Baby Bolin: 6 weeks

How Baby Bolin is growing:

The cells that will make up all of his/her body parts and systems are dividing furiously as his/her body begins to take shape. Right now Baby Bolin about the size of a small lentil bean (4 to 5 millimeters across).

His/ her eyes and nostrils are beginning to take shape. Shallow pits on the sides of his/her head mark developing ears, and arms and legs appear as protruding buds. His/Her hands and feet look like paddles, with thick webbing between the developing digits, but the fingers and toes will soon become more distinct.

Below the opening that will later be your baby's mouth, there are small folds where his/her neck and lower jaw will eventually develop. (Inside, his/her tongue and vocal cords are just beginning to form.)

Baby Bolin's heart (which is starting to divide into the right and left chambers) is beating about 100 to 130 beats per minute — almost twice as fast as yours — and blood is beginning to circulate through his/her body.

His/Her intestines are developing and tiny breathing passages are beginning to appear where her lungs will be. Muscle fibers are also starting to build and, halfway through this week, he or she will likely start moving their tiny limbs!