old mother. Echogenic foci were single and in the left ventricle in 84.7% of cases. CONCLUSION: An isolated echogenic focus in the fetal heart at mid-trimester ultrasound in women aged 18-34 years is not associated with increased risk for trisomy 21.     

The value of single umbilical artery in the prediction of fetal aneuploidy: findings in 12,672 pregnant women

OBJECTIVES: To assess the risk of the association of single umbilical artery and aneuploidies. METHODS: In a general unselected obstetric population of 12,672 singleton pregnant women from January 1998 to December 2002, we detected 61 fetuses (prevalence, 0.48%) with single umbilical artery (SUA) on prenatal ultrasound at 16 to 23 menstrual weeks. RESULTS: Among the 61 fetuses with 2-vessel cord, 39 (64%) had SUA as an isolated finding, and 22 (36%) had additional findings, either minor or major. One (2.56%) of the 39 fetuses with SUA as an isolated finding had aneuploidy (trisomy 21 at maternal age of 32 years), whereas 5 (41.6%) of the 12 fetuses with SUA concomitant with major anomalies were aneuploid. None of the 10 fetuses with SUA and minor anomalies had aneuploidy. Among the 12,611 women with 3-vessel cord, we instead found 8 cases of trisomy 21 (0.06%), 1 case of translocation 14-21 (0.007%), 5 cases of trisomy 18 (0.04%), 1 case of trisomy 13 (0.007%), 1 case of 47,XXX (0.007%), and 2 cases of monosomy X (0.01%). CONCLUSIONS: In an unselected population, second trimester sonographic detection of SUA and major fetal anomalies indicate increased risk for fetal aneuploidy. However, even if this study is based on a large population, the only 1 case of trisomy 21 among the fetuses with SUA as an isolated finding is not sufficient to draw a conclusion, and larger studies are needed to confirm or infirm this single case.     

Comparison of Single Versus Multiple Echogenic Foci in the Fetal Heart Regarding Risk of Aneuploidy

Objective. The purpose of this study was to investigate whether multiple echogenic cardiac foci (ECF) are associated with an increased risk of fetal trisomy 21 in our patient population. Methods. During a span of 38 months, all women found to have an ECF on obstetric sonography were identified as study patients and grouped into single‐ and multiple‐ECF groups. Age‐ and race‐matched patients were identified as a control group. Fetal anatomic sonographic examinations were assessed for other markers of aneuploidy and major abnormalities. The baseline risk for trisomy 21 was assessed by maternal serum screening or age alone if no serum screening had been performed. Trisomy 21 was assessed by amniocentesis or clinically at birth. Both univariate and multivariate analyses were used to assess for associations with trisomy 21. Results. Six of 71 patients (8.5%) with multiple ECF and 1 of 171 patients (0.6%) with a single ECF had trisomy 21. One of 242 control patients (0.4%) had trisomy 21. Logistic regression found multiple ECF (P < .008), the presence of a major finding or multiple minor findings (P = .0012), and a baseline risk for trisomy 21 of greater than 1 in 100 (P = .003) as independent associations with trisomy 21. Conclusions. Our results suggest that finding multiple ECF is a stronger predictor of trisomy 21 than what is described for a single ECF.     

Ultrasound detection and perinatal outcome of fetal trisomies 21, 18 and 13 in the absence of a routine fetal anomaly scan or biochemical screening.

OBJECTIVES: To determine the prenatal detection rate of abnormality (fetal anomaly or growth restriction) in pregnancies complicated by fetal trisomies 21, 18 and 13 in an obstetric population managed without routine biochemical or sonographic screening tests and to assess the perinatal outcome of these pregnancies. SUBJECTS AND METHODS: This was a retrospective analysis of obstetric and neonatal data pertaining to infants born with trisomy 21, 18 or 13 (n = 82) diagnosed between 1989 and 1997 (23 762 deliveries). RESULTS: Antenatal suspicion of aneuploidy, based on the detection of growth restriction or fetal anomaly, was present in 18.3% (11 of 60) of fetuses with trisomy 21, in 81.2% (13 of 16) of fetuses with trisomy 18, and in 83.3% (five of six) of fetuses with trisomy 13. The antenatal detection rates for growth restriction were accurate whereas the antenatal detection rates for fetal anomalies were poor. Intrauterine fetal death occurred in 18.8% of fetuses with trisomy 18 (three of 16) and in 50% (three of six) of cases of trisomy 13. For babies born alive with trisomy 18 or 13 the neonatal mortality was 93.8% (15 of 16). All cases of trisomy 21 fetuses survived beyond the perinatal period and the antepartum and intrapartum details of these pregnancies were unremarkable. CONCLUSION: In obstetric practice without routine biochemical or sonographic screening tests the detection of findings suggestive of aneuploidy is low for trisomy 21, but is high for trisomies 18 and 13. These findings provide information for counseling about the antenatal, intrapartum, and neonatal course of these trisomies.     

The association of aneuploidy and mild fetal pyelectasis in an unselected population: the results of a multicenter study.

INTRODUCTION: Mild pyelectasis is a common finding and there is some debate as to its association with aneuploidy. The results of a large, prospective, multicenter study of mild pyelectasis designed to determine the incidence and association with aneuploidy in an unselected population are reported. METHODS: A large multicenter, prospective observational study of unselected fetuses with mild pyelectasis identified between 16 and 26 weeks' gestation in routine ultrasound departments. RESULTS: There were 737 fetuses with mild pyelectasis of which 12 had an abnormal karyotype. Pyelectasis was isolated in three fetuses with Down syndrome, but in one the mother was older (36 years). CONCLUSION: These data confirm the fact that the presence of mild fetal pyelectasis increases the risk for aneuploidy, in particular trisomy 21. However, other risk factors should be considered before embarking on fetal karyotyping, as for most pregnancies complicated by isolated mild pyelectasis, risks of aneuploidy will remain small.     

Sonographic markers of fetal trisomies: second trimester.

OBJECTIVE: Second-trimester sonographic findings of fetal trisomy may include structural abnormalities or sonographic markers of fetal aneuploidy. Unlike structural anomalies, sonographic markers of fetal aneuploidy are insignificant by themselves with regard to outcome, are nonspecific--most frequently seen in normal fetuses, and are often transient. Our objective was to review the second-trimester sonographic findings of the major trisomic conditions, trisomies 13, 18, and 21. METHODS: We reviewed a number of the most commonly accepted markers, including nuchal thickening, hyperechoic bowel, echogenic intracardiac focus, renal pyelectasis, shortened extremities, mild cerebral ventricular dilatation, and choroid plexus cysts. Markers associated with trisomy 21 were emphasized. RESULTS: The sensitivity of sonography for detection of fetal trisomic conditions varies with the type of chromosome abnormality, gestational age at the time of sonography, reasons for referral, criteria for positive sonographic findings, and the quality of the sonography. As an estimate, 1 or more sonographic findings can be identified in approximately 90% of fetuses with trisomy 13, 80% of fetuses with trisomy 18, and 50% to 70% of fetuses with trisomy 21 (Down syndrome). CONCLUSIONS: The presence or absence of sonographic markers can substantially modify the risk of fetal Down syndrome and is the basis of the so-called genetic sonogram. Because maternal biochemical and sonographic markers are largely independent, combined risk estimates will result in even higher detection rates than either alone.     

胎儿心腔内微小强回声灶的临床意义

目的探讨胎儿心脏内强回声灶（EIF）的临床意义。方法用胎儿超声心动图检测正常孕妇的胎儿6694例，并与畸形胎儿或染色体异常胎儿EIF发生率进行比较，对胎儿EIF进行随访。结果①正常孕妇人群中胎儿EIF发生率为0．73％，与畸形胎儿或染色体异常胎儿EIF发生率1．61％，比较没有明显统计学意义（P〉0．05）；②〈35岁孕妇与≥35岁孕妇，其胎儿EIF发生率没有明显统计学差异（P〉0．05）。结论对于发现单纯胎儿EIF而没有合并心内或其他畸形，ElF并没有太多的临床意义，仅能作为提示胎儿畸形或染色体异常的筛选线索。     

A preliminary study of sonographic grading of fetal intracardiac echogenic foci: feasibility, reliability and association with aneuploidy.

OBJECTIVES: To prospectively and quantitatively grade intracardiac echogenic focus/foci (ICEF) using sonographic gain reduction and to determine the association of ICEF by grade with fetal aneuploidy. METHODS: Women referred for raised maternal age (> or = 35 years), or > 18 years of age and with a Down syndrome risk > or = 1/270, increased trisomy 18 risk by second trimester serum screen or a prior aneuploid offspring were included in this institutionally approved protocol. Only pregnancies of gestational age between 14 and 24 weeks were included. All women had a targeted ultrasound and were offered fetal chromosome analysis. The classification of ICEF was made from a four-chamber view of the fetal heart. The echo amplitude of the ICEF was compared to that of the thoracic spine and categorized according to the comparative gain setting at which the image of the relevant structure disappeared: Grade O = no ICEF present, Grade 1 = ICEF image lost before thoracic spine when gain was reduced, Grade 2 = ICEF image lost at same gain setting as thoracic spine, Grade 3 = thoracic spine image lost before ICEF. The primary outcome was a prenatally or post-natally detected chromosomal abnormality. RESULTS: A total of 885 eligible women were examined during the 21-month study period. ICEF were seen in 29 (3.3%) fetuses: 24(83%) in the left ventricle and five (17%) in the right ventricle. A chromosome abnormality was identified in 13/671 (1.9%) fetuses without ICEF (Grade 0) and 0/21 (0%) fetuses with Grade 1 ICEF. In contrast, two of five (40%) fetuses with Grade 2 ICEF were aneuploid (P = 0.005). No Grade 3 ICEF were observed. Additional sonographic abnormalities were seen in both aneuploid fetuses with Grade 2 ICEF. Interobserver agreement on ICEF grading was noted in 50/50 (100%) examinations (kappa = 1.0). CONCLUSIONS: Sonographic grading of ICEF is feasible and highly reliable. Grade 2 ICEF, especially when accompanied by additional sonographic markers of a chromosomal abnormality, are associated with aneuploidy significantly more frequently than Grade 1 ICEF.     

Ultrasonographic markers for chromosomal abnormalities in women with negative nuchal translucency and second trimester maternal serum biochemistry.

OBJECTIVE: To analyze the value of second trimester ultrasound examination among those women whose fetuses were indicated to be at low risk of chromosomal anomalies on the basis of both first trimester nuchal translucency measurement and second trimester biochemical screening. METHODS: A retrospective study of 5500 pregnancies carried out at the fetal medicine unit, Royal Free Hospital. During a period of over 3 years 5500 pregnancies underwent a first trimester scan and nuchal translucency measurement which enabled the detection of 62% (20 of 32) of all chromosomal anomalies. From the remaining pregnancies that underwent second trimester biochemical screening, 3548 were considered negative (risk < 1:250; using maternal serum free beta human chorionic gonadotrophin and alpha fetoprotein). The ultrasound markers that were examined were: shortened femur length, echogenic bowel, pyelectasis, choroid plexus cysts and echogenic intracardiac foci. The likelihood ratios for chromosomal aneuploides for each of these markers were calculated. RESULTS: Of the 3548 screen negative pregnancies, 3541 (99.8%) had a normal karyotype. Seven (0.2%) fetuses had an abnormal karyotype including four (0.11%) with trisomy 21, one with trisomy 18 and two with 47XXY. Second trimester ultrasound markers were found in two of the five (40%) with severe chromosomal anomalies compared to 184 of 3541 (5.2%) with normal karyotypes. Detection of one or more ultrasound markers in a screen negative pregnancy increased the possibility of chromosomal aneuploidy and a negative ultrasound decreased the risk by a likelihood ratio of 0.6 (95% confidence interval, 0.3-1.3). The risk was considerably increased when two or more markers were detected and we would recommend karyotyping under these circumstances. CONCLUSION: This preliminary data indicates a possible role for abnormal ultrasound markers in assessing the risk of chromosomal abnormalities in patients considered to be at low risk by nuchal translucency and serum screening. However analysis of a much larger study group will have to be conducted to assess the significance of individual markers.     

Ethnic variation in the prevalence of echogenic intracardiac foci and the association with Down syndrome.

OBJECTIVE: To determine whether the prevalence of fetal echogenic intracardiac foci (EIF) differs according to maternal ethnicity. METHODS: We performed a retrospective cohort study of all women undergoing second-trimester diagnostic ultrasound examination and amniocentesis at a prenatal diagnosis referral center from January 1 2000 to July 1 2003. Data were collected on the presence of EIF, gestational age at time of ultrasound scan, karyotype results, maternal age and ethnicity. Univariate and multivariate analyses of EIF, ethnicity and presence of aneuploidy were conducted. RESULTS: Among the 7480 women qualifying for the study, EIF were found in 309 (4.1%). When maternal ethnicity was subdivided into Caucasian, African-American, Hispanic, Asian-American, Native American, Asian Indian, and Middle Eastern, the highest rates of EIF were found in fetuses of African-American (6.7%), Asian-American (6.9%), and Middle Eastern (8.1%) mothers compared to a rate of 3.3% in Caucasians (P < 0.001). In all ethnic groups except Hispanics, EIF was associated with an increased risk for Down syndrome (odds ratio range from 1.8 to 15.7). CONCLUSIONS: African-American, Asian-American, and Middle Eastern patients are more likely than patients of other ethnicities to have a fetus with an EIF. Even controlling for ethnicity, fetuses with an EIF still have an increased risk for Down syndrome. As more data accumulate, the prevalence of EIF and its association with Down syndrome among different ethnic groups can be incorporated into patient counseling.     

Role of First‐Trimester Sonography in the Diagnosis of Aneuploidy and Structural Fetal Anomalies

Objective. We sought to determine the sensitivity of the first‐trimester scan in the early diagnosis of aneuploidy and structural fetal anomalies in an unselected low‐risk population. Methods. This was a retrospective chart review of all patients having first‐trimester scans between 2002 and 2009. At our center, a survey of fetal anatomy is performed at the time of nuchal translucency assessment at 11 weeks to 13 weeks 6 days. A second‐trimester scan is done at 20 to 23 weeks and a third‐trimester scan at 32 to 35 weeks. Isolated sonographic findings of choroid plexus cysts and echogenic intracardiac foci were excluded. Lethal anomalies and those requiring immediate surgical intervention at birth were considered major structural anomalies. All scans were performed by a single sonologist certified by the Fetal Medicine Foundation. All neonates were examined at birth by a pediatrician. Results. Our study included 1370 fetuses. Six cases of aneuploidy (0.4%) were detected. The first‐trimester scan detected 5 of 6 cases of aneuploidy (83%), confirmed by karyotype. There were 36 cases of structural fetal anomalies (2.6%); 20 (1.5%) were major anomalies. The first‐trimester scan detected 16 of 36 (44%); 20 (56%) were identified by second‐ or third‐trimester scans. The first‐trimester scan detection rate for major structural anomalies was 14 of 20 (70%). The 5 that were missed by the first‐trimester scan were detected by a second‐trimester scan. Conclusions. Our study emphasizes the importance of the first‐trimester scan in the early detection of aneuploidy and structural fetal anomalies. In this small unselected low‐risk population, the first‐trimester scan detected 83% of aneuploidies and 70% of major structural anomalies. Our results are comparable to previously published studies from other centers and further exemplify the invaluable role of the first‐trimester scan in the early detection of aneuploidy and structural anomalies in an unselected low‐risk population.     

Detection of sonographic markers of fetal aneuploidy depends on maternal and fetal characteristics.

OBJECTIVES: The purpose of this study was to determine factors that influence the detection rate of sonographic markers of fetal aneuploidy (SMFA). METHODS: We reviewed the sonographic images of 160 consecutive second-trimester trisomic fetuses for the presence of SMFA, either structural anomalies or sonographic soft markers. RESULTS: One hundred forty-nine (93.1%) records were complete and analyzed; 78 cases (52.3%) were identified with 1 or more SMFA. Sonographic markers of fetal aneuploidy were detected in 42.7%, 75.0%, and 90.9% of trisomies 21, 18, and 13, respectively (P<.005). The detection rate of SMFA had a positive linear correlation with gestational age (adjusted R(2)=0.64; P<.002). Sonographic markers of fetal aneuploidy were detected in 43.7% of fetuses of less than 18.0 weeks' gestation and 64.5% of fetuses of 18.0 weeks' gestation or greater (likelihood ratio=6.4; P<.01). Sonographic markers of fetal aneuploidy were detected in 23.5% of patients with suboptimal image quality versus 58.3% of the others (likelihood ratio=7.5; P<.05). The rate of structural malformation was similar between the male and female fetuses, whereas that of soft markers was 49.4% in male and 30.0% in female fetuses (odds ratio=2.3; range, 1.2-4.5; P<.02). Factor analysis showed that some soft markers and some structural anomalies tended to appear together. CONCLUSIONS: The type of fetal trisomy, gestational age, sex, and quality of images influence the detection rate of SMFA. The highest detection rate for SMFA in the second trimester is at or above 18 weeks' gestational age. Certain markers are detected in clusters. These findings may explain, in part, the variability in reported rates of detection of SMFA among trisomic fetuses. These findings need to be prospectively tested in the general population of pregnancies for applicability to sonographic risk calculations for fetal trisomies.     

Dilated intracranial translucency and blake's pouch cyst: First‐trimester ultrasound markers of occipital cephalocele diagnosed using novel three‐dimensional reslicing technique

Abnormal intracranial translucency (IT) (fourth ventricle) and a Blake's pouch cyst with normal brain stem cavity may be valuable first‐trimester call signs of defects in the skull base. Here, we report a case of presumptive two‐dimensional sonographic diagnosis of occipital cephalocele that was posed at the time of 11–13 weeks aneuploidy scan. The two‐dimensional sonographic finding elicited a detailed fetal neuroscan that was performed using either multiplanar mode or a novel three‐dimensional reslicing and lightening technique. The use of three‐dimensional sonographic software and offline “navigation” within the volume of interest enabled operators to capture a diagnostic snapshot of the condition, enhancing quality imaging and early detection of the encephalic lesion. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42 :157–161, 2014