Baby Justin's body is very lean right now — only 3.5 percent of his body weight is fat.  This will change over the next few weeks as his body begins to store and use fat.

Justin's eyelids are still fused but he is now making blinking movements.  His spine is now hardened bone, and so are his ribs, humerus bones, and femur bones. 

His hands are strong now and can grip with force.