Cytomegalovirus (CMV) is a virus that can be transmitted to a developing fetus before birth. CMV is a member of the herpes family of viruses that also includes chickenpox and mono. Primary CMV infection occurs in people who have never been exposed to the CMV virus before. Once a person becomes infected with CMV, the virus remains alive but dormant inside that person’s body for the rest of their lives. Recurrent CMV infection, is when a dormant virus become active again. This can occur if a person’s immune system becomes weakened, such as in the elderly or in people who have AIDS. CMV infection is usually harmless and rarely causes illness. However, for those who are pregnant, primary CMV infection can cause more serious problems than recurrent CMV infection. Most women who are infected with CMV, whether pregnant or not, will not develop any symptoms of the infection. Those that do experience symptoms may see fever, swollen glands, or lethargy.