ad. 12. What does tricuspid regurgitation (=insufficiency=TR) mean?
Tricuspid insufficiency is a functional abnormality. This defect allows the blood to flow backwards, from the right ventricle to right atrium through the atrioventricular valve, also called the tricuspid valve. It may be due to an anatomical anomaly, although it is most often a symptom of an overload of the right ventricle. An isolated tricuspid insufficiency of a minor degree is a variation of the norm, which disappears after some time. It often occurs after and during an increased activity of a fetus. According to our records, it appears even in 6.4% of healthy fetuses examined in the first trimester, however, when it comes to the genetic syndromes, it occurs in 42.9% of fetuses with the Down syndrome, in 63.6% with the Edwards syndrome and in 50% with the Patau syndrome, usually in combination with other characteristics. A substantial tricuspid insufficiency might increase the risk of genetic syndromes. Therefore, only an experienced sonologist, holding a certificate in detecting tricuspid insufficiency (the list of examiners can be found on the FMF website) is able to decide whether the insufficiency might be identified as a genetic marker because a lot of insufficiencies are trivial and should not be included into the patient’s risk. It is worth to analyze all ultrasound and biochemical parameters. It allows to optimize the further course of pregnancy and select only those patients, who need to undergo a more detailed examination, i.e. chorionic villus sampling or amniocentesis. If a specialist does not diagnose additional, suspicious symptoms, such as an increased speed of the flow through a pulmonary artery or an increased NT, a patient might stop worrying.
An isolated insufficiency disappears in almost 100% of cases and it is not observed in the second trimester. We tell our patients that “the baby grew out of the tricuspid insufficiency”.
It is worth to verify the flow through a pulmonary artery and the ductus arteriosus to make sure there are no characteristics of a right ventricular overloading.