Most doctors don't test for herpes (even during a standard STD test) unless you ask them to. A blood test to determine if you are infected with the herpes virus, called a serology, is more accurate than the basic swab method. If you are considering pregnancy and do not know if you or your partner have been exposed to the herpes virus, it is especially important to find out if either of you is infected. That's because there is a chance that the active herpes virus can be passed to an infant during its trip through the birth canal. In some cases, your doctor may choose a cesarean section delivery to ensure that your baby is not infected. You may wonder why these precautions are necessary, since, while annoying and embarrassing, the herpes virus does not cause bodily harm beyond blisters. While this is true for you, newborn babies do not have the developed immune system that is needed to fight herpes simplex and may die if they contract the virus.