Introduction
Congenital heart defects (CHD) introduce a serious public health concern that may occur in the heart during the prenatal development of a fetus. The Centers for Disease Control and Prevention (2017) states that about 1% (40,000) of children are born with such defects in the United States annually, and 25% of these children have a critical condition. Babies with CHDs may look absolutely normal, but become critically ill or even die in a short period. Therefore, the detection of heart defects by such a method as fetal echocardiography is important. The purpose of this paper is to investigate the worth and accuracy of fetal echocardiography for congenital cardiac defects in a fetus using the studies published during the last five years.
Fetal echocardiography is a diagnostic technique that was introduced by Winsberg in 1972 (Liu, He, Li, & Zhang, 2014). This test is usually performed at 12-16 gestational age to screen for heart malformations. Its significance cannot be neglected because it may define a future intervention therapy, including surgery, prenatal care management, and postnatal improvements. Not all pregnant women are in need of fetal echocardiography. As a rule, it is enough to use a basic ultrasound for heart investigation. However, fetal echocardiography is recommended for mothers who have heart disease or other medical conditions that may influence the work of the heart, use drugs, alcohol, or medications that affect the heart or have a similar family history.
In this paper, prenatal diagnosis of fetal congenital cardiac abnormalities with the help of fetal echocardiography has been shown to have a significant impact on prenatal and postnatal management and outcomes on babies.
Congenital Cardiac Defects
Fetal echocardiography is a necessary tool in prenatal screening and diagnosis because it helps to define what kind of cardiac defect a fetus and explain what kind of problems a future baby may have. There are several main congenital cardiac defects that may be defined after mothers are diagnosed with the help of fetal echocardiography: hypoplastic left and right heart syndrome, L-TGA and D-TGA, truncus arteriosus, and interrupted aortic arch.
Hypoplastic Left & Right Heart Syndrome
Hypoplastic left and right heart syndromes are severe congenital cardiac malformations that affect a normal blood flow in the fetus heart when blood supply depends on patency of the arterial duct (Clausen, 2015). Hypoplastic right heart syndrome (HRHS) is a rare condition among neonates that occurs when the right side structure of the heart remains to be undeveloped and influences the work of the heart chambers, valves, and blood vessels, and the amount of oxygen pumped from the heart to the lungs (Mohan, Mohan, Shukla, & Sethi, 2016). A pulmonary valve atresia is not formed, and tricuspid valve, as well as right ventricle and the pulmonary artery, are of a small size leading to numerous problems of pumping blood. Fetal echocardiography is used to define the sizes of valves.
Hypoplastic left heart syndrome includes changes and defects of the left side of the heart. During the prenatal development, this side of the heart can be formed in a wrong way, and certain malformations are observed. For example, the left ventricle is too small and nonviable, and mitral or aortic valves are not formed and have to be replaced (Rychik, 2014). The result of such malformations is the inability of this side of the heart to pump blood through the body and the necessity of the right side of the heart to work twice harder. The causes of this syndrome are still unknown, and the only solution that can be given in a heart transplant.
L-TGA and D-TGA
Transposition of the great arteries is a serious and one of the most common congenital cardiac defects that may be diagnosed by fetal echocardiography. It is a reversal of arteries which take responsibility for blood circulation in the heart (Unolt et al., 2013). There are two types of this condition: l-TGA (levo-transposition of the great arteries) and d-TGA (dextro-transposition of the great arteries). L-TGA is less dangerous for babies than d-TGA because of the reversal of two main arteries when the body is still able to receive oxygen-rich blood. The work of the arteries and their functions predetermine the way of how blood is circulated in the body. As soon as one tiny change occurs in a circulation process, there is a threat of having the shortage of oxygen in the blood and serious complications which lead to death. Fetal echocardiography can be used to detect this defect prenatally and observe the position of the aorta and the pulmonary artery in order to get prepared for corrective surgery right after a child is born.
Truncus Arteriosus
In the list of rare heart defects, truncus arteriosus takes one of the leading places because it is characterized by a single blood vessel coming out of the heart instead of a usual pair of vessels (Kumar, Devi, & Ghosh, 2017). It also leads to the creation of a hole between the lower chambers of the heart. Due to such complications, the blood that is rich in oxygen and the blood that lacks oxygen are mixed up and circulated in the body causing new problems. A fetal echocardiogram can show the structure of the heart and the work of each vessel in it. If one vessel leading from the heart and a hole between the ventricles are observed, truncus arteriosus may be diagnosed.
Interrupted Aortic Arch
Interrupted aortic arch (IAA) is a serious heart defect with a portion of the aortic arch being absent or discontinued. It is a rare genetic disorder that is usually associated with other heart defects and divided into three main types in regards to the results obtained from fetal echocardiography (Zhang et al., 2016). The location of the interruption defines the type of IAA: the first type (A) includes the malformations beyond the left subclavian artery, the second type (B) comprises the interruptions between the left carotid artery and the left subclavian artery, and the third type (C) introduces the interruptions which occur between the innominate artery and the left carotid artery (Park, 2014). An echocardiogram can be used to identify the type of interruption and give a proper diagnosis.
Associated Syndromes
Congenital heart diseases are usually accompanied by certain genetic syndromes and complications which show cardiac abnormalities. Ko (2016) suggests paying attention to such associated syndromes as Down syndrome, Williams syndrome, Turner syndrome, Noonan syndrome, and 22a11.1 deletion syndrome also known as DiGeorge syndrome. To succeed in diagnosing and treating congenital heart disease, clinicians have to understand the genetic etiology of every patient and learn the peculiarity of every anomaly and its genetic background.
Genetic causes of heart problems among neonates continue increasing today, and clinicians have to work hard to comprehend how to combine different symptoms and factors and come to the same conclusion (Fahed, Gelb, Seidman, & Seidman, 2013). Down syndrome is the abnormality caused by the presence of a third copy chromosome 21 that leads to certain intellectual disabilities, joint laxity, and cardiac defects (Ko, 2016). A disorder that is based on a microdeletion of chromosome 7q11.23 is known as Williams syndrome (Ko, 2016). Children with such syndrome usually have aortic stenosis and other cardiac malformations. Turner syndrome is observed among live born girls with specific cardiovascular malformations. This syndrome is caused by the absence of the second X chromosome that leads to a short stature and affected organ systems. Noonan syndrome is characterized by various phenotypes, including mild developmental delay, webbed neck, and lymphatic dysplasia. This syndrome may be detected by electrocardiogram or echocardiogram at the initial evaluation of a fetus. People with DiGeorge syndrome, or 22a11.1 deletion, differ from others due to a long face, downturned mouth, high nasal bridge, and small teeth. The combination of this syndrome with congenital heart defects turns out to be one of the leading causes among neonates. Therefore, early detection of these problems can save human lives.
Prenatal Care after Diagnosis
A fetal echocardiogram is one of the most reliable methods for giving prenatal diagnoses and make prenatal improvements possible. In many cases, congenital heart defects are treated by means of congenital heart surgeries. However, if there is a change to diagnose such defects prior to birth, successful coordination of delivery and prenatal counseling can help many families (Quartermain et al., 2015). In the United States, this type of assessment is not as frequently used as in other countries. Still, the US government and health associations take numerous steps to change this situation and provide future mothers with all necessary equipment and material to use the benefits of prenatal diagnosis. In the period from 12 till 16 gestational weeks, fetal echocardiography can be used to screen for fetal heart defects (Hutchinson et al., 2017). Some families agree to take this test and be the fetus screened for abnormalities. Some families reject this idea in order to stay as unaware about possible challenges as possible.
On the one hand, prenatal care and diagnosis may help parents and the medical staff get prepared for a special condition, choose fetal surgery if possible, and facilitate the process of fetus development. On the other hand, there are the situations when nothing can be done to help the fetus, and parents have to live with a thought that their baby can be born and die in a short period. It is the solution for parents to use or avoid prenatal care and diagnosis.
Postnatal Care and Management
Children with congenital heart defects have to be treated properly. Care and management play an important role because it may be long-term with the necessity to monitor the condition of a baby and short-term when one surgery is enough to solve a heart problem. In addition to surgery, babies with heart defects may use a heart transplantation option. Still, it is not always available to all patients, it is expensive, and wait time may be incompatible with a child’s condition (Hutchinson et al., 2017). Doctors also suggest neonate patients taking medications (inhibitors or beta blockers) that can facilitate the work of the heart, decrease the cases of depression, and control the level of blood.
Postnatal management should also include the discussion of the restrictions which cannot be neglected by children with congenital heart defects and their parents. As a rule, such children cannot run or climb trees, should avoid spicy food and physical exercises, and think about calm hobbies and spheres of interest. Finally, clinicians have to inform their patients about an increased risk of infections and their possible impact on the heart. Sometimes, one infection may cause serious damage to the heart that cannot be repaired. Parents should take responsibility for their sick children and make sure they offer enough comfort under different conditions.
Advantages and Disadvantages of Fetal Echocardiography
Taking into consideration the offered material about the existing congenital heart defects, their outcomes, and associated syndromes, some people start doubting about the importance of fetal echocardiography. A fetal echocardiogram is used to create a picture of the fetus heart and provide parents and clinicians with a chance to learn if a future child may be exposed to some heart defects. The positive aspects of fetal echocardiography include awareness of and confidence in the presence/absence of heart defects in a fetus, a possibility to improve the condition with the help of fetal surgery, and the provision of time to be prepared for delivery and care management, including correctional surgery or other interruptive steps. As soon as a cardiologist has enough information, it is possible to provide the family with information and counseling regarding the specific health condition of the fetus, identify the anticipated prognosis, and think about the most appropriate management steps. Fetal cardiac surgery may play a crucial role in fetal medicine and the lives of millions of American families. If there is a chance to identify a heart problem in the fetus, there is also a chance to find effective treatment and reduce the number of risks associated with the problem.
However, there are also several disadvantages of fetal echocardiography that people have to be aware of. For example, not all people want to know if their future children may have heart defects. Still, the presence of such possibility makes them think about what they can use to improve the life of their future babies and what they should never do. Numerous ethical and emotional problems can be raised around the necessity of fetal echocardiography. Besides, the results of fetal echocardiography are not always correct. Not a single doctor takes responsibility that no heart problems can be observed in children as soon as they are born. The only conclusion that can be made is that at the moment, no abnormalities are observed.
Conclusion
In general, the future of fetal echocardiography is safe. This diagnostic method may help millions of children to improve their health conditions, even if they have congenital heart defects and prepare their families for special conditions. In the United States, not all families are aware of the effects and urgency of fetal echocardiography. Therefore, it is necessary to think about the methods which can be used to educate people about fetal echocardiography and make them decide confidently. Prenatal diagnosis of fetal congenital cardiac anomalies plays an important role in pre- and post-natal management and care offered to babies. Still, it should be an individual decision of every woman whether to use fetal echocardiography for screening for heart defects or stay unaware till delivery hoping that everything can be good for her and her baby.
References
Centers for Disease Control and Prevention. (2017). Congenital heart defects. Web.
Clausen, H. (2015). Hypoplastic left heart syndrome. Paediatrics and Child Health, 25(1), 18-22.
Fahed, A.C., Gelb, B.D., Seidman, J.G., & Seidman, C.E. (2013). Genetics of congenital heart disease: The glass half empty. Circulation Research, 112(12). Web.
Hutchinson, D., McBrien, A., Howley, L., Yamamoto, Y., Sekar, P., … Hornberger, L.K. (2017). First-trimester fetal echocardiography: Identification of cardiac structures for screening from 6 to 12 weeks’ gestational age. Journal of the American Society of Echocardiography, 30(8), 763-772.
Kumar, P., Devi, A., & Ghosh, G. (2017). An infant with truncus arteriosus with situs inversus with single atrium: A case report. Journal of Cardiology Cases, 15(3), 107-109.
Liu, L., He, Y., Li, Z., & Zhang, L. (2014). Application of two-dimensional echocardiography combined with enhanced flow in diagnosing fetal heart malformation. Clinical and Experimental Obstetrics & Gynecology, 41(2), 195-201.
Mohan, J.C., Mohan, V., Shukla, M., & Sethi, A. (2016). Hypoplastic right heart syndrome, absent pulmonary valve, and non-compacted left ventricle in an adult. Indian Heart Journal, 68(2), 229-232.
Park, M.K. (2014). Pediatric cardiology for practitioners (6th ed.). Philadelphia, PA: Elsevier Health Sciences.
Quartermain, M.D., Pasquali, S.K., Hill, K.D., Goldberg, D.J., Huhta, J.C., Jacobs, J.P., … Ungerleider, R.M. (2015). Variation in prenatal diagnosis of congenital heart disease in infants. Pediatrics, 136(2), 378-285.
Rychik, J. (2014). Hypoplastic left heart syndrome. Circulation, 130, 629-631.
Unolt, M., Putotto, C., Silvestri, L.M., Marino, D., Scarabotti, A., Massaccesi, V., … Marino, B. (2013). Transposition of great arteries: New insights into the pathogenesis. Frontiers in Pediatrics, 1(11). Web.
Zhang, D., Zhang, Y., Ren, W., Sun, F., Guo, Y., Sun, W., … Cai, A. (2016). Prenatal diagnosis of fetal interrupted aortic arch type a by two-dimensional echocardiography and four-dimensional echocardiography with b-flow imaging and spatiotemporal image correlation. Echocardiography: A Journal of Cardiovascular Ultrasound and Allied Techniques, 33(1), 90-98.