Identification of pregnancies at risk from cytomegalovirus infection.

The fluorescent antibody technique was used for the identification of specific cytomegalovirus IgM in the sera of twenty-four of 1065 unmarried pregnant women. Seventeen of them were followed to term and five infected infants were identified. Two other infants had CMV IgM in neonatal serum samples but virus excretion was not demonstrated. The congenital infection rate in this study was 5.3 per 1000 births by virus excretion and 7.9 per 1000 if cases with specific IgM are included; from previous studies a rate of 8.8 per 1000 was expected. The reasons for the lack of relationship between specific IgM in the mothers' serum and infected babies is discussed.