Maternal-fetal infections with human viruses

Abstract

The maternal immune system is modulated by many factors during pregnancy. The maternal-fetal transmission of viruses and its consequences is changing during the different phases of pregnancy. Gestational age is influencing the consequences of the contact with viruses and viral antigens. In addition to the factors of innate immunity, virus receptors, factors of elicited cellular and humoral immunotolerance, humoral and cellular fetal responses to viral antigens and sensitisation of fetal immune cells are modulated during pregnancy. The role of transplacental transport of nanoparticles, immunocomplexes by maternofetal active transport were shown to facilitate fetal damage during pregnancy. The viruses molecularly integrated into the sperm cells, or their passive adsorption to the sperm cells will be discussed in other chapters of the volume. Permissiveness of cytotrophoblasts or syncytiotrophoblasts to the virus is the simplest way of vertical maternofetal infections. Reactivation of the viruses in seropositive pregnants may facilitate the transfer of infective immunocomplexes into the fetal circulation. Molecular transcytosis was found to be an important route of vertical transmission of viruses discussed in an other chapter of the monograph. In the case of genital infections, the ascending infections may be the source of fetal damage. The definition of perinatal transmission is the virus contamination of the newborns during delivery. Breast feeding is an important risk factor in the case of several viruses. Available preventive and therapeutic measures are mentioned in the chapter.