Introduction & Objective: Rubella is a disease caused by the rubella virus and is usually mild and self-limiting. Infection of a developing fetus is serious and important because the child may be born with congenital rubella syndrome. Its symptoms include mental retardation, heart defects, cataract, etc. In 2003, mass vaccination against measles and rubella in individuals 5-25 years old was done. One of the main objectives of this study was to survey congenital rubella infection status with the presence of IgM antibodies against rubella virus in cord blood samples and also the immunity assessment of maternal IgG antibodies against rubella virus in the samples.

Materials & Methods: In this cross-sectional study 358 cord blood samples were collected in hospitals affiliated to Tehran University of Medical Sciences in 2008-2009. The collected samples were analyzed by two ELISA methods for detection of IgG and IgM antibodies and RT-nested PCR tests on samples of IgG–negative and IgM-positive. In this study two groups of mothers were tested, one consisted of the ones< 29 years old (at the time of vaccination) with the frequency of 70.9% and the other one was those who were>29 with the frequency of 29.1%.

Results: The mean age of subjects was 22.6 years old. Out of 358 samples, 326 (91.1%) were IgG positive, and 10 (2.8%) were IgM positive against rubella virus. All of the samples with negative result for IgG antibody, and positive result for IgM antibody against rubella virus were tested for the presence of rubella genome with RT-nested PCR method. None of these samples were positive according to the presence of the virus genome.

Conclusion: According to the high immunity of mothers, the probability of congenital rubella transmission is low, but because of low immunity of mothers being >29 years old, it is highly reccommended to upgrade the age of vaccination to 28.