Pregnancy outcomes following rubella vaccination: a prospective study in the state of Rio de Janeiro, Brazil, 2001-2002.

BACKGROUND

A rubella mass vaccination campaign targeting 15-29-year-old women was performed in Brazil in 2001-2002. Rubella vaccination was contraindicated during pregnancy. A follow-up protocol was implemented for pregnant women who were vaccinated as well as their newborns. The risks of congenital rubella syndrome (CRS) and congenital rubella infection (CRI) after vaccination were assessed according to the pregnant women's immune status.

METHODS

This was a prospective, noncontrolled study of pregnancy outcomes in women vaccinated against rubella in the state of Rio de Janeiro, including clinical and laboratory evaluations.

RESULTS

Of 2292 reported pregnant women who were vaccinated, 1636 had known outcomes: there were 1577 newborns (96.4%), 52 miscarriages (3.2%), and 7 stillbirths (0.4%). Gestational age at vaccination was ≤ 5 weeks in 75% of the susceptible, vaccinated pregnant women. Nine newborns were positive for immunoglobulin M; 4 were born to susceptible pregnant women, for a 2.0% CRI rate (95% confidence interval, .5%-4.9%); 4 were born to vaccinated pregnant women with indeterminate or unknown status; and 1 had CRS, with a wild-type virus infection.

CONCLUSIONS

The absence of vaccine-related CRS cases further supports recommendations to not interrupt a pregnancy exposed to rubella vaccine virus. Monitoring pregnancy outcomes and CRI with vaccine virus can distinguish between wild-type and vaccine virus infections, especially in situations of viral circulation.