Serologic Diagnosis and Fetal Involvement in Maternal Rubella

Abstract

A series of pregnant women with clinical rubella or exposed to a rubella-like illness was studied in an effort to establish a diagnosis of rubella by serologic means. Serologic evidence of rubella could not be found in seven exposed women in whom clinical illness did not develop. A fourfold rise in antibody titer was demonstrated in 13 of 16 women with a rubella-like illness. Ten women underwent therapeutic abortions and rubella virus was recovered from nine of ten abortuses. Rubella virus was also isolated from the placenta and throat swab of the one infant delivered thus far from the women with first trimester rubella. The number of fetal cells infected with virus was determined in five fetuses and found to be between one per 1,000 and one per 250,000 cells. The findings indicate that a high proportion of fetuses are infected in serologically proven maternal rubella. The number of fetal cells infected by rubella virus is relatively small, a finding which supports the hypothesis that viral persistence in congenital rubella results from in utero establishment of clones of infected cells.