Case report

This is a case of the heterotaxy syndrome (left isomerism) associated with a cephalocele diagnosed at 25-week of pregnancy in a woman with non-contributive history. Our ultrasound revealed several abnormalities of the fetus. The fetal head presented a large occipital defect and encephalocele. The enlarged heart, with pericardial effusion, was oriented to the left (levocardia), but there was a large atrioventricular septal defect present. The inferior vena cava connection to the heart was not seen and at the level of the four-chamber view of the heart there were two vessels running behind the heart, representing the descending aorta and dilated azygos vein, because of the collateral venous return via the azygos vein due to the inferior vena cava interruption. The aortic arch was right-sided. The stomach was located on the right side and so was the gallbladder.

The parents opted for the termination of the pregnancy, but refused further postnatal studies of the fetus.

Images 1, 2: The image 1 show transverse fetal scans at the level of the four-chamber view of the heart (left part of the image) and at the level of the stomach (the right part of the image). The heart is enlarged and oriented to the left; the stomach is located on the right side. The image 2 shows the four chamber view of the heart with the atrioventricular septal defect. Note the atrial septum is not present and both the atrial appendages have a left auricular configuration.

Images 3, 4: The image 3 shows the right sided stomach and gallbladder. The image 4 shows the large atrioventricular septal defect of the heart during diastole.

Images 5, 6: The image 5 shows the large atrioventricular septal defect of the heart during systole. The image 6 shows color Doppler scan at the level of the 3-vessel view of the heart. The superior vena cava appears enlarged, because it gathers the collateral blood flow of from the inferior vena cava reaching the superior vena cava via the azygos vein.

Images 7: The image 7 shows a color Doppler transverse scan of the fetal thorax at the level of the four-chamber view. The blood flow can be seen entering the ventricles via the comon atrioventricular valve.  

Images 8, 9: The images show transverse scans at the fetus at the level of the four-chamber view of the heart (image 8) and at the level of the stomach (image 9). Note the two vessels (arrows) running side by side near the spine, representing the aorta and azygos vein continuation.

Images 10, 11: The images show parallel course of the aorta and vena azygos vein.

Images 12, 13: The image 12 shows 3D sagittal scan of the fetal head and spine with the encephalocele. The image 13 shows transverse scan of the fetal head with the large occipital defect and encephalocele.