Severe Fetal Symptomatic Infection from Human Cytomegalovirus following Nonprimary Maternal Infection: Report of Two Cases

Abstract

Introduction: Human cytomegalovirus (HCMV) is the most common congenital infection, especially severe after a maternal primary infection; sequelae in neonates born to mothers experiencing a nonprimary infection have been already reported. Hereby, two cases of severe fetal HCMV disease in seroimmune gravidas referred to our Unit are described. Cases Presentation: Case 1: A fetus at 21 weeks’ gestation with signs of anemia and brain abnormalities at ultrasound, described at magnetic resonance (MR) imaging as ependymal irregularity and bilateral asymmetric parenchymal thinning; amniotic fluid sample was positive for HCMV although the woman had a previous immunity; after termination of pregnancy, autopsy demonstrated a thicken layer of disorganized neurons on the right cortical plate, while on the left, there was a morphological pattern coherent with polymicrogyria. Case 2: A fetus at 20 weeks’ gestation with anemia, moderate atrioventricular insufficiency, hepatosplenomegaly but no major cerebral lesions. Fetal blood was positive for HCMV, although unexpected for prepregnancy maternal immunity, and intrauterine transfusion was needed. A cesarean section at 34 weeks’ gestation was performed due to worsening condition of the fetus, who had a birthweight of 2,210 g and needed platelet transfusions, but MR examination and clinical evaluation were normal. Conclusion: The impact of nonprimary maternal infection on pregnancy outcome is unknown and fetal brain damage in HCMV seroimmune transmitter-mothers can occur as a consequence of maternal reinfection or reactivation for a hypotetic different role of HCMV-primed CD4+ or CD8+ T-cells in fetal brain, with progressive brain lesions coexistent in the first case and with severe unexpected anemia in the second case. A previous maternal HCMV immunity should not exempt to test anemic fetuses for such infection, nor to consider a potential transplacental transmission.