These growths, commonly called skin tags, are normal. They usually pop up in places where clothing rubs against your skin, like under the arms and beneath your bra and underwear. "During pregnancy, increased estrogen levels stimulate overgrowth of normal skin," explains dermatologist David E. Bank, M.D. "Skin tags are completely harmless and often disappear after pregnancy." If they don't, your doctor can perform a simple laser procedure to remove them. You can't do much to treat them while you're expecting, however.