Rubella virus infection during the first months of pregnancy can cause miscarriage or birth defects in the foetus. It is important that a woman planning to become pregnant, who has not caught rubella, is vaccinated (at least three months before the planned pregnancy). In Poland, vaccination is obligatory in the vaccination calendar. It is advisable to check the antibody level before pregnancy and, if necessary, administer a booster dose.

The most dangerous form of primary rubella infection is during the first eight weeks of pregnancy - this is when the baby's internal organs are forming. The defects that rubella can cause include: eye disorders, e.g. glaucoma, cataracts; hearing disorders, e.g. deafness, hydrocephalus, mental retardation, deformities of the arms and legs, heart defects, liver damage etc. Infection after the 16th week of pregnancy usually does not cause birth defects in the child.

Primary CMV infection with cytomegalovirus (i.e. infection that first occurs during pregnancy) in pregnant women is dangerous and can result in foetal malformations and impaired psychomotor development of the child. The risk of CMV transmission during primary infection is about 30% Having CMV infection before pregnancy does not protect against re-infection, reinfection or reactivation of the virus, but protects the foetus from transmission of the infection in about 99% of cases.
During delivery, there is a risk of herpes virus (HSV) infection . Infection in the newborn may be limited to the eyes, skin and mouth. However, it can also affect the nervous system. If genital herpes is present, delivery is often by caesarean section.

Parvovirus B19 causes disease five (erythema contagiosum), a mild childhood illness. Pregnant women who have not previously contracted erythema contagiosum should avoid contact with sick people. Approximately 30% of pregnant women who become ill transmit the infection across the placenta to the foetus. Infection during the first trimester of pregnancy can result in miscarriage. There is also a risk of serious complications in the foetus, e.g. severe anaemia, generalised oedema, heart failure, myocarditis, death, which most often occurs in cases of infection acquired before 20 weeks of pregnancy. However, in the majority of children with confirmed intrauterine infection, complications are not found and development is normal.

Hepatitis B and C virus infections can cause infection in the newborn. Hepatitis B virus transmission is more common than C virus transmission (about 4%). Newborns of mothers infected with hepatitis B virus receive immunoglobulin at birth together with vaccination. There is no vaccine for the hepatitis C virus.