Abstract
Introduction LAST YEAR we established that rubella virus may infect the first trimester human fetus and persist therein throughout pregnancy, virus being recoverable from newborn infants with signs of the rubella syndrome.1An interesting relationship between the isolation of rubella virus from the product of conception and the gestational age at the time of maternal rubella was elucidated.1Relevant findings of this study, based on materials from 68 women, are summarized in Table 1. The isolation rate was 14% in the first two weeks of pregnancy, reached a maximum of 73% between the fifth and sixth weeks, and decreased thereafter to 33%. Placental recoveries of virus exceeded fetal recoveries in each age category. Moreover, most of the fetal isolates were associated with maternal rubella occurrences from the third through the eighth week of pregnancy, whereas persistent placental infection was common with exposures after the eighth week of pregnancy.