Carnegie Stage 21 Definition

Age is approximately 52 postovulatory days

Length is approximately 22-24mm

External Features Include: the hands are slightly flexed at the wrists and nearly come together over the cardiac eminence; the feet are also approaching each other and the toes of the two sides sometimes touch; the superficial vascular plexus of the head has spread upward to form a line at somewhat more than half the distance from eye-ear level to the vertex.

(O'Rahilly R and Muller F [1987] Developmental Stages in Human Embryos. Carnegie Institute, Washington, Publication no. 637)