During the fourth month, your baby's length will grow from 3 1/2 to 6 inches,
with weight quadrupling from one to four ounces. Lanugo is forming all
over your baby's skin. This is a fine hair that will fall off just prior
to delivery.
The toes and fingers of your baby are becoming fully formed. The
spleen, bone marrow and liver are developing. Amazingly, your baby may be
able to suck his or her thumb. The heart of your baby is beating between
110 and 160 times per minute.
Mom, you may feel your hands and feet are always warm. This is due to
the relaxation of your arteries and veins, which enables maximum cardiac output
without raising your blood pressure.