The Prognostic Value of Ultrasound Abnormalities and Biological Parameters in Blood of Fetuses Infected with Cytomegalovirus

Cytomegalovirus (CMV) is the major cause of congenital viral infection. Primary infection occurs in 1% to 2% of pregnancies in industrialized countries, with a vertical transmission rate of 30% to 40%. The goal of this retrospective observational study, carried out at two fetal medicine units in Paris, was to document the prognostic value of ultrasonographic abnormalities and selected biological parameters in the blood of CMV-infected fetuses. Information was collected prospectively by fetal blood sampling (FBS) from 73 infected fetuses whose amniotic fluid tested positive by the polymerase chain reaction technique. FBS was done to determine the platelet count, plasma levels of aminotransferases and gamma-glutamyl transpeptidases, the presence of viremia, and specific fetal immunoglobulin M. Targeted ultrasonography was carried out at 2-week intervals. Maternal primary infection took place during the first trimester in a large majority of these 73 cases. Nearly half the pregnancies (48%) had a poor outcome. Thirty-nine pregnancies continued to term. Women chose to end 32 pregnancies, and there were two intrauterine fetal deaths. On univariate analysis, the only factors associated with a poor outcome were thrombocytopenia and the presence of any ultrasound abnormality. These factors remained significant and independent predictors of a poor outcome on multivariate analysis. Univariate logistic regression analysis yielded odds ratios for a poor outcome of 1.24, 7.2, 22.5, and 25.5, respectively, for each 10,000/mm 3 decrease in platelets, noncerebral ultrasound abnormalities, any abnormal ultrasound study, and cerebral abnormalities. The same predictors remained significantly associated with a poor outcome on multivariate analysis. The investigators believe that, despite a procedure-related loss rate of up to 3%, FBS to determine the fetal platelet count could be a useful accompaniment to prenatal ultrasonography in fetuses diagnosed as having CMV infection. The findings might be especially relevant when fetal ultrasonography fails to detect cerebral abnormalities.