Congenital cytomegalovirus (CMV) is the most common virus that most people haven't heard of.
Most every one will catch CMV at some time in their life and never know they have it.
If a woman gets CMV for the first time while she is pregnant, she can be in a potentially dangerous situation. CMV infects almost 1 out of every 100 newborns in the country and is the most common congenital infection.