The mechanism (s) by which neonates testing positive for coronavirus disease 2019 (COVID-
19) acquire their infection has been largely unknown. Transmission of the etiological agent …

Flaviviruses such as dengue (DENV), yellow fever (YFV), West Nile (WNV), and Zika (ZIKV)
are human pathogens of global significance. In particular, DENV causes the most prevalent …

Context.—Perinatal death is an increasingly important problem as the coronavirus disease
2019 (COVID-19) pandemic continues, but the mechanism of death has been unclear …

Background The human placenta has been traditionally viewed as sterile, and microbial
invasion of this organ has been associated with adverse pregnancy outcomes. Yet, recent …

Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) transmitted primarily by Aedes
mosquitoes. ZIKV can be transmitted to humans by non-vector borne mechanisms such as …

Why certain viruses cross the physical barrier of the human placenta but others do not is
incompletely understood. Over the past 20 years, we have gained deeper knowledge of …

Hofbauer cells are placental villous macrophages of fetal origin that are present throughout
pregnancy. Although Hofbauer cell populations are antigenically and morphologically …

Viral infections during pregnancy are associated with adverse pregnancy outcomes,
including maternal and fetal mortality, pregnancy loss, premature labor, and congenital …

Since the beginning of the pandemic, few papers describe the placenta's morphological and
morphometrical features in SARS-CoV-2–positive pregnant women. Alterations, such as low …

The placenta functions as a shield against infection of the fetus. The innate and adaptive
immune defenses of the developing fetus are poorly equipped to fight infections. Infection by …