Background.  Primary cytomegalovirus (CMV) infection during pregnancy is the leading infectious cause of congenital neurological disabilities. Early CMV infection carries a higher risk of adverse neonatal outcome (sensorineural hearing loss or neurological deficits). Intravenous hyperimmunoglobulin (HIG) therapy seems to be promising, but its efficacy needs further investigation.

Methods.  Since 2002, we have enrolled consecutively all pregnant women with early (ie, before gestational week 17) CMV infection. Beginning in 2007, all women were offered treatment with HIG (200 UI per kilogram of maternal weight, in a single intravenous administration). Outcome of infants was evaluated at the age of 1 year.

Results.  Of the 592 women with early primary CMV infection, amniocentesis for CMV DNA detection was performed for 446. Of the 92 CMV-positive fetuses, pregnancy was terminated for 24, HIG was administered to mothers of 31, and no treatment was received by mothers of 37. Fetuses of treated mothers did not differ from fetuses of nontreated mothers according to mother's age, gestational week of infection, CMV load, or detection of abnormal ultrasonography findings. At the 1-year evaluation, 4 of 31 infants with treated mothers (13%; 95% confidence interval [CI], 1%–25%) and 16 of 37 infants with nontreated mothers (43%; 95% CI, 27%–59%) presented with poor outcomes (P < .01, by the 2-tailed Fisher exact test).

Conclusions.  HIG treatment improved the outcome of fetuses from women who had primary CMV infection before gestational week 17.