Spectrum of cardiovascular disease, accuracy of diagnosis, and outcome in fetal heterotaxy syndrome.

Because there is a paucity of information regarding the diagnosis and outcomes of fetal heterotaxy syndrome (HS), this study sought to determine the spectrum of cardiac pathology, accuracy of diagnosis, and outcome of fetal HS. All cases of fetal HS encountered in the investigators' institution over a 10-year period through 2002 were identified. Prenatal and postnatal echocardiograms and medical records were reviewed. Seventy-one fetuses were diagnosed with HS, including 48 with left atrial isomerism (LAI) and 23 with right atrial isomerism (RAI). For LAI and RAI, most intracardiac lesions, the pulmonary venous connections, and superior vena caval anatomy were correctly diagnosed in utero (93%, 86%, and 77% accuracy, respectively), whereas hepatic venous connections and inferior vena caval-atrial connections in RAI were difficult to define (65% and 56% accuracy, respectively). Of 32 continued and followed pregnancies with LAI, 22 are currently alive at 48 +/- 30 months. Heart block and associated major extracardiac pathology were significantly more common in nonsurvivors with fetal LAI (p = 0.007 and 0.024, respectively). Outcomes were even worse for prenatally diagnosed RAI: of 14 continued pregnancies, only 3 are currently alive. In conclusion, fetal HS is associated with a broad spectrum of cardiac pathology, which can be diagnosed accurately in utero. Fetal LAI is associated with a mortality of 31%, with heart block and extracardiac pathology as primary risk factors for perinatal mortality. The outcome of prenatally diagnosed RAI is poor.