Pregnancy losses not increased: no fetal vaccinia with smallpox vaccine exposure.(Obstetrics)

ATLANTA -- No cases of fetal vaccinia or increases in pregnancy losses have been found after smallpox vaccination during pregnancy, according to an interim analysis of data from the National Smallpox Vaccine in Pregnancy Registry.

There was no detectable increase in the overall rate of congenital abnormalities, although five infants were born with major birth defects out of 185 live births.

It is too early to draw conclusions regarding individual defects, given the small population studied, Dr. Margaret Ryan said at a meeting of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.

Overall, the data reviewed to date are reassuring, said Dr. Ryan, director of the Defense Department's Naval Health Research Center in San Diego.

The primary objective of the registry is to assess the risk of fetal vaccinia, a rare but serious infection of the fetus, which is thought to occur after maternal viremia and is manifested by skin lesions and internal organ involvement.

According to information from the registry, 226 military women and 10 civilians were exposed to smallpox vaccine in pregnancy. The mean age was 23 years, 6% reported prior vaccination, and for 60%, this was their first pregnancy.

Among the 236 women, there were 185 live births, including 1 set of twins; 14 ongoing pregnancies; and 38 pregnancy losses. Among the 38 losses, there were 2 ectopic pregnancies, 11 elective abortions, 23 spontaneous abortions, and 2 stillbirths.