Sonographic findings in fetal viral infections: a systematic review

Abstract

Viral infections are a major cause of fetal morbidity and mortality. Transplacental transmission of the virus, even in subclinical maternal infection, may result in a severe congenital syndrome. Prenatal detection of viral infection is based on fetal sonographic findings and polymerase chain reaction to identify the specific infectious agent. Most affected fetuses appear sonographically normal, but serial scanning may reveal evolving findings. Common sonographic abnormalities, although nonspecific, may be indicative of fetal viral infections. These include growth restriction, ascites, hydrops, ventriculomegaly, intracranial calcifications, hydrocephaly, microcephaly, cardiac anomalies, hepatosplenomegaly, echogenic bowel, placentomegaly, and abnormal amniotic fluid volume. Some of the pathognomonic sonographic findings enable diagnosis of a specific congenital syndrome (eg, ventriculomegaly and intracranial and hepatic calcifications in cytomegalovirus, eye and cardiac anomalies in congenital rubella syndrome, limb contractures and cerebral anomalies in varicella zoster virus). When abnormalities are detected on ultrasound, a thorough fetal evaluation is recommended because of multiorgan involvement.

Target audience: Obstetricians & Gynecologists, Family Physicians.

Learning objectives: After completion of this article, the reader should be able to recall that both clinical and subclinical maternal viral infections can cross the placenta, explain that there are specific sonographic findings along with laboratory findings to detect infectious agents, and state that when sonographic abnormalities are detected fetal viral infections need to be considered.