Measles, mumps and rubella virus infection in pregnancy. Possible adverse effects on pregnant women, pregnancy outcome and the fetus

Measles, mumps and rubella are common childhood diseases. Therefore, frequent and intense contact with children of preschool age may be associated with a higher infection risk for childcare providers. This overview summarizes current knowledge on possible adverse effects of these infections on pregnant women, pregnancy outcome and the fetus. Acute rubella or mumps virus infections are apparently not more severe in pregnant than non-pregnant women. In contrast, measles virus infection in pregnancy is linked to a higher incidence of pneumonitis and hospitalization. Evidence of congenital defects due to fetal infection is only provided in case of rubella virus infection in early pregnancy. Following rubella virus infection in the first trimester an increased fetal loss rate was reported. In 1966, a prospective study showed also a significant association between maternal mumps in the first trimester and an increased risk of abortion. But other investigators could not confirm this association. Measles and rubella but not mumps virus infections are linked to an increased premature birth rate. Occurring in late pregnancy, all three infections can result in birth of an infected infant. But severe disease occurs rarely and is mostly reported for premature infants with early neonatal measles. Preventive measures, aimed to reduce the risk of infection or severe complications for pregnant childcare providers, should consider the individual history of the employee (e.g. previous immunizations or antibody test results), the current epidemiological situation and possible interventions like passive immunization in case of exposure to measles.