Maternal infections with an increased risk of transmission to the foetus; a literature review

Abstract

Screening testing for infectious diseases with vertical transmission, from mother to foetus, decreases the prevalence of foetal malformations. The most common infections with teratogenic potential are found in the TORCH test (Toxoplasma, Other infections, Rubella, Cytomegalovirus, Herpes simplex virus). Early identification of these pathogens results in better neonatal outcomes. Most foetuses with congenital toxoplasmosis are asymptomatic or have no apparent birth defect, while the primary infection of pregnancy with varicella-zoster virus (VZV) can lead to congenital foetal abnormalities with devastating consequences. Treponema pallidum can easily infect the placenta, with transplacental transmission to the foetus that can occur from about 9-10 weeks of gestation. Also, hepatitis B and C are the most common causes of chronic viral hepatitis in children and adults. In the case of HIV-positive pregnant women, the early association of ART, together with the choice of birth by scheduled caesarean section and the complete lack of breastfeeding determine expected neonatal results, the risk of vertical transmission decreasing up to 1-2%. Primary rubella infection during pregnancy can significantly affect foetal development, as does Herpes simplex virus (HSV) infection, but if it occurs as close as possible to birth, the disease may be self-limiting with mild forms. No teratogenic agent should be described qualitatively, as a teratogenic exposure includes not only the agent but also the dose and time of pregnancy when the exposure will occur. Screening tests are recommended to be performed both preconceptionally and during pregnancy.