16 Weeks, 3 Days

Baby at 16 weeks.

At 4 1/2 inches long (head to bottom) and 3 1/2 ounces, the baby is about the size of an avocado. In the next three weeks, he'll go through a tremendous growth spurt, though, doubling his weight and adding inches to his length. The arms continue to develop. The bending of fingers and the clenching of the fists is now possible. His lower limbs are much more developed now. His head is more erect than it has been, and his eyes have moved toward the front of his head. The baby's ears are close to their final position, too. Some of his more advanced body systems are working, including his circulatory system and urinary tract. His heart is now pumping about 25 quarts of blood each day, circulating his total blood volume through his body many times. (By the end of the pregnancy, this will increase to about 190 quarts.) The patterning of his scalp has begun, though his hair isn't recognizable yet. Although closed, his eyes are moving (slowly), and he's even started growing toenails.

We may go in to K's office tomorrow to check on the gender again, just to be sure.