Prenatal diagnosis of congenital rubella infection and ultrasonography: a preliminary study

The aim of this study was to analyze the role of ultrasonography in the prenatal diagnosis of women with confirmed rubella infection in pregnancy.

We performed a retrospective, population-based study on 175 women referred to our Centre of Infectious Disease in Pregnancy of AOU Federico II for rubella infection, in the period between January 1999 and December 2009. In confirmed cases of infection we performed periodic ultrasonographic assessment of fetal anatomy looking for prenatal findings of rubeovirus infection. Neonatal outcomes were collected.

Among 175 women, 48 (27.4%) were confirmed cases, in 83 (47.4%) cases rubella infection remain suspected. The remaining 44 (25.1%) women were excluded to having rubella infection in pregnancy. No defined probable cases were found. Among children born to mother with confirmed rubella infection, 9 (18.7%) resulted infected by rubella virus. In particular 6 newborns (66% of the affected) were asymptomatic, two babies showed incomplete congenital rubella syndrome (CRS), due to the presence of deafness in the absence of other congenital abnormalities without showing any USG findings. Only one baby showed a complete CRS: USG prenatal rubella infection findings were IUGR, polydramnios, cardiomegaly, defects of atrial septum, hepatosplenomegaly, ascites, echogenic bowel, placentomegaly. USG specificity and sensitivity was 100% and 11% respectively.

USG has an important role in the detection rubella intrauterine infection in case of severe abnormalities. The obstetricians should understand the limitations of ultrasound in detection of deafness and minor abnormalities.