This fetus presented with a thick nuchal translucency (6 mm) (1.4 MB video). The examination of the heart (1.8 MB video) appears to demonstrate the great vessels side-by-side (such as in transposition of the great arteries), and an apparent large atrioventricular septal defect. Note that the heart is only 4-5 mm. A chorionic villus sampling was performed which revealed a trisomy 18. Because of the size of the fetus, no autopsy could be performed and the cardiac diagnoses are only speculative. Several articles have suggested that cardiac anomalies were the cause of some thick nuchal translucencies^[1],^[2],^[3],^[4],^[5],^[6],^[7],^[8],^[9],^[10],^[11].

The spine of the fetus is on the left of the image. Note the large nuchal lucency. Great vessels side-by-side suggesting a transposition of the great arteries (not autopsy proven). White dots on the side of the image are 10 mm apart.

In these images the fetus has turned and the back is towards the bottom of the image, the left of the fetus is on the right of the images. The apex is at 12-1 o'clock. Note the small size of the heart, white dots on the side of the image are 10 mm apart. The black and white images fail to demonstrate the normal atrioventricular valves and the septum. The color frames demonstrate what appears to be absence of the portion of the interventricular septum close to the crux of the heart. These findings are consistent with an atrioventricular septal defect (not autopsy proven).

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