Possible role of hyperimmunoglobulin in reducing the risk of maternal–fetal transmission of cytomegalovirus in the valacyclovir era: a case series

INTRODUCTION: Valacyclovir is the only treatment option during pregnancy which has been demonstrated to be effective within a randomized clinical trial for prevention of transplacental cytomegalovirus (CMV) transmission. However, the use of high dose intravenous hyperimmunoglobulin (HIG) could reduce the rate of vertical transmission according to some observational studies. CASES PRESENTATION: We report three peculiar cases in which high dose HIG was administered in substitution to or in addition to valacyclovir to reduce the risk of transplacental transmission of CMV. Two were immunocompromised pregnant women-one with recurrent CMV reactivations due to solid organ transplant-related immunosuppression and one with primary CMV infection and lack of IgG production due to anti-CD20 treatment for multiple sclerosis-in which HIG was co-administered with valacyclovir. The third case involved an immunocompetent pregnant woman to whom HIG was administered in substitution to valacyclovir due to severe gastrointestinal side effects related to the latter medication. In all cases, the treatment was well tolerated and the newborns tested negative for CMV at birth. CONCLUSION: Together, these cases give an interesting perspective on the possible role of HIG in selected immunocompromised pregnant women with primary and non-primary CMV infection in addition to valacyclovir, and in immunocompetent pregnant women unable to tolerate valacyclovir or in whom the drug is contraindicated.