Human cytomegalovirus (HCMV), which causes human disease, is very common in the population, and the prevalence of congenital CMV infection in China is 0.5%-1.12%. In severe cases, it can lead to a systemic infection syndrome called cytomegalic inclusion disease (CID).
Intrauterine infection with HCMV is the most common of the congenital viral infections and is classified as primary or recurrent. Primary refers to infection of the fetus during pregnancy. Recurrent refers to infection of the infant in the presence of IgG antibodies. The incidence of vertical transmission of primary infection in pregnancy to the fetus is about 40%, and women with the presence of antibodies to cytomegalovirus before pregnancy are at only 0.15%-1.10% risk of congenital infection.HCMV infection, on the one hand, significantly reduces cellular phagocytolysis, antigen presentation, and secretion of antiviral cytokines and regulatory factors; on the other hand, by inhibiting Th function or downregulating infected cell MHC- I antigen expression, indirectly inhibiting the production of CTL effector cells and their effective function, predisposing pregnant women to severe viral infections.
Viral infection of the embryo can directly affect fetal development and cause intrauterine growth restriction in the early and middle stages of pregnancy. Viral infection of the placenta causes placental dysfunction and non-uniform and mixed intrauterine fetal growth restriction. In 90% of symptomatic infants, sequelae are left behind.
Clinical features: small trunk size, hepatosplenomegaly, jaundice, thrombocytopenia, microcephaly, chorioretinitis, auditory and visual impairment and mental retardation in affected infants. Hearing loss is the most common neurological lesion of HCMV intrauterine infection.
Treatment and prevention: Acyclovir is the most widely used clinical drug against HCMV infection, but it is not suitable for use in pregnant women because of its toxic side effects. Vaccines cannot reduce the exclusion rate of HCMV, and the safety of live vaccines needs further confirmation. Therefore, so far there is still no safe and effective treatment for HCMV infection, and prenatal diagnosis is an effective way to prevent HCMV infection in utero.