###Human: Should we concern about the baby if the maternal serum is reactive for CMV? ###Assistant: Hi. I have gone through the attachment (attachment removed to protect patient identity). I can understand your concern. CMV (cytomegalovirus) IgG and IgM suggests that you have cytomegalovirus infection and it can spread to the baby. 90 % of infections are asymptomatic. But 5 to 15 % may have hearing loss, mental retardation, and microcephaly. These are the tests which should be done in the baby. They are spin enhanced culture and virus isolation in tissue culture. It is the most sensitive and specific test for diagnosis. Other tests such as urine, saliva, CMV antigen test, CT (computed tomography), MRI (magnetic resonance imaging), hearing test, ophthalmological evaluation, CBC (complete blood count), and LFT (liver function test) should also be done. The child should be examined soon by the neonatologist. Infection can spread by breastfeeding. Breastfeeding should be stopped until you show the child to the neonatologist.