The evaluation of cardiac biometry in major cardiac defects detected in early pregnancy

The objective was to evaluate early cardiac biometry in fetuses with structural cardiac defects between 10 and 17 weeks of gestation using our normative data about fetal heart biometry. A retrospective case series, patients were selected from all cases with congenital heart disease diagnosed between 10 and 17 weeks of gestation in our prenatal unit between 1999 and 2000. A schematic sonographic examination, including nuchal translucency (NT) thickness measurements, was performed and was followed by fetal Doppler echocardiography. The transversal heart diameter, both ventricular dimensions, heart area, heart circumference, thoracic diameter, thoracic circumference, thoracic area, pulmonary trunk diameter and aortic diameter were measured and the cardiothoracic ratios were calculated. Doppler evaluation of the umbilical arteries, ductus venosus and umbilical vein was performed. Fetal karyotyping was obtained by amniocentesis or chorionic villous sampling. During the study period, 31 cases of congenital heart disease between 10 and 17 weeks of gestation were diagnosed. Of these, two fetuses presented with ectopia cordis and six with insufficient cardiac biometric measurements. In the remaining 23 fetuses, different complex abnormalities with a high rate of chromosomal abnormalities (91%) were present. Fetal heart biometry was normal in 22% and abnormal in 78%. NT thickness measurements were performed before 14 weeks of gestation and ten of 12 fetuses (83%) presented with an increased NT. Both fetuses with normal NT showed an abnormal fetal heart biometry. Venous Doppler evaluation was performed in 22 cases and 12 fetuses (55%) demonstrated an abnormal venous Doppler. There were ten fetuses (45%) with normal venous Doppler; in seven of these cases, fetal heart biometry was partly abnormal. This study shows the feasibility of first and early second trimesters' fetal echocardiography and the applicability of cardiac biometry in these instances. In this context, early fetal heart biometry and NT thickness measurements may be complementary methods for the prenatal diagnosis of some major congenital heart defects. In early pregnancy, some cardiac defects like tricuspid valve dysplasia, coarctation of the aorta, aortic stenosis, tetralogy of Fallot or pulmonary stenosis may already show similar changes in the relation of the diameters of the fetal heart and great arteries, as seen in the second trimester. Therefore, evaluating the different cardiac ratios may have a high diagnostic value in early pregnancy.     

The three-vessel and tracheal view of the fetal heart: an in utero sonographic evaluation

OBJECTIVES: To establish a nomogram for fetal cardiac three-vessel view diameter changes during gestation. METHODS: The study is a prospective cross-sectional evaluation of 338 male and female fetuses between 14 and 38 weeks of normal singleton pregnancies. Measurements of fetal pulmonary artery, aorta and superior vena cava diameters, performed on a transverse view of the upper mediastinum were conducted using transvaginal ultrasonography between 14 to 18 weeks and transabdominal after 19 weeks' gestation. RESULTS: Adequate measurements of the three cardiac vessels were obtained in 338 fetuses. The regression equations for vessel diameters modeled as function of gestational age were pulmonary artery diameter (mm) = -2.275 + 0.273 x gestational age (week), aorta diameter (mm) = -1.77 + 0.227 x gestational age (week), and SVC diameter (mm) = -0.98 + 0.142 x gestational age (week). The correlation coefficients between gestational age and the diameter of the vessels were, r = 0.93, r = 0.93 and r = 0.86 for pulmonary artery, aorta and SVC respectively (all found to be highly statistically significant, p < 0.0001). The normal mean and 90% prediction limits were defined. CONCLUSION: Our data present the normal range of fetal heart three-vessel diameters during gestation. They may allow intrauterine assessment of their development and an adjunct in the detection and evaluation of great vessel pathology.     

Early prenatal diagnosis of major cardiac anomalies in a high-risk population

OBJECTIVE: To examine the accuracy of early fetal echocardiography performed in a high-risk population combining transvaginal and transabdominal routes. METHODS: A series of 330 high-risk pregnancies were screened by transvaginal and transabdominal scan at 12-17 weeks' gestation in a prospective multicentre trial in Spain between September 1999 and May 2001. A total of 334 fetal heart examinations were performed, including four twin pregnancies. Maternal age ranged from 17 to 46 years (mean 33 years with 36% of women over 34 years). The median gestational age at scan was 14.2 weeks (range 12-17 weeks). For each fetus, visualization of the four-chamber view, the origin of the great arteries, aortic and ductal arches and systemic venous return was attempted in a segmental approach. B-mode and colour/pulsed Doppler flow imaging were used in all cases. The duration of complete heart examination was less than 30 minutes. The examinations were performed by three experienced operators. Reliability was assessed by conventional transabdominal echocardiography at 20-22 weeks, by postnatal follow-up in the first three months of life, and/or by autopsy in cases of termination of pregnancy. RESULTS: The rate of successful visualization of the fetal heart was 94.6% (316/334). In 48 out of 334 (14.4%) fetuses the final diagnosis was abnormal. In 38 out of 48 (79.2%) cases with heart defects the diagnosis was suspected at early echocardiography. In the group with congenital heart defects, 27 cases had an abnormal karyotype (56.3%) and 31 cases showed extracardiac anomalies (64.6%). There were 10 false-negative cases at early scan. There were no false-positive diagnoses. CONCLUSIONS: This experience stresses the usefulness of early fetal echocardiography when performed by expert operators on fetuses specifically at risk for cardiac disease. The high rate of successful visualization of the fetal heart provides a reliable diagnosis of major cardiac defects at this early stage of pregnancy.     

Transvaginal sonographic detection of embryonic-fetal abnormalities in early pregnancy

OBJECTIVE: To estimate the detection rate of abnormalities by transvaginal ultrasound in early pregnancy. METHODS: We prospectively analyzed records of 3592 sequential pregnant women at 10-16 weeks' (singleton) gestation (mean 13 weeks and 2 days). After exclusion of 114 women, there were 3478 women in the study. Each woman underwent a transvaginal sonographic survey for fetal anomalies as well as biometric measurements. Fetuses diagnosed with malformations were followed to delivery, and those without underwent transabdominal sonography at 18-24 weeks' gestation.Results: The anomaly detection rate by transvaginal ultrasound was 51.6% (33 of 64; 95% confidence interval [CI] 38.7, 64.2) in early pregnancy, and the detection rate by transvaginal ultrasound combined with second-trimester transabdominal ultrasound was 84.4% (54 of 64; 95% CI 73.1, 92.2). Cystic hygroma and fetal hydrops were the anomalies detected most frequently by transvaginal ultrasound. Low detection rates for abnormalities of the face and of the cardiac, skeletal, and urinary systems were found even when both methods were used. CONCLUSION: Transvaginal sonography appears to be an effective way to identify many congenital fetal anomalies in early pregnancy. There is a good probability of diagnosing cystic hygroma and fetal hydrops, although other abnormalities, particularly heart defects, are associated with lower detection rates.     

Fetal screening of congenital heart disease

Echocardiograms of two hundred and ninety normal fetuses at 18-39 weeks of gestation were studied with a real-time linear scanner (3.5 MHz). Aortic valvular diameter, pulmonary valvular diameter, mitral valvular diameter, tricuspid valvular diameter and total cardiac dimension were measured. These parameters increased with fetal growth. The ratios of pulmonary to aortic valvular diameter and of tricuspid to mitral valvular diameter were more than 1, suggesting right ventricular dominance in the fetal hearts. The cardio-thoracic ratio was about 50% in this period. The four-chamber view, left ventricular long-axis view, ventricular short-axis view, short-axis view of the great arteries, the view of the aortic arch and the view of the inferior and superior vena cava were also recorded. These six views could be obtained in 9.8% of all subjects at the same time. Detection rates for these views were the greatest in pregnancy at 22-33 (especially 28-29) weeks of gestation. The ventricular short-axis view and short-axis view of the great arteries were easily detected in the dorsoposterior position, whereas the view of the aortic arch was obtained in the dorsoanterior position. It was concluded that fetal echocardiography needed to be performed at least twice, at 22-23 and 28-29 weeks of gestation, and this would be useful in diagnosing some congenital heart diseases.     

Using ultrasonic measurement of cardiac size in predicting congenital heart defect.

A Duplex Color apparatus equipped with real-time imaging and Doppler sector scanner was used to scan fetal hearts, ranging from 17 to 41 weeks gestational age. A total of 323 normal fetuses were studied. The four-chamber view was obtained in a horizontal section just above the level of the fetal diaphragm. Five variables of the Chinese fetal heart in relation to the width of the right ventricle, width of the left ventricle, ratio of right ventricle/left ventricle (RV/LV), length of the fetal heart and the cardiac volume of a four-chamber view were set against gestational age in weeks and expressed in regression equations. The ratio of RV/LV is quite constant in relation to the gestational age. The mean ranges between 0.9916 for 17 weeks gestation and 1.0045 for a term fetus. In 10 abnormal cases with congenital cardiac defects, using the 5th and the 95th percentiles of this normal data as cutoff points, the RV/LV ratio had the highest sensitivity rate of 70% (7/10) in predicting fetal cardiac anomaly. The width of the left ventricle was the second most sensitive parameter with a sensitivity of 4/10 (40%). The RV/LV ratio of a four-chamber view is a simple, time-saving screening parameter for predicting congenital cardiac defects antenatally.     

Prenatal diagnosis of bilateral diaphragmatic hernia by fetal sonography

This report describes a case of prenatally diagnosed bilateral diaphragmatic hernia. At 22 weeks' gestation, ultrasound revealed a cystic structure behind the fetus's heart on the axial image at the level of the cardiac four-chamber view. This suggested a left-sided congenital diaphragmatic hernia with herniation of the stomach into the left hemithorax. However, the left-to-right midline shift of the heart was minimal, which is not typical of left-sided congenital diaphragmatic hernia. Throughout the 30th week of gestation, the right and left branches of the pulmonary artery were hypoplastic compared with the values in normal fetuses of the same gestational age. The presumptive diagnosis was bilateral congenital diaphragmatic hernia. A female newborn weighing 2900 g was delivered at 37 weeks' gestation, and she died at 7 h of age. An autopsy revealed large defects on both sides of the diaphragm. In conclusion, prenatal diagnosis of bilateral diaphragmatic hernia is possible with fetal sonography.     

Fetal cardiac asymmetry: a marker for congenital heart disease

Objective: To determine the sensitivity of prenatally detected fetal cardiac asymmetry as a sonographic marker for congenital heart disease.Methods: The normal ratios of pulmonary artery to aorta diameters and of right ventricle to left ventricle diameters were derived from normal fetuses scanned at 17 weeks or more in a 65-month period. Cross-sectional diameters of cardiac ventricles and great arteries were measured at the level of the valves at the time of the scan. Fetuses with confirmed cardiac anomalies detected prenatally during the study were examined to identify how many had cardiac asymmetry, determined by abnormal ratios.Results: Linear regression analysis of the group of 881 normal fetuses showed the normal pulmonary artery to aorta diameter ratio remained constant throughout pregnancy and the normal right ventricle to left ventricle ratio increased slightly with progressing gestational age. The 90% confidence intervals were 0.79, 1.24 for the right ventricle to left ventricle ratio and 0.84, 1.41 for the pulmonary artery to aorta ratio. Of the 73 fetuses with abnormal hearts, 66% had either ventricular or great artery asymmetry (at least one of the two ratios was abnormal). However, if no asymmetry was present, the cardiac defect was more likely to be a minor one.Conclusion: Cardiac asymmetry was present in two-thirds of fetuses with cardiac anomalies diagnosed prenatally. If cardiac asymmetry is found, a more thorough examination of the fetal heart is indicated.     

Accuracy and limitations of transabdominal fetal echocardiography at 12-15 weeks of gestation in a population at high risk for congenital heart disease

Objective Evaluation of transabdominal fetal echocardiography at 12–15 weeks of gestation.
Design Retrospective analysis.
Setting Tertiary fetal cardiology unit.
Sample Two hundred twenty-nine consecutive fetuses imaged at 12–15 weeks of gestation over a 45-month period.
Methods Retrospective analysis of echocardiography and autopsy reports.
Main outcome measures Accuracy of early echocardiography for the detection of abnormalities of the cardiac connections.
Results Diagnostic images were obtained in 226/229 fetuses (98.7%). Abnormalities of the cardiac connections were detected in 13 fetuses (5.7%) on the initial scan. Where information was available (   n = 11  ), the echocardiographic findings were confirmed at autopsy or postnatally. In two of the 13 cases of congenital heart disease, repeat echocardiography was necessary to provide additional cardiological information. Of the 213 cases in whom a normal initial report was issued, four (1.7%) had congenital heart disease diagnosed later in pregnancy (   n = 3  ) or postnatally (   n = 1  ). Three of these fetuses had haemodynamically insignificant ventricular septal defects and one developed a dilated cardiomyopathy later in gestation.
Conclusions Transabdominal fetal echocardiography can be performed at 12–15 weeks of gestation permitting accurate early detection of major congenital heart defects in a high risk population. Some forms of congenital heart disease, usually minor, may not be detectable at such an early stage.     

Nuchal translucency thickness and fetal cardiac flow velocity in normal fetuses at 11-13 weeks of gestation

OBJECTIVE: To investigate the relationship between nuchal translucency thickness and cardiac flow velocity in normal fetuses at 11-13 weeks of gestation. Subjects and METHODS: Eighteen normal pregnancies were prospectively studied with transvaginal sonography and pulsed and color Doppler ultrasound. Flow velocities at the fetal atrioventricular valves (mitral and tricuspid valve) and outflow tract levels (ascending aorta and pulmonary artery), and at the descending aorta were recorded. Nuchal translucency thickness was also measured. RESULTS: Mitral peak velocity during early diastolic filling correlated with gestational age. Mitral peak velocities during early diastolic filling and atrial contraction, tricuspid peak velocity during early diastolic filling, ascending aorta peak velocity, and pulmonary artery peak velocity correlated well with nuchal translucency thickness. There was an inverse correlation between umbilical artery pulsatility index and gestational age. CONCLUSIONS: These results suggest that the increase of nuchal translucency thickness in normal fetuses at 11-13 weeks of gestation may be the consequence of changes in fetal cardiac functions.     

Fetal echocardiography: accuracy and limitations in a population at high and low risk for heart defects.

OBJECTIVE: Our objective was to assess the accuracy of prenatal echocardiography in detecting congenital heart defects in patients at high and low risk for structural cardiac anomalies. STUDY DESIGN: Sixty-nine consecutive fetuses with congenital heart defects who had had prenatal ultrasonography at greater than or equal to 18 weeks' gestation were evaluated to determine the accuracy of prenatal ultrasonography in identifying structural cardiac defects. Thirty-nine patients were at high risk and 30 patients were at low risk for cardiac anomalies. All fetuses were scanned with standard four-chamber and outflow tract views. Data concerning extracardiac anomalies and karyotypic abnormalities were tabulated. The accuracy of the four-chamber view alone in identifying congenital heart defects was evaluated. RESULTS: Fifty-seven of 69 fetuses (83%) were prenatally identified ultrasonographically as having a heart defect. There was no difference in the sensitivity of detecting cardiac anomalies between high-risk and low-risk groups. When the four-chamber view was used, only 63% of fetuses were recognized as having an abnormal heart. Extracardiac anomalies were noted in 36% and karyotypic abnormalities in 17% of patients. CONCLUSION: The four-chamber and outflow tract views done routinely in an ultrasonography laboratory seeing a mixed population of patients was successful in detecting 83% of fetuses with structural cardiac malformations. Because 43% of the fetuses with heart defects were referred for low-risk indications, systematic ultrasonographic examination of the fetal heart should not be reserved only for those at high risk.     

First trimester ultrasonographic diagnosis of fetal structural abnormalities in a low risk population

Objectives Ultrasonographic screening between 12⁺⁰¹ and 13⁺⁶ weeks for fetal structural abnormalities using transab dominal sonography and, where necessary, transvaginal sonography in a low risk population.
Design A prospective observational study
Setting London teaching hospital
Methods Pregnant women with a total of 1632 low risk viable fetuses between 12⁺⁰ and 13⁺⁶ weeks of gestation were scanned using transabdominal and, where necessary, transvaginal sonography (40%). If the anatomical survey was normal, the women underwent routine 18-20 week anomaly scans. Pregnancy outcomes were obtained from radiological and neonatal computerised databases, and postal or telephone patient enquiry.
Results Seventeen (1.0%) major structural abnormalities were diagnosed in the study group. Of these, 11 (64.7%) were diagnosed at the 12-13 week scan, three diagnosed in the mid-trimester and three postnatally. Of the fetal abnormalities diagnosed antenatally, 78.6% were diagnosed in the first trimester. The sensitivity of abnormality detection by the combination of both first and second trimester scans was 82.3%. In addition, a significant number of missed abortions (   n = 36  ) were also diagnosed by the first trimester scan.
Conclusion This study has demonstrated the potential of screening a low risk population for fetal abnormalities at 12-13 weeks of gestation using transabdominal sonography and, where necessary, transvaginal sonography. Larger studies are required to establish the clinical value of the first trimester scan.     

Prenatal ultrasound diagnosis of congenital heart disease associated with intrauterine growth retardation. A report of 2 cases

Two fetuses with extreme growth retardation (IUGR) of 31 and 34 weeks gestation were studied using a combination of two dimensional echocardiography (2DE), pulse wave Doppler (PWD) and differential measurement of the instantaneous vessel diameter techniques. The first fetus was diagnosed as having univentricular heart or possible double outlet right ventricle (DORV). Descending aorta blood flow was reduced as was indexing for weight. The second fetus was diagnosed as having univentricular heart with periodic bigeminal and trigeminal rhythm. Descending aorta blood flow was measured on two occasions and was reduced both times. Indexing for weight was within normal limits the first time and showed gross reduction on the second occasion prior to fetal demise. Fetal death occurred in both cases at 34 weeks gestation. Cardiovascular evaluation in fetuses with IUGR is useful as the detection of severe congenital cardiac abnormalities may substantially alter the management of these pregnancies, in particular caesarean section may be avoided when the prognosis for the fetus is considered hopeless.     

妊娠10至17周胎儿四腔心的超声检测研究

目的 研究妊娠10至17周正常胎儿心脏四腔结构,为早期宫内诊断胎儿心脏异常提供帮助。方法 应用彩色多谱勒超声检测137例孕10至17周的正常胎儿心脏四腔结构。结果 ①孕10周可探测到44％胎儿心脏腔图孕13周以后均能探测到心脏四腔图;②左右心室的内径、心脏的横径、心脏面积、室间隔厚度与孕周呈高度正相关。③右左心室内径之比为1;④心胸比例随孕周轻度增加,此孕期心脏占据胸腔面积的1/5～1/4。而不是孕晚期的1/3。结论 孕13周至17周胎儿心脏的左右心室基本均匀发展,未呈现右心优势现象;心胸比例小于孕晚期;应用高分辨率的超声仪在此期可以探测到胎儿四腔心,有助于早期诊断胎儿心脏异常。     

Transvaginal fetal echocardiography in early pregnancy: normative data

Fifty-two transvaginal ultrasonographic examinations were performed between 10.0 and 14.9 weeks' gestation for the purpose of documenting normal fetal cardiac anatomy. All standard cardiac projections could be obtained by gestational week 12, and many were imaged by week 11. The four-chamber view was visualized in 90% of fetuses at 12 weeks' gestation and in 100% of fetuses examined at 13 weeks. The aortic root in short axis projection and the left ventricle in long axis view could be imaged in 70% and 40% of fetuses, respectively, by 12 weeks' gestation. Aortic and pulmonary valves were first visualized at 12 weeks, as were five-chamber, ductus arteriosus, and aortic arch views. The mitral and tricuspid valves were resolved in 60% of fetuses by 11 weeks' gestation. This study of normal cardiac anatomy suggests that there may be significant potential for the diagnosis of many fetal cardiac anomalies during the late first and early second trimesters of pregnancy.     

Real-time 3-D echocardiographic evaluation of the fetal heart using instantaneous volume-rendered display

AIM: Using new real-time 3-D fetal echocardiography with instantaneous volume-rendered display, we evaluated the heart anatomy of a number of normal fetuses during pregnancy. METHODS: Eighteen normal fetuses in 17 pregnancies (16 singletons and one twin) at 18-38 weeks' gestation were studied using a transabdominal real-time 3-D ultrasound machine. This machine proved capable of providing continuous 3-D sonographic images every 0.05 and 0.035 s without the need for an external workstation or other additional, costly equipment. For each patient, the fetal heart was first monitored using conventional 2-D echocardiography and was monitored again within 10 min using real-time 3-D echocardiography. RESULTS: Consecutive real-time 3-D images showing a four-chamber view, long-axis view, short-axis view, and right ventricular outflow tract view were obtained in 100%, 66.6%, 38.8%, and 22.2% of fetuses in the study, respectively. Morphological changes to each atrium or ventricle could be observed clearly and in detail throughout the cardiac cycle. The opening and closing of each valve were clearly visible. Moreover, these observations could be made from any direction. CONCLUSIONS: Real-time 3-D echocardiography provides a novel means for evaluation of the fetal heart in 3-D in real time in the second and third trimester of pregnancy. Real-time 3-D echocardiography may be an important modality in future fetal cardiac research and in evaluation of congenital heart disease in the fetus.     

Prenatal measurement of testicular diameter by ultrasonography: development of fetal male gender and evaluation of testicular descent

Prenatal ultrasonography has evolved through advancements in imaging technology and observer experience. The purpose of the present study was to evaluate fetal testicular descent and diameter in relation to gestational age. A prospective cross-sectional study on 331 fetuses from an unselected population underwent a detailed assessment of testicular descent and diameter at 20-40 weeks' gestation by means of transabdominal sonography (91.2%) and transvaginal sonography (8.8%) when necessary. Fetal gender was identified in the transverse and sagittal planes and maximum testicular diameter was measured. The mean testicular diameter (in millimeters) per week and the 95% confidence interval (CI) were defined. Testicular descent was not observed prior to 23 weeks' gestation, with 6.6% of the fetuses having one testis descended at 23 weeks and 98.2% after 32 weeks. A linear relationship between testicular diameter and gestational age was observed. The present results chart the time course for testicular descent and provide a centile chart for fetal testicular diameter from 25 to 40 weeks' gestation. These findings may aid prenatal diagnosis of associated abnormal conditions as well as investigations into the clinical finding of abnormal testicular size.     

Transvaginal assessment of fetal anatomy at 11 to 16 weeks of gestation in relation to fetal position

OBJECTIVE: To investigate the ability of the high-frequency transvaginal scanning technique to assess embryo-fetal anatomy in early pregnancy in relation to fetal position and in comparison with transabdominal scan. METHODS: A study population of 1,402 pregnant women were examined by transvaginal ultrasonography performed at 10(+1) to 16(+0) weeks of pregnancy. At 14(+1) to 16(+0) weeks of gestation, an ultrasonographic examination was performed in 247 pregnant women by transvaginal and transabdominal route. The criteria necessary for an adequate visualization of fetal organs and structures were met. RESULTS: The visualization rate of complete fetal anatomy increased with increase in menstrual age and fetal position affected this possibility. A detailed brain anatomy was more easily viewed with the fetus in the cephalic or transverse position than in the breech position, whereas the thoracic and abdominal anatomy were viewed more easily with the transverse position compared to the cephalic or breech position. Complete surveys of fetal anatomy were possible in 50% and 62% of women with transabdominal scan and in 85% and 85% with transvaginal one at 15 and 16 weeks' gestation, respectively (p < 0.001). CONCLUSION: A detailed assessment of fetal structures was possible in most cases at 13 weeks of gestation. Fetal position can influence this capability. At 14(+1) to 15(+0) weeks' gestation more anatomical surveys were completed with a transvaginal scan compared to a transabdominal one and this was influenced by fetal position.     

Color Doppler flow mapping of fetal heart

Color Doppler flow mapping of fetal heart was performed in 582 fetuses between 16 and 38 weeks of gestation. Congenital heart diseases were excluded in 522 fetuses correctly. In 59 fetuses structural and/or functional cardiac abnormalities were diagnosed. In one fetus small multiple ventricular septal defects were missed. The most important additional information obtained by color Doppler flow mapping was: (1) Diagnosis of insufficiencies of atrioventricular valves; (2) Demonstration of turbulent high velocity jet in stenosis of semilunar valve; (3) Reverse flow in ascending aorta in atresia of aortic valves and on ductus arteriosus and main pulmonary artery in atresia of pulmonary valves; (4) Reverse perfusion of ductus arteriosus and main pulmonary artery as well as an antegrade turbulent high velocity jet in severe pulmonary stenosis as part of tetralogy of Fallot; (5) Bidirectional interventricular shunting of blood in ventricular septal defect. Color Doppler flow mapping allows rapid screening for flow abnormalities of the fetal heart. Exact localisation of sample volume by pulsed wave Doppler in area of abnormal flow pattern is possible, thus significantly reducing the Doppler examination time. The accuracy of prenatal diagnosis of congenital heart diseases is improved by application of color Doppler flow mapping, in particular in presence of complex cardiac defects.     

Two-dimensional echocardiographic assessment of normal fetal cardiac anatomy

The fetal heart is visualized routinely during the antepartum ultrasound examination. Because of the advent of high-resolution, real-time ultrasound instruments, details of fetal cardiac anatomy can now be defined. Fifty consecutive fetuses were examined in utero to assess the ability of two-dimensional echocardiography to define intracardiac anatomy at various gestational ages. A complete examination required at least three standard echocardiographic views of the heart: four-chamber, short-axis and long-axis views. In 30 of the 50 fetuses studied (60%) only one examination was necessary to obtain this information. Ten patients had a second examination later in gestation that complemented the findings of their first study. In all but two fetuses, detection of all four cardiac chambers and at least one semilunar valve was possible. Mitral-semilunar valve continuity was detected in all. The quality of echocardiographic imaging was enhanced by the fetal occiput posterior position (three views obtained in 83% of the fetuses studied). Breech position did not affect imaging quality. Prior to 30 weeks of gestation, fetal movement hampered analysis of fetal cardiac anatomy in some patients.