22 weeks

He now looks like a miniature newborn, checking in at 10.9 inches and almost 1 pound. His skin will continue to appear wrinkled until he gains enough weight to fill it out, and the fine hair (lanugo) that covers his head and body is now visible. His lips are becoming more distinct, and the first signs of teeth are appearing as buds beneath his gum line. His eyes are developed, though the iris (the colored part of the eye) still lacks pigment. Eyelids and eyebrows are in place, and his pancreas, essential for hormone production, is developing steadily.

Babies develops two kinds of hair in utero--the soft, downy body hair called lanugo, which generally falls off before or shortly after birth, and the hair on his head. Many parents are surprised (to say the least) to see their baby's hair at birth--blond couples often have black-haired offspring, dark ones are just as likely to deliver a little blond or redhead, and parents who have tight, wiry curls often produce babies with soft, loose ones. The bottom line seems to be that birth hair--or lack thereof--bears little resemblance to the child's "real" hair. The birth hair generally falls out by the time the baby is 6 months old, to be replaced by a more logical head of hair.

Near the end of this month, several changes take place in the baby's skin. It becomes covered with a fatty yellowish substance called vernix, which protects its skin from the constant exposure to amniotic fluid. Under the skin, particularly around the neck and back, a special tissue called brown fat is forming. Until it disappears a few weeks after birth, brown fat produces heat, which the baby needs after leaving the warmth of the womb.