Fetal echocardiography is a special ultrasound technique that allows examining the morphological and functional features of the fetal heart during pregnancy. Allows even before birth, noninvasively detect congenital heart pathology. It is usually performed at 18-24 weeks of gestation. Fetal EchoCG makes it possible to assess the condition of the heart cavities, atrial septa of heart valves, and main vessels. It is used for prenatal diagnosis of congenital heart defects and cardiac arrhythmias in the fetus, which makes it possible to optimally plan further tactics of their treatment.
EchoCG is prescribed at a high risk of developing cardiac pathology in the fetus. This risk may be indicated by the presence of CHD in parents or next of kin, cases of birth in the family of children with congenital heart disease, the detection of chromosomal abnormalities in the fetus (for example, Down syndrome, Patau syndrome). Factors that can increase the likelihood of heart defects in the fetus are intrauterine infections (rubella, toxoplasmosis, cytomegaly, etc.); taking antibiotics, antiepileptic drugs during pregnancy; the presence of endocrine and systemic diseases in the mother (diabetes mellitus, SLE, rheumatoid arthritis); drug and alcohol use; the age of the pregnant woman is over 38 years old.
Additional fetal echocardiography is indicated in cases when screening ultrasound revealed a delay in fetal development, little or polyhydramnios, fetal dropsy, cardiac arrhythmias (tachycardia, bradycardia, arrhythmias), cardiomegaly or abnormalities of the structure of the heart, multiple malformations of internal organs.
With the help of echocardiography in the prenatal period, such CHD as:
- hypoplasia of the left heart can be identified
- pulmonary artery atresia
- Ebstein anomaly
- tetrad of fallot
- three – atrial heart
- transposition of the main vessels
- aortic coarctation
- abnormal drainage of pulmonary veins and many others.
Their prenatal diagnostics allows specialists (obstetrician-gynecologist, neonatologist, cardiac surgeon) to competently plan the tactics of pregnancy management, choose the best method of delivery, carry out the necessary preoperative preparation of the newborn and cardiac surgery in the optimal time. The reliability of EchoCG in detecting congenital anomalies of the structure and functioning of the heart is 90%. Nevertheless, immediately after birth, in order to confirm the diagnosis, an ultrasound of the child’s heart is mandatory.
Types of research
When performing EchoCG, various scanning modes are used to visualize the fetal heart in detail:
- Two-dimensional echocardiography is used to assess the anatomy of the main structures of the heart (chambers, valves, main arteries and veins). The image is displayed as a two-dimensional slice.
- M-echocardiography – allows you to observe intracardial structures (walls of the chambers of the heart, valve flaps) in motion mode, assess the systolic function of the ventricles.
- Doppler echocardiography is used to study hemodynamics in the vessels and chambers of the heart, as well as to assess the heart rate. It is carried out in the mode of CDM and pulse Dopplerography.
Methodology of conducting
The most reliable results can be obtained at 18-24 weeks of pregnancy. Transabdominal access is used in the study, however, if necessary, at a gestation period of less than 18 weeks, EchoCG can be performed transvaginally. The procedure lasts about 30-40 minutes and, according to the procedure, resembles a conventional ultrasound. During the fetal echocardiography procedure, the pregnant woman should be calm and relaxed; perhaps, on the recommendation of a doctor, she will have to stop taking certain medications a few days before the planned study.
The standard echographic examination includes an assessment of the four-chamber section of the heart (the position of the heart in the thoracic cavity, the structure of the ventricles and atria, the formation of the interventricular and atrial septa, movements of the mitral and tricuspid valves), the main arteries (the relative position and diameter of the aorta and pulmonary trunk), characteristics of cardiac activity (heart rate, rhythmicity of atrioventricular contractions). The protocol of fetal echocardiography must be familiarized with the obstetrician-gynecologist observing pregnancy, who will comment on the diagnostic results to the woman, explain all the risks.
The quality of ultrasound imaging depends on the level of qualification and experience of the specialist, the type of equipment used, the gestation period, the position of the fetus, little or much water, the thickness of the subcutaneous fat layer on the anterior abdominal wall of the pregnant woman.
Fetal echocardiography allows a detailed study of the anatomy and functioning of the fetal heart using high-frequency ultrasound waves. Evaluation of fetal cardiac activity can be carried out by auscultation, phonocardiography, cardiotocography. Echocardiography is not a mandatory ultrasound during pregnancy and is prescribed only in cases where other studies give reason to suspect the presence of CHD or severe rhythm disturbances in the child.
If cardiac defects incompatible with life are detected in the fetus, it is recommended to terminate the pregnancy. In cases where congenital heart defects are subject to surgical correction, the operation can be performed shortly after birth. Fetal echocardiography, as a method of prenatal diagnosis, is indispensable for developing a strategy for managing pregnancy, childbirth and the early neonatal period.