PRIMARY INFECTION WITH CYTOMEGALOVIRUS DURING PREGNANCY

Abstract

Since the majority of postnatal cytomegalovirus (CMV) infections are unrecognized, the risk to the fetus of primary CMV infection at various times during pregnancy has not been meticulously assessed. During a prospective study of over 3000 pregnant teenagers, 8 patients with primary CMV infection defined as virologic as well as serologic conversion from negative to positive, were identified and followed. Asymptomatic primary infection occurred during the 1st trimester in one patient, during the 2nd trimester in 4 patients, and during the 3rd trimester in 3 patients. All 8 infants were asymptomatic but 4 (50%) were congenitally infected; all 3 neonates of the 3rd trimester converters and one of the 4 infants of the 2nd trimester converters. The single 1st trimester converter delivered an uninfected infant at term despite cytomegaloviremia during the 1st and 2nd trimesters as well as consistent viruria and intermittent positive throat and cervical cultures throughout her pregnancy. Placenta cultures of 6 converters resulted in one CMV isolate from an infected neonate born to a 3rd trimester converter. Primary CMV infection during pregnancy results in an infected infant in a significant percentage of patients, particularly if the infection occurs during the 3rd trimester. Nevertheless, primary CMV infection can occur during any trimester without resulting in an infant with any of the stigmata of cytomegalic inclusion disease at birth.