This is not a good time to test your partner's sense of humor. A woman who has always been quick to laugh at herself will surprise you with a wailing retreat from the room if you dare mention the fact that she seems to be growing a mustache.
Hair goes through two stages: growth and rest. During pregnancy, the majority of your hair is in the growth stage, giving you a fuller head of hair. Two to four months after delivery, your hair moves into a resting stage that causes a noticeable increase in hair loss.
Even your hair won't escape the effects of the reproductive hormones that increase blood circulation and metabolism. By the fourth month you'll probably notice that your hair is growing faster and looks thicker and healthier than before. Or you might be one of the few whose hair becomes thinner, oilier, or drier. Either way, there will be noticeable changes in your hair.
Some women see drastic changes when their light hair turns darker, curly hair falls flat, or pencil straight hair turns curly. Most often the change is temporary, occurring during the pregnancy only. But many women claim their hair texture or color changes forever.
The hair on your head is not the only hair on your body that grows longer and gets thicker during pregnancy. Increased amounts of facial hair (particularly on the lips, chin, and cheeks) are the most obvious. But you might also see thicker hair on your arms, legs, back, and belly. Even the area covered by your pubic hair might expand. Much of this growth disappears within six months after the baby is born.
If your body hair is dark, you might find this unexpected feature of your pregnancy a bit embarrassing. Plucking and shaving are options, but avoid depilatories or bleaching cream. It's possible that they might be absorbed into the bloodstream and circulate into your womb.