The IgG avidity value for the prediction of congenital cytomegalovirus infection in a prospective cohort study.

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.