Our baby gets a new skill this week: he/she can now move his/her thumb in opposition to the fingers.  Our baby's also practicing the motion of breathing as the air sacs of the lungs develop more this week. 

The large intestine actually rotates 180 degrees counterclockwise and creates a square around the small intestine, framing it like a picture.  The corners of the colon attach to the body wall and end in an anal canal.  The small intestine is suspended in the abdomen at this point.

And this week, the baby's spleen will remove old red blood cells and produce antibodies.

Interestingly, at week 12, a baby's arms are proportional to its body, but the legs still have some growing to do. 

Our baby is approximately 3x as big as it was at the end of month 2, but about 50x as heavy!