Fetal echocardiography

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Fetal echocardiography
Purposediagnose cardiac conditions in the fetal stage

Fetal echocardiography, or Fetal echocardiogram, is the name of the test used to diagnose cardiac conditions in the fetal stage. Cardiac defects are amongst the most common birth defects. Their diagnosis is important in the fetal stage as it might help provide an opportunity to plan and manage the baby as and when the baby is born. Not all pregnancies need to undergo fetal echo.

Patient criteria

Specific maternal and fetal conditions would indicate the need for this test. these conditions are as listed below:

Maternal:

Fetal:

Fetal Echo is usually performed by a Pediatric Cardiologist but may also be performed by a Sonologist. [1]

To date, no detrimental effects in humans have been demonstrated.

The performance of a fetal echocardiogram requires experience and a systematic approach. Guidelines for training have been formulated, and only qualified individuals should perform this highly specialized examination. A brief description of the examination is presented here for interest only. The first step is to determine the position and orientation of the fetus within the uterus. Within the thorax, the heart, because of its motion, is usually the easiest and most recognizable structure to examine.

The four-chamber view is most important and should be recorded first. For orientation, the left atrium is identified by the presence of the septum primum and the pulmonary veins. Cardiac situs can be determined by identifying the systemic veins and the position of the atria relative to the liver and spleen. Next, the atrioventricular valves are identified, with the tricuspid valve slightly more apical than the mitral valve. The outlet portions of the heart are then evaluated. Cardiac measurements can be made and compared with normal values that have been defined for all gestational ages.

Doppler techniques can be used to visualize blood flow through the heart, great vessels, and umbilical vessels. Assessment of fetal arrhythmias is best accomplished by using a combination of M-mode and Doppler recordings. When these arrhythmias are present, a careful search for structural heart disease is mandatory. With this approach, a wealth of diagnostic information is available. Knowledge of complex congenital heart disease before delivery allows therapeutic interventions to begin immediately after birth and can be life saving for such patients. In both of these examples, knowledge about the presence and severity of congenital cardiac defects facilitated management of labor and delivery and allowed perinatal care to be optimized.

The critical role of echocardiography in prenatal diagnosis is evident, and both the accuracy and safety of the test are now well established. The structures in these images are small, however, and random movements of the fetus make for a challenging and time-consuming examination. Despite these factors, fetal echocardiography has provided clinicians with earlier diagnosis of heart disease and a better understanding of fetal hemodynamics.

Today, a dedicated fetal echocardiogram can detect nearly 100% of serious congenital heart disease. Yet most pregnant women do not have a fetal echocardiogram but rather undergo a general obstetric ultrasound that may detect only around a third of fetal heart disease. To improve detection, some propose universal fetal echocardiography. [2] But others cite cost and lack of specialized personnel as barriers that prevent echocardiography for every fetus. [3]

Fetal Echocardiogram is done in select patients. The best way to improve pickup in majority if the patients is by training sonologists to perform a more thorough evaluation. It has been traditionally taught that a four chamber visualisation is enough but current experiences suggest that may not be enough. A better evaluation would include a 4 chamber, a 5 chamber and a 3 vessel evaluation(3).

Related Research Articles

<span class="mw-page-title-main">Amniocentesis</span> Sampling of amniotic fluid done mainly to detect fetal chromosomal abnormalities

Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is necessary to conclusively diagnose the majority of genetic disorders, with amniocentesis being the gold-standard procedure after 15 weeks' gestation.

<span class="mw-page-title-main">Echocardiography</span> Medical imaging technique of the heart

Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an echocardiogram, a cardiac echo, or simply an echo.

<span class="mw-page-title-main">Obstetric ultrasonography</span> Use of medical ultrasonography in pregnancy

Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus.

<span class="mw-page-title-main">Prenatal testing</span> Testing for diseases or conditions in a fetus

Prenatal testing is a tool that can be used to detect some of these abnormalities at various stages prior to birth. Prenatal testing consists of prenatal screening and prenatal diagnosis, which are aspects of prenatal care that focus on detecting problems with the pregnancy as early as possible. These may be anatomic and physiologic problems with the health of the zygote, embryo, or fetus, either before gestation even starts or as early in gestation as practicable. Screening can detect problems such as neural tube defects, chromosome abnormalities, and gene mutations that would lead to genetic disorders and birth defects, such as spina bifida, cleft palate, Down syndrome, Tay–Sachs disease, sickle cell anemia, thalassemia, cystic fibrosis, muscular dystrophy, and fragile X syndrome. Some tests are designed to discover problems which primarily affect the health of the mother, such as PAPP-A to detect pre-eclampsia or glucose tolerance tests to diagnose gestational diabetes. Screening can also detect anatomical defects such as hydrocephalus, anencephaly, heart defects, and amniotic band syndrome.

<span class="mw-page-title-main">Polyhydramnios</span> Excess of amniotic fluid in the amniotic sac

Polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in about 1% of pregnancies. It is typically diagnosed when the amniotic fluid index (AFI) is greater than 24 cm. There are two clinical varieties of polyhydramnios: chronic polyhydramnios where excess amniotic fluid accumulates gradually, and acute polyhydramnios where excess amniotic fluid collects rapidly.

<span class="mw-page-title-main">Hydrops fetalis</span> Human disease of fetuses

Hydrops fetalis or hydrops foetalis is a condition in the fetus characterized by an accumulation of fluid, or edema, in at least two fetal compartments. By comparison, hydrops allantois or hydrops amnion is an accumulation of excessive fluid in the allantoic or amniotic space, respectively.

A transthoracic echocardiogram (TTE) is the most common type of echocardiogram, which is a still or moving image of the internal parts of the heart using ultrasound. In this case, the probe is placed on the chest or abdomen of the subject to get various views of the heart. It is used as a non-invasive assessment of the overall health of the heart, including a patient's heart valves and degree of heart muscle contraction. The images are displayed on a monitor for real-time viewing and then recorded.

<span class="mw-page-title-main">Pulmonary atresia</span> Medical condition

Pulmonary atresia is a congenital malformation of the pulmonary valve in which the valve orifice fails to develop. The valve is completely closed thereby obstructing the outflow of blood from the heart to the lungs. The pulmonary valve is located on the right side of the heart between the right ventricle and pulmonary artery. In a normal functioning heart, the opening to the pulmonary valve has three flaps that open and close.

<span class="mw-page-title-main">Atrioventricular septal defect</span> Medical condition

Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" or "endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the heart that creates connections between all four of its chambers. It is a very specific combination of 3 defects:

<span class="mw-page-title-main">Fetal surgery</span> Growing branch of maternal-fetal medicine

Fetal surgery also known as antenatal surgery, prenatal surgery, is a growing branch of maternal-fetal medicine that covers any of a broad range of surgical techniques that are used to treat congenital abnormalities in fetuses who are still in the pregnant uterus. There are three main types: open fetal surgery, which involves completely opening the uterus to operate on the fetus; minimally invasive fetoscopic surgery, which uses small incisions and is guided by fetoscopy and sonography; and percutaneous fetal therapy, which involves placing a catheter under continuous ultrasound guidance.

<span class="mw-page-title-main">Simpson–Golabi–Behmel syndrome</span> Congenital disorder

Simpson–Golabi–Behmel syndrome (SGBS), is a rare inherited congenital disorder that can cause craniofacial, skeletal, vascular, cardiac, and renal abnormalities. There is a high prevalence of cancer associated in those with sgbs which includes wilms tumors, neuroblastoma, tumors of the adrenal gland, liver, lungs and abdominal organs. The syndrome is inherited in an X-linked recessive manner. Females that possess one copy of the mutation are considered to be carriers of the syndrome but may still express varying degrees of the phenotype, suffering mild to severe malady. Males experience a higher likelihood of fetal death.

<span class="mw-page-title-main">Persistent left superior vena cava</span> Medical condition

In anatomy, a persistent left superior vena cava is the most common variation of the thoracic venous system. It is present in between 0.3% and 0.5% of the population, and is an embryologic remnant that results from a failure to involute.

<span class="mw-page-title-main">Nuchal scan</span> Routine ultrasound done between 11 and 14 weeks pregnancy

A nuchal scan or nuchal translucency (NT) scan/procedure is a sonographic prenatal screening scan (ultrasound) to detect chromosomal abnormalities in a fetus, though altered extracellular matrix composition and limited lymphatic drainage can also be detected.

<span class="mw-page-title-main">Maternal–fetal medicine</span> Branch of medicine

Maternal–fetal medicine (MFM), also known as perinatology, is a branch of medicine that focuses on managing health concerns of the mother and fetus prior to, during, and shortly after pregnancy.

<span class="mw-page-title-main">Percutaneous umbilical cord blood sampling</span>

Percutaneous umbilical cord blood sampling (PUBS), also called cordocentesis, fetal blood sampling, or umbilical vein sampling is a diagnostic genetic test that examines blood from the fetal umbilical cord to detect fetal abnormalities. Fetal and maternal blood supply are typically connected in utero with one vein and two arteries to the fetus. The umbilical vein is responsible for delivering oxygen rich blood to the fetus from the mother; the umbilical arteries are responsible for removing oxygen poor blood from the fetus. This allows for the fetus’ tissues to properly perfuse. PUBS provides a means of rapid chromosome analysis and is useful when information cannot be obtained through amniocentesis, chorionic villus sampling, or ultrasound ; this test carries a significant risk of complication and is typically reserved for pregnancies determined to be at high risk for genetic defect. It has been used with mothers with immune thrombocytopenic purpura.

<span class="mw-page-title-main">Velamentous cord insertion</span> Velamentous placenta

Velamentous cord insertion is a complication of pregnancy where the umbilical cord is inserted in the fetal membranes. It is a major cause of antepartum hemorrhage that leads to loss of fetal blood and associated with high perinatal mortality. In normal pregnancies, the umbilical cord inserts into the middle of the placental mass and is completely encased by the amniotic sac. The vessels are hence normally protected by Wharton's jelly, which prevents rupture during pregnancy and labor. In velamentous cord insertion, the vessels of the umbilical cord are improperly inserted in the chorioamniotic membrane, and hence the vessels traverse between the amnion and the chorion towards the placenta. Without Wharton's jelly protecting the vessels, the exposed vessels are susceptible to compression and rupture.

<span class="mw-page-title-main">Single umbilical artery</span> Medical condition

Occasionally, there is a single umbilical artery (SUA) present in the umbilical cord, as opposed to the usual two. This is sometimes also called a two-vessel umbilical cord, or two-vessel cord. Approximately, this affects between 1 in 100 and 1 in 500 pregnancies, making it the most common umbilical abnormality. Its cause is not known.

<span class="mw-page-title-main">Right-sided aortic arch</span> Medical condition

Right-sided aortic arch is a rare anatomical variant in which the aortic arch is on the right side rather than on the left. During normal embryonic development, the aortic arch is formed by the left fourth aortic arch and the left dorsal aorta. In people with a right-sided aortic arch, instead the right dorsal aorta persists and the distal left aorta disappears.

Isolated levocardia is a rare type of organs' situs inversus in which the heart is still in normal position but other abdominal viscera are transposed. Isolated levocardia may occur with heart defects and patients without having operations have low life expectancy: only about 5% to 13% of patients survive more than 5 years. Therefore, even though the risk of cardiac surgeries is high, once patients are diagnosed, operations are suggested to be held as soon as possible. Isolated levocardia is congenital. So far, there is not sufficient evidence to prove that chromosome abnormalities will result in isolated levocardia, and the cause of isolated levocardia is still unknown.

Beryl Rice Benacerraf was an American radiologist and professor of obstetrics, gynecology and reproductive biology and radiology at Harvard Medical School. She was a pioneer in the use of prenatal ultrasound to diagnose fetal abnormalities, including Down syndrome. In 2021, she was recognized as a "Giant in Obstetrics and Gynecology" by the American Journal of Obstetrics & Gynecology.

References

  1. Tasha, Ilir; Brook, Rachel; Frasure, Heidi; Lazebnik, Noam (2014). "Prenatal detection of cardiac anomalies in fetuses with single umbilical artery: diagnostic accuracy comparison of maternal-fetal-medicine and pediatric cardiologist". Journal of Pregnancy. 2014: 265421. doi: 10.1155/2014/265421 . ISSN   2090-2735. PMC   3955584 . PMID   24719766.
  2. Acherman, RJ; Evans, WN; Luna, CF; Rollins, R; Kip, KT; Collazos, JC; Restrepo, H; Adasheck, J; Iriye, BK (2007). "Prenatal detection of congenital heart disease in southern Nevada: the need for universal fetal cardiac evaluation". Journal of Ultrasound in Medicine. 26 (12): 1715–9, quiz 1720–1. doi:10.7863/jum.2007.26.12.1715. PMID   18029923. S2CID   23418117.
  3. Bahtiyar, MO; Copel, JA (2007). "Improving detection of fetal cardiac anomalies: a fetal echocardiogram for every fetus?". Journal of Ultrasound in Medicine. 26 (12): 1639–41. doi:10.7863/jum.2007.26.12.1639. PMID   18029914. S2CID   42147891.