C'mon...

From CNN.com:

In the standard method of harvesting stem cells, researchers wait five days or so after fertilization until the embryo has become a ball of up to 150 cells. They obtain stem cells from the interior of the ball, which destroys the embryo.

I don't know if I would consider 150 cells a baby. That's compared to the total number of cells in the human body [which] is estimated to be between 75 and 100 trillion .