Diagnosis of Infections in Fetus: Ultrasound and Invasive Techniques

Abstract

Infections in pregnancy may lead to fetal morbidity and mortality. The major infections which can be transmitted from the mother to the fetus and can probably result in adverse consequences in the prenatal period include toxoplasmosis, rubella, cytomegalovirus (CMV), syphilis, parvovirus, and varicella. Factors determining the risks of transplacental transmission and associated fetal adverse events include the period of gestation at which transmission occurs and the immunity status of the mother. No single modality can diagnose all fetal infections and consequently prenatal diagnosis of fetal manifestations of infections is frequently made by fetal sonography and serology to identify the specific infectious agent. Ultrasound is now considered the safest and least invasive primary tool for the detection and monitoring of antenatal infection. Major findings in cases of fetal infection are observed in the central nervous system and heart with parenchymal calcifications, pleural/pericardial effusions, ascites, fetal growth restriction, oligo-/polyhydramnios and placentomegaly being frequently seen. Various diagnostic interventions are also performed under ultrasound guidance such as amniocentesis to determine underlying etiology and cordocentesis to detect fetal anemia. Knowledge of the various diagnostic modalities is required for appropriate counseling of the couple and for optimal treatment.