Risk of congenital cytomegalovirus infection in children born to women with IgG avidity in the grey zone during first trimester of pregnancy.

INTRODUCTION: Cytomegalovirus (CMV) is the most common congenital viral infection and is regarded as the leading nongenetic cause of sensorineural hearing loss. Currently, international consensuses discourage prenatal screening of pregnant women. However, in few countries mainly in Southern Europe, screening of pregnant women for CMV infection is common practice. Management of women found with IgG+/IgM + and IgG avidity titers in the grey zone during first trimester causes significant stress to both families and health care workers.

PATIENTS AND METHODS: Pregnant women referred to our outpatient clinic with the diagnosis of acute CMV infection (IgM+/IgG+) during early pregnancy (gestational age ≤ 14 weeks) and IgG avidity in the grey zone were prospectively followed. The administration of CMV-HIG was offered and follow-up included fetal U/S, amniocentesis for CMV-DNA detection and MRI when appropriate. All neonates were examined by urine PCR and prospectively followed according to existing recommendations.

RESULTS: Ninety women (mean age 30.8 years) were retrospectively analyzed. Most (79.6%) received CMV-HIG. Four women terminated pregnancy (2 unrelated to CMV reasons and 2 because of CMV-positive amniotic fluid). Eighty-seven babies were born asymptomatic. Two newborns were diagnosed with congenital CMV infection. The overall transmission rate was 4.4%; 4.3 versus 5.6% for those receiving or not CMV-HIG. No adverse outcomes were detected during follow-up (median 24 months). Maternal age, parity, detection of maternal CMV-viremia upon diagnosis, delay between diagnosis and consultation, gestational week of first consultation, administration of CMV-HIG and number of doses were not associated with the risk of vertical CMV transmission.

DISCUSSIONS: Vertical transmission of CMV infection in pregnancies with acute CMV-infection and IgG avidity titers in the grey zone during first trimester was 4.4%, higher than that in infants born post nonprimary infection (NPI) during pregnancy. More powered studies are needed to prove a significant reduction in transmission using CMV-HIG.