Table 1.

Avidity index of anti-CMV IgG at two different gestation times in relation to prenatal diagnosis carried out by PCR in amniotic fluid and pregnancy outcomes in pregnant women at risk of transmitting a CMV infection and in a control population

Classification of AI of:nNo. of PCR-positive prenatal diagnoses of amniotic fluidNo. of infected fetuses or newbornsSNS (%)aSPE (%)bPPV (%)cNPV (%)d
Women at risk
 After 6–18 weeks of gestation10057.526.3100
  Low381710
  Moderate620
  High2630
  Not determinablee 610
 At time of amniocentesis (21–23 weeks)6060.618.890.9
  Low32126
  Moderate631
  High3273
  Not determinablee 610
Control population
 High (IgM negative)2000
  • a SNS, sensitivity (true positives/total infected fetuses or newborns × 100).

  • b SPE, specificity (true negatives/total uninfected fetuses or newborns × 100).

  • c PPV, positive predictive value (true positives/true positives + false positives × 100).

  • d NPV, negative predictive value (true negatives/true negatives + false negatives × 100).

  • e Not determinable because of anti-CMV IgG levels too low to determine AI.