Clinical rubella reinfection during pregnancy in a previously vaccinated woman.

We report a documented case of clinically apparent rubella reinfection during pregnancy with rubelliform rash and fever followed by lymphodenopathy at the 18th week of gestation, in a previously vaccinated woman with haemagglutination inhibition (HI) antibody titre of 1:32. The serological tests results (including neutralizing antibodies) demonstrated a significant rise in her rubella specific IgG level with strongly positive IgM reactivity. In addition, rubella-specific IgG antibody avidity testing displayed high avidity index (53-88%) typical of rubella reinfection. Umbilical cord blood, drawn by sonographic-guided cordocentesis at 24 weeks' gestation, was found to be negative for rubella-specific IgM antibody. The pregnancy was continued to term, and a healthy infant was born.