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
  Not determinablee 610
 At time of amniocentesis (21–23 weeks)6060.618.890.9
  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.