"Your baby is no longer an embryo! Though he's barely the size of a kumquat -- just an inch or so long, crown to bottom -- and weighs less than a quarter of an ounce, he now has completed the most critical portion of his development. This is the beginning of the so-called fetal period, a time when the tissues and organs in his body rapidly grow and mature. His vital organs -- the liver, kidney, intestines, brain, and lungs -- are now in place and starting to function. His liver continues to make blood cells, and the yolk sac, which previously supplied these cells, is no longer needed and begins to disappear. During the next three weeks, your baby's length will more than double to nearly 3 inches. His head is proportionately smaller now than it was a few weeks ago, but it's still almost half the length of his entire body.
His forehead temporarily bulges with his developing brain and sits high on his head; it will later recede to give him a more human appearance. Each day, more minute details -- including tiny fingernails, toenails, and peach-fuzz hair -- start to appear on his body. His fingers are now completely separated; his arms bend at the elbow and curve slightly; his hands are flexed at the wrist and meet over his heart; his legs are lengthening; and his feet may be long enough to meet in front of his body. He is busily swallowing amniotic fluid and kicking his legs."