Prenatal Ultrasound Limited in Congenital Cytomegalovirus
Positive predictive value of ultrasound abnormalities is only 35 percent
MONDAY, April 14 (HealthDay News) -- In women who contract primary cytomegalovirus infection during pregnancy, ultrasound predicts whether their infants will have symptomatic congenital cytomegalovirus in only one-third of cases, according to research published in the April issue of the American Journal of Obstetrics & Gynecology.
Brunella Guerra, M.D., of the University of Bologna in Bologna, Italy, and colleagues investigated the utility of prenatal ultrasound in predicting symptomatic congenital cytomegalovirus infection in exposed fetuses. The researchers examined sonograms of 650 fetuses from mothers with primary cytomegalovirus infection, correlating results to fetal or neonatal outcomes. Infection status of infants was assessed using viral urine isolation at birth or cytomegalovirus tissue inclusions at autopsy.
Ultrasound visualized abnormalities in 51 of the 600 mothers with primary infection (8.5 percent), and in 23 of 154 congenitally infected fetuses (14.9 percent). Of congenitally infected fetuses/newborns, 55 percent were classified as symptomatic. The positive predictive value of ultrasound in predicting symptomatic congenital infection in fetuses exposed in utero was 35.3 percent.
"The limitations of ultrasonography in identifying predictive markers for adverse fetal outcome are well known," write the authors, explaining that "only fetuses with severe cytomegalovirus infection will show obvious ultrasound abnormalities, whereas more subtle or non-specific ultrasound features are likely to escape detection."