Fetal echocardiography: what it is, what it is for, and when it is performed
Fetal echocardiography is an examination to study the fetal heart during pregnancy: it is performed in the second trimester, between 19 and 22 weeks, to identify :
- The normal anatomy and function of the heart
- the presence of congenital heart disease
- The presence of cardiac hemodynamic effects due to other fetal or placental pathologies
It is not a routine examination, but may be required when there is suspicion of congenital heart disease of the fetus.
The most effective results are obtained between the 20th and 22nd weeks of gestation: the examination can also be brought forward to the 16th week in strong suspicion of heart disease; the examination can be repeated if necessary up to the 40th week.
- Fetal echocardiography is necessary when there are cardiac risks to the fetus, such as:
- Familiarity with congenital heart disease;
- Hereditary diseases that increase the risk of cardiac malformations;
- diabetic mother;
- Mother with autoimmune diseases;
- mother with phenylketonuria
- nuchal translucency increased in the first 3 months of pregnancy;
- accumulation of fluid in the subcutaneous tissues and serous cavities of the fetus (fetal hydrops);
- Growth delays during the second trimester of pregnancy;
- Monochorionic twin pregnancy (both fetuses share the same placenta);
- Problems highlighted byamniocentesis or villocentesis;
- Arrhythmias in the fetal heartbeat.
How to perform
Fetal echocardiography involves the use of an ultrasound probe that is not harmful to the fetus and is slid over the mother's abdomen.
Several projections are performed to properly visualize theanatomy of the heart and afferent structures.
By means of color Doppler, finally, blood circulation is studied:
- in the heart;
- In the large vessels;
- the heart rhythm
- The arteriovenous activity of the umbilical cord.
The examination is simple and absolutely painless, lasting between 30 and 40 minutes;
The examination time may be lengthened in the presence of
- Unfavorable fetal position
- Maternal acoustic impedance
- Twins
- Early or late gestational age
It is advisable to bring the results of any previous examinations with you.Fetal echocardiography also requires no preparation.
Fetal echocardiography proves to be particularly useful because it can identify most congenital heart disease, with an accuracy rate of 80-90%.
Limitations of the procedure
Fetal echocardiography although safe, has limitations in visualizationin some circumstances, such as:
- Obesity of the mother;
- Reduced amount of amniotic fluid(oligohydramnios) or increased(polydramnios);
- examinationeffected early or late;
- twin pregnancies;
- Excessive fetal movementsand/or inappropriate position.