Evaluation of pregnant women exposed to respiratory viruses.

Prenatal patients are often exposed to respiratory viruses at home and at work. Understandably, these patients may be concerned and want immediate answers and advice from their physicians. While most women who are exposed to chickenpox are immune, serologic testing can be performed and susceptible patients can be treated with varicella-zoster immune globulin. If the prenatal patient is infected with the varicella-zoster virus, the risk of fetal manifestations is less than 2 percent. Women who have been exposed to fifth disease can undergo serologic testing to determine the likelihood of infection. If the prenatal patient becomes infected with fifth disease during the first 20 weeks of gestation, the risk of fetal manifestations is about 9 percent and includes nonimmune hydrops and death. Cytomegalovirus, which is the most common congenital infection, is generally asymptomatic in the mother. Infected fetuses have a 25 percent chance of developing early or late neurologic manifestations. The evidence of harm from other common respiratory viruses is inconsistent.