TABLE I.
Laterality Defects Inclusion Criteria, National Birth Defects Prevention Study, 1998–2007
| I. Situs inversus totalis |
| II. Heterotaxy: Requires at least three of the following features, selected from group 1–8 |
| 1. Characteristic congenital heart defectsa |
| Pulmonary venous anomalies |
| Totally anomalous pulmonary venous connection or drainage |
| Partially anomalous pulmonary venous connection or drainage |
| Atrial anomalies |
| Atrial situsambiguous or inversus |
| Common atrium |
| Common atrioventricularcanal(or septal) defects |
| Complete atrioventricularcanal defect |
| Partial atrioventricular canal defect |
| Transitional atrioventricular canal defect |
| Ventricular abnormalities |
| Hypoplastic or single left ventricleb |
| Hypoplastic or single right ventricle |
| Ventricular malposition (e.g., L-loop, superior-inferior, criss-cross) |
| Ventriculo arterial alignment abnormalities |
| Double-outlet ventricle |
| D-loop transposition of great arteries |
| L-loop transposition of great arteries |
| Truncusarteriosus |
| TOF (including TOF/PS, TOF/PA, and TOF/APV) |
| Ventricular outflow abnormalities |
| Subvalvar/valvar pulmonary stenosis |
| Pulmonary atresia with intact ventricular septum |
| Pulmonary atresia with ventricular septal defect (not TOF-type) |
| Valvar or subvalvar aortic stenosis |
| Coarctation of the aorta |
| 2. Biliary atresia |
| 3. Abdominal situs abnormality |
| Abdominal situs inversus |
| Situs ambiguous (midline or transverse liver, midline aorta, ipsilateral aorta, and IVC) |
| 4. Spleen abnormality (confirmed by imaging, autopsy, or by Howell-Jolly bodies) |
| Asplenia |
| Polysplenia |
| Single right-sided spleen |
| 5. Isomerism of bronchi |
| Bilateral left bronchial morphology |
| Bilateral right bronchial morphology |
| 6. Isomerism of the lungs |
| Bilateral two lobes (left-sidedness) |
| Bilateral three lobes (right-sidedness) |
| 7. Similar morphology of the atrial appendages (“isomerism”) |
| 8. Two of the following |
| Systemic venous anomalies |
| Bilateral superior vena cava |
| Interrupted inferior vena cava |
| Unroofed (absent) coronary sinus |
| Intestinal malrotation |
| Malrotation, nonrotation colon |
| Malrotation, small intestine |
| Absent gallbladder |
APV, absent pulmonary valve; CHD, congenital heart defect; PA, pulmonary atresia; PS, pulmonary stenosis; TOF, tetralogy of Fallot.
a
Adapted from Foerster et al. [2008, Table II].
b
Hypoplastic left ventricle or single right ventricle, and hypoplastic right ventricle or single left ventricle were coded with specific CHD codes such as tricuspid atresia or hypoplastic left heart syndrome.