Viral threats to pregnancy: Global health risks in the era of pandemics

Pregnancy represents a uniquely vulnerable period during which viral infections can exert profound effects on maternal health, placental function, and fetal development. Over the past 30 years, emerging and re-emerging viruses, including flaviviruses, coronaviruses, poxviruses, orthomyxoviruses, paramyxoviruses, and filoviruses, have repeatedly demonstrated their capacity to disrupt pregnancy through diverse mechanisms that extend far beyond classical teratogenic outcomes. Nearly every major viral outbreak has revealed a critical gap in our understanding of maternal susceptibility during pregnancy. In this review, we will examine how emerging and re-emerging viruses threaten pregnancy across multiple biological scales, ranging from congenital infection, placental dysfunction, maternal immune dysregulation, and infertility, focusing on modern day viruses from a range of families. Understanding the mechanisms by which reproductive health can be impacted by these viruses and integrating this knowledge in developing care, prevention, and intervention strategies tailored to pregnancy and reproduction should be a foundational part of global health and preparedness.