Clinical features, management, and outcome of children with fetal and postnatal diagnoses of isomerism syndromes.

BACKGROUND: Isomerism is associated with a complex spectrum of anomalies. There is paucity of data on prenatally detected cases. METHODS AND RESULTS: Between January 1990 and February 2004, 83 of 166 cases (50%) had a prenatal diagnosis of left isomerism (LAI; 52 of 97) or right isomerism (RAI; 31 of 69) at our institution. The spectrum of anomalies, management, and outcomes was compared for fetal and postnatal diagnoses of LAI and RAI. RAI more often than LAI was associated with AV septal defect (90% versus 56%; P<0.0001), pulmonary outflow obstruction (91% versus 37%; P<0.0001), total anomalous pulmonary venous drainage (73% versus 13%; P<0.0001), and abnormal VA connections (68% versus 33%; P<0.0001), whereas inferior vena cava interruption (3% versus 93%; P<0.0001), complete AV block (0% versus 13%; P=0.004), aortic obstruction (6% versus 33%; P<0.0001), and extracardiac defects (5% versus 25%; P=0.006) were less common. The spectrum of lesions was comparable for fetal and postnatal cases, except for AV block (fetal, 25%; postnatal, 0%; P=0.0002) and AV septal defect (fetal, 67%; postnatal, 42%; P=0.023) in LAI. Fetal demise was due mainly to pregnancy termination (LAI, 42%; RAI, 45%). Survival of actively managed children with LAI was significantly better than for those with RAI (P<0.0001) but did not differ with regard to fetal versus postnatal diagnosis. Most LAI cases required no intervention or underwent successful biventricular cardiac surgery (65%), unlike RAI cases (13%; P<0.0001). CONCLUSIONS: Prenatal diagnosis did not affect overall survival despite facilitated care. The prognosis of RAI was worse compared with LAI because of more complex associated cardiac defects and the inability to perform successful surgical procedures.

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.