Anencephaly as a 1st congenital anomaly in fetal sonography

It is First congenital anomaly identified in utero with ultrasound. The diagnosis can be made as early as the 12th week of gestation and is typically made at the time of an attempted biparietal diameter determination for fetal age.

Imaging Findings :

Inability to identify normal brain tissue cephalad to the bony orbits or brainstem along with symmetric absence of the bony calvarium.

Anencephaly. Long-axis image of a 14-week fetus demonstrates a poorly developed, small head (arrows) visualized in continuity with the fetal spine (arrowhead).