How does anencephaly affect brain development?

Anencephaly is a severe cephalic disorder characterized by the absence of significant portions of the brain and skull.

This condition occurs during early embryonic development—specifically within the first month of pregnancy—due to a failure of the upper region of the neural tube to close properly. Because the neural tube is the primitive structure from which the central nervous system develops, this failure prevents the normal formation of major brain structures.1

The condition is immediately apparent at birth, and because the brain development is fundamentally incomplete, infants born with anencephaly die at or soon after birth. Insufficient maternal intake of folic acid is considered a significant risk factor for this and other neural tube defects.1