Cytomegalovirus is a member of the herpes virus family and is the most likely type of virus to be transmitted to an infant during pregnancy. According to the American Academy of Pediatrics, about 1 percent of babies delivered with this type of infection are born with congenital cytomegalovirus infection. Most babies with congenital cytomegalovirus infection are born unwell, but some are found to have serious pathology at birth that will cause a range of long-term problems that are difficult to resolve. Other babies may not show any signs of illness at first, but months or even years later may be found to have hearing loss or other complications. Can it be transmitted to my baby? It depends on when you were first infected. At least 50% of women develop antibodies to cytomegalovirus before they become pregnant, meaning they have been infected before. Like other herpes viruses, cytomegalovirus infection initially remains dormant in the body, but can be reactivated in the body, especially if your immune system is not strong enough, leading to what is called recurrent cytomegalovirus infection. However, the chances of transmitting the virus to your baby during a recurrent infection are very low, and the risk of acquiring serious complications is even lower. In case of a first cytomegalovirus infection, it is recommended to wait at least 6 months before considering pregnancy, so that the baby is at less risk of developing cytomegalovirus infection. However, if you are infected for the first time during pregnancy, the chances of passing the virus to your baby are much higher. About 1-4% of women who are not previously infected will be at risk of contracting cytomegalovirus during their first pregnancy, and about 30%-50% of these women in turn will have babies who are likely to develop intrauterine infections, with a higher risk of serious health problems remaining after the baby is born. Can a baby’s health be affected by a virus infection? About 85-90% of congenital cytomegalovirus infections in newborns are “latent”, meaning they are born asymptomatic, and the vast majority of these babies remain healthy and do not develop cytomegalovirus-related complications, but most of these babies (about 5-15%) have problems, if any, with hearing loss. In addition, 10-15% of newborns infected with cytomegalovirus in utero are born with severe congenital complications such as central nervous system malformations, growth restriction, microcephaly, splenomegaly and hepatomegaly, jaundice, and rashes due to subcutaneous hemorrhage, and some fetuses may die prematurely as a result. Up to 90% of survivors may have long-term illnesses such as hearing impairment, visual defects, mental retardation, or other neurological disorders. What are the circumstances of cytomegalovirus infection? Cytomegalovirus is transmitted through direct contact with the bodily fluids of an infected person, such as saliva, urine, feces, semen, vaginal secretions, blood, tears, and breast milk. What kinds of situations can be infected? For example, sharing utensils, kissing, or having sexual relations with an infected person. You can also get infected if you touch the bodily fluids of an infected person and then touch your mouth or nose. How is the virus transmitted from mother to baby? During pregnancy, the virus can be transmitted to the baby through the placenta. There is also a risk of infection when you come in contact with secretions from an infected cytomegalovirus or blood at delivery, and when you suck on the breast milk of an infected mother after birth. However, most infants show few or no symptoms even when infected at birth or from breastfeeding (especially full-term infants). Therefore, infected pregnant women can still choose vaginal delivery or breastfeeding. How is the infection confirmed? The diagnosis cannot be confirmed without rigorous testing. Most people do not know if they have ever been infected with cytomegalovirus or if they are currently infected with the virus, and unless their immune system is too weak, they usually do not show any symptoms. There are only symptoms similar to those of mononucleosis, such as fever, swollen glands, sore throat, and fatigue. We can test for cytomegalovirus with a blood test, but many pregnant women do not actually have this test done. What should I do if I am diagnosed? If the blood test confirms that you have cytomegalovirus, a full ultrasound scan is recommended to look for cytomegalovirus-related fetal growth or placental abnormalities. It is also possible that your doctor may perform an amniocentesis to see if your baby is infected with cytomegalovirus, but this test will not accurately determine whether your baby will have any future health problems as a result.