In addition, we have reported that the rate of change in the CMV IgG avidity index per 4 weeks, which was defined as the “Δ avidity index”, of >10% yielded 100% PPV for predicting congenital CMV infection among pregnant women with positive or equivocal tests for CMV IgM, together with an initial CMV IgG avidity index of <40% [13]. This evidence concerns the gene CD40LG and cytomegalovirus infection.