Can congenital CMV be prevented?

Yes, possibly with hyperimmune globulin. So say results of a small, prospective study of the drug in pregnant women with primary cytomegalovirus (CMV) infection. The authors caution, however, that a larger randomized, controlled trial is needed to confirm their findings.

The study, by researchers from the Congenital Cytomegalovirus Collaborating Group, enrolled 181 pregnant women who had been infected with CMV at least 6 weeks previously. Of the 79 who had CMV-positive amniocenteses, 31-the "therapy" group-received a single dose of 200 U/kg of hyperimmune globulin. Of the 102 women who did not undergo amniocentesis, 37-the "prevention" group- received 100 U/kg of hyperimmune globulin monthly until delivery.

Only one (3%) woman in the therapy group gave birth to an infant with CMV, versus seven of the 14 women who had CMV-positive amniocenteses but chose to have no therapy (OR 0.02;CI -∞ to 0.15; P<0.001). Six (16%) of the women in the therapy group had CMV-positive infants, versus 19 of 47 (40%) who did not receive hyperimmune globulin (OR 0.32; CI 0.10–0.94; P=0.04).

Nigro G, Adler SP, La Torre R, et al., for the Congenital Cytomegalovirus Collaborating Group. Passive immunization during pregnancy for congenital cytomegalovirus infection. N Engl J Med. 2005;353:1350-1362.