Rubella IgM antibodies in sera from infants born after maternal rubella later than the 12th week of pregnancy.

The outcome of 338 pregnancies complicated by serologically confirmed rubella after the 12th week of gestation is reported. Therapeutic abortions were performed on 93 women, 1 pregnancy resulted in a spontaneous abortion and 5 in stillbirths. Cord blood or a sample collected at an age of 0--2 months from 209 liveborn infants were tested for rubella IgM antibodies after sucrose density gradient ultracentrifugation. Such antibodies were detected in samples from approximately 33% of infants born after maternal rubella in the 4th and 5th month of gestation, but only in 11% of infants born after maternal rubella later in pregnancy. The classical symptoms of congenital rubella were not observed with the possible exception of a suspected unilateral hearing loss in 1 infant born after maternal rubella in the 5th month of pregnancy.