RT-PCR in the prenatal diagnosis of rubella. Report of 2 cases

Objective: To confirm the interest of the reverse transcription-coupled polymerase chain reaction (RT-PCR) in prenatal diagnosis of rubella.

Methods: Maternal blood, amniotic fluid and foetal blood specimens collected at 21 to 24 weeks of amenorrhea from two pregnant women with serologically proven rubella infection were tested by RT-PCR and cell culture for detection of rubella virus. Rubella virus-specific IgM antibodies were also assayed in foetal blood.

Results: In both cases, rubella virus was detected in foetal blood by RT-PCR and cell culture, whereas it was not detected in maternal blood. Rubella virus-specific IgM were also detected in foetal blood. In amniotic fluid specimens, rubella virus was detected by RT-PCR in one case and by cell culture in the other one. A termination of pregnancy was carried out in both cases.

Conclusions: RT-PCR is a rapid test. It could be useful to confirm foetal infection and could represent a criterion for considering a pregnancy termination. However, this technique which is not yet standardized for detection of rubella virus, needs further validation by additional studies.