Evaluation of the Safety and Efficacy of Standard Intravenous Immunoglobulins in Pregnant Women With Primary Cytomegalovirus Infection

Human IVIG are offered monthly to consecutive enrolled pregnant women with confirmed primary CMV infection at any stage, for the prevention and treatment of fetal CMV infection. Primary infection is defined by positive CMV IgM antibodies with absent or low titres of CMV IgG antibodies, and either low (<40%) CMV IgG avidity indexes with positive CMV IgM AND IgG antibodies. In addition women with indefinite avidity index and positive CMV DNA detection in urine and/or blood samples are also considered for treatment. Standard human intravenous immunoglobulins were chosen for their safety and efficacy, well documented in other settings. IVIGs were used to perform all of the infusions in the study, undiluted after reconstitution, in accordance with instructions of the manufacturer. We chose to perform IVIG infusions using 0.5 g/Kg of body weight, to make sure that a dose of specific CMV IgG at least comparable with that carried by HIG were infused at each time point. Infusions last 4 to 5 hours, using a double lumen line to infuse approximately 1500 mL of either 5% glucose or saline solution in parallel with the undiluted IVIG preparation, to reduce the risk of infusion reactions.

CMV IgG and IgM antibodies and IgG avidity indexes are assayed before and after each IVIG infusion, within 15 minutes. Quantitative CMV DNA is amplified from whole blood and urine samples from pregnant women and neonates, using the Real-Time PCR, and on samples of amniotic fluid from women who required amniocentesis. The newborns will be followed for five years after delivery.