Background: Cytomegalovirus (CMV) causes congenital infection with high mortality and morbidity rates in affected neonates.
Objectives: To evaluate the maternal IgG avidity value for the prediction of congenital CMV infection.
Study design: The serum IgG avidity in all mothers was measured, and the urine of their neonates was assessed for CMV DNA in a prospective cohort study.
Results: Of 759 women with a positive test for CMV IgG, 14 had congenital CMV infection. CMV IgG avidity indices in the congenital infection group (median 35.1%) were significantly lower than those in the non-congenital infection group (70.4%). A cutoff value of <40% IgG avidity index with 96.1% specificity and 64.3% sensitivity for congenital infection was determined by receiver operating characteristic curve analyses. The highest sensitivity (88.9%), 96.2% specificity, 27.6% positive predictive value, 99.8% negative predictive value, and 96.1% accuracy were found when IgG avidity was measured in <28 weeks of gestation.
Conclusion: The IgG avidity measurement with a cutoff value of <40% IgG avidity index might be helpful in predicting congenital CMV infection, especially in <28 weeks of gestation.