About Fetal Heart Ultrasound Objectively speaking, as a non-invasive diagnostic imaging technique, the accuracy of ultrasound is difficult to achieve 100%. In addition, the accuracy of ultrasound diagnosis is very much influenced by the experience of the examining physician, especially for cardiac ultrasound and fetal cardiac ultrasound. Therefore, if a fetal heart problem or suspicion is found during a major screening ultrasound during pregnancy, go to a specialized hospital for a specialized fetal heart ultrasound by an experienced ultrasonographer who is familiar with congenital heart disease if possible. A comprehensive and accurate fetal echocardiogram report is an important basis for clinicians to predict the condition and develop a treatment plan. The following are some of the common problems of fetal heart ultrasound. 1. Perpetual left superior vena cava Perpetual left superior vena cava refers to the venous blood flow from the left side of the head and neck and left upper extremity, which alone returns directly to the right atrium via the left superior vena cava. This is a normal anatomic variant that has no effect on the circulation and does not require disposition. However, the permanent left superior vena cava is relatively more likely to occur with other congenital heart defects. Therefore, it is best to have a specialized fetal heart ultrasound to look closely at the heart structure and to exclude other cardiac anomalies. In the majority of cases, the bright spots are the echoes of normal structures of the heart such as the leaflet tendons and papillary muscles, which may be due to the small size of the child’s heart and the difficulty of clearly identifying these structures on ultrasound. In rare cases, the bright spots are ventricular tumors, which need to be dynamically observed for changes in size and number of tumors. The size of the foramen ovale as observed by ultrasound during pregnancy is not considered to be an accurate predictor of atrial septal defect after birth. However, according to the current medical technology, atrial septal defect is a simple congenital heart disease that can be completely cured by interventional or surgical procedures, and the success rate of treatment can reach 99% or higher. 4. Small foramen ovale and distorted ductus arteriosus Keeping the foramen ovale and ductus arteriosus open and blood flowing during pregnancy is essential to maintain normal fetal circulation. If the foramen ovale is closed, or becomes too small to pass blood flow effectively, the fetal blood flow circulation will be abnormal, such as edema, accelerated or slowed heart rate, etc. Therefore, if everything is in good condition in the fetus, it is likely that the ultrasound measurement is off. Distortion of the arterial duct does not affect blood flow through and is of little clinical significance. However, as a precautionary measure, the fetal heart should be observed and the heart ultrasound should be repeated if necessary. 5. Right aortic arch For simple right aortic arch with no other malformation in the heart, the majority of children will have no problem in the future. Only a small number of children with combined left ductus arteriosus or vagal left subclavian artery may have difficulty swallowing, breathing difficulties, recurrent respiratory infections and other symptoms due to compression of the trachea and esophagus after birth. Those with obvious symptoms need surgical treatment. 6.Aortic arch narrowing Overall, it is difficult to accurately diagnose the presence and degree of aortic arch narrowing by ultrasound during pregnancy because of the fetal cardiovascular anatomy and circulatory characteristics, the fetal heart is undergoing rapid growth and developmental changes, and the limitation of the mother’s ultrasound window. For those who are suspected of having aortic arch abnormalities during pregnancy, cardiac ultrasound should be performed as soon as possible after the birth of the child, and cardiac CT should be performed to assist in the diagnosis if necessary to facilitate the development of a treatment plan. Children with severe aortic constriction or interrupted aortic arch require monitoring and treatment as soon as they are born, so confirmation of the diagnosis is crucial. 7. tricuspid regurgitation First ultrasound should be performed to observe the tricuspid valve structure for abnormalities if possible. If the tricuspid valve structure is normal, a small amount of regurgitation has no effect on the heart and does not need to be disposed of. Conditions may allow the ultrasound to be repeated in a few weeks to observe any changes in regurgitation flow. If the tricuspid valve is abnormal, or if it is combined with a moderate amount of regurgitation or more, ultrasound should be repeated periodically to monitor the regurgitation dynamically. A large amount of tricuspid regurgitation may affect fetal heart function and requires special attention for regular follow-up. Ultrasound should be repeated as soon as possible after the birth of the child to clarify the diagnosis. Some children with severe disease may require monitoring and treatment from birth.