Small study: maternal parvovirus infection often asymptomatic: 4 of 25 women had symptoms.(Obstetrics)

HYANNIS, MASS. -- Parvovirus infection during pregnancy can be a contributing factor in heart failure and death for the developing fetus, but many women infected with parvovirus B19 experience no symptoms, a small, retrospective cohort study has shown.

The findings, which are contrary to previously published studies concluding that the majority of pregnant women with maternal parvovirus experience flulike symptoms, suggest that the incidence of parvovirus infection may be underreported and that women with unrecognized infection may not be getting appropriate monitoring.

The results also call into question the sufficiency of current strategies for managing and counseling parvovirus-infected pregnant women, Dr. Hyagriv Simhan said at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.

Dr. Simhan and his colleagues at Magee-Womens Hospital, Pittsburgh, gathered demographic, clinical, sonographic, testing, and outcome data on 25 pregnant women found to be infected with parvovirus B19 between 1998 and 2001.

Only 4 of the 25 women had exhibited any symptoms of infection. "The vast majority of women were diagnosed because their older, school-aged children showed signs of infection," Dr. Simhan noted.

In the study group, hydrops occurred in three cases, and fetal death was reported in four cases. "One of the hydrops cases resolved spontaneously, and one of the fetal deaths occurred despite reassuring sonographic testing within 1 week," Dr. Simhan stated.

The study identified a clear seasonal variation in disease incidence, with all cases occurring from January through June. An annual variation was also noted. Of the 25 documented infections, 14 occurred in 1998 and 11 in 2001. No cases were reported in 1999 and 2000. The cases appeared to be geographically clustered in school district patterns.