Fetale Heterotaxie-Syndrome

The spectrum of conditions associated with heterotaxy syndromes includes a wide variety of cardiovascular and visceral anomalies that are differently distributed amongst the two clinical variants, left and right isomerism, and which determine the intrauterine as well as the postnatal course and outcome. An exact prenatal diagnosis is therefore warranted. Important sonographic markers in heterotaxy syndromes are the associated anomalies of the situs and cardiac defects. Prenatal differentiation of the two clinical variants can be based on the anomalies, the course of the inferior vena cava and the presence of a heart block.In left isomerism, mortality is highest in the prenatal period due to frequent association with a complete heart block and subsequent intrauterine heart failure. In the postnatal period, the outcome depends mainly on the associated cardiac malformations and their ability to be corrected.In contrast, in right isomerism the mortality is highest in the postnatal period. This is mainly due to the more complex type of associated cardiac malformations.