Cytomegalovirus (CMV) in pregnancy

Cytomegalovirus (CMV) is a common viral infection related to herpes. It typically causes no signs or symptoms in healthy children and adults — although some may experience a mononucleosis-like illness — and doesn't require treatment. But cytomegalovirus is of concern in pregnancy because the mother can pass the virus to her fetus, which increases the risk of birth defects.

Cytomegalovirus is the most common congenital (present at birth) infection. Most babies who are infected with cytomegalovirus before birth will show no signs or symptoms of CMV at birth. But according to the Centers for Disease Control and Prevention, up to 15 percent will develop neurological abnormalities, such as deafness, blindness or mental retardation.

A doctor can confirm a CMV infection in a pregnant woman by a blood test. If a pregnant woman has cytomegalovirus, a doctor can test the fetus for infection by amniocentesis. Ultrasound may detect abnormalities in the fetus.

Cytomegalovirus is treated with antiviral medications. But these drugs aren't proved to be safe in pregnancy. Also, there is no evidence that they protect the fetus. If you have cytomegalovirus, your doctor will want to closely monitor your pregnancy. If your baby shows signs and symptoms of cytomegalovirus at birth, treatment may include an antiviral medication.

To prevent CMV infection in pregnancy, wash your hands with soap and water before meals and especially after changing diapers. If you develop a mononucleosis-like illness in pregnancy, see your doctor.