Zika Virus Takes a Transplacental Route to Infect Fetuses: Insights from an Animal Model

Zika virus (ZIKV) has been linked to intrauterine growth restriction (IUGR), spontaneous miscarriage, and microcephaly in infants of women infected during pregnancy. To determine how ZIKV affects the fetus, we infected pregnant mice subcutaneously (mimicking a mosquito bite) with ZIKV. Multiple techniques revealed that ZIKV replicated within placental trophoblasts, fetal endothelial cells, and the fetal neocortex. We also noted severe placental defects, IUGR, and fetal death. Thus, our mouse model recapitulated ZIKV infection in human pregnancy and demonstrated that ZIKV can be transmitted from mother to fetus via the placenta.