West Nile, A Pregnancy Danger? (cont.)

Pregnant women who have meningitis, encephalitis, acute flaccid paralysis, or unexplained fever in an area of ongoing WNV transmission should have serum (and cerebrospinal fluid [CSF], if clinically indicated) tested for antibody to WNV. If serologic or other laboratory tests indicate recent infection with WNV, these infections should be reported to the local or state health department, and the women should be followed to determine the outcomes of their pregnancies.

Evaluation of the Fetus in Pregnant Women with WNV Infection

If WNV illness is diagnosed during pregnancy, a detailed ultrasound examination of the fetus to evaluate for structural abnormalities should be considered no sooner than 2--4 weeks after onset of WNV illness in the mother, unless earlier examination is otherwise indicated. Amniotic fluid, chorionic villi, or fetal serum can be tested for evidence of WNV infection. However, the sensitivity, specificity, and predictive value of tests that might be used to evaluate fetal WNV infection are not known, and the clinical consequences of fetal infection have not been determined. In case of miscarriage or induced abortion, testing of all products of conception (e.g., the placenta and umbilical cord) for evidence of WNV infection is advised to document the effects of WNV infection on pregnancy outcome.

Evaluation of Infants Born to Mothers Infected with WNV During Pregnancy

When an infant is born to a mother who was known or suspected to have WNV infection during pregnancy, clinical evaluation is recommended (Box 1). Further evaluation should be considered if any clinical abnormality is identified or if laboratory testing indicates that an infant might have congenital WNV infection (Box 2).

Prevention of WNV Infection During Pregnancy

Pregnant women who live in areas with WNV-infected mosquitoes should apply insect repellent to skin and clothes when exposed to mosquitoes and wear clothing that will help protect against mosquito bites. In addition, whenever possible, pregnant women should avoid being outdoors during peak mosquito-feeding times (i.e., usually dawn and dusk).

Reported by: E Hayes, MD, D O'Leary, DVM, Div of Vector-Borne Infectious Diseases, National Center for Infectious Diseases; SA Rasmussen, MD, Div of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, CDC.

Source: Center for Disease Control (cdc.gov)

Last Editorial Review: 2/28/2004