Monitoring of human cytomegalovirus DNAemia during primary infection in transmitter and non-transmitter mothers.

BACKGROUND AND OBJECTIVES: It has been reported that maternal DNAemia is detectable in three quarters of pregnant women with acute/recent primary HCMV infections, with a higher median number of HCMV DNA copies/ml blood in transmitter as compared with non-transmitter mothers.

STUDY DESIGN: The kinetics of HCMV DNA in blood of transmitter vs non-transmitter pregnant women with primary HCMV infection was retrospectively analyzed from their first blood sampling at referral up to amniocentesis strictly performed at 19-21 weeks' gestation. Monthly monitoring of maternal HCMV DNAemia was performed up to prenatal diagnosis.

RESULTS: HCMV DNAemia was determined in 154 pregnant women. At amniocentesis, HCMV DNA in blood was positive in 42/50 (84.0%) amniotic fluid (AF) -positive and 21/104 (20.2%) AF-negative mothers (p<0.0001). The number of HCMV DNA copies/ml blood was not significantly different in AF-positive as compared with AF-negative mothers in the interval 0-30days post-infection (p=0.14). On the contrary, HCMV DNA load at 30-60days (p=0.03) and at 60-90days (p<0.001) after onset of infection was significantly different, as observed at amniocentesis (p<0.001). Three patterns (clearance, delayed decrease, and increasing) in both transmitter and non-transmitter mothers were observed. However, 79.8% AF- negative mothers cleared HCMV DNA in blood, while in AF-positive mothers increasing (44.0%) or persisting (40.0%) levels of DNAemia were observed.

CONCLUSIONS: The presence of viral DNA in maternal blood at amniocentesis is statistically associated with fetal HCMV infection. Increasing or persisting levels of maternal DNAemia during primary HCMV infection in pregnancy correlate with HCMV transmission to the fetus.