Teratogenic parasites: disease mechanisms and emerging study models

Toxoplasma gondii, Plasmodium falciparum, and Trypanosoma cruzi are important human pathogens that cause severe disease in the mother and fetus during pregnancy.Global incidence of congenital complications due to these parasites varies dramatically depending on overall transmission rates and the immune status of the population.A primary means of disease that unifies these three parasites is causing inflammation in and around the placenta, which can increase the ability of the parasite to be transmitted to the fetus.Newly emerging models of placental development have great potential to revolutionize our understanding of parasite–placenta interactions. These include placental organoids and trophoblast stem cells.For each of these parasites we speculate about the importance of congenital transmission in its evolutionary history in light of evolutionary theory of vertical transmission. Congenital infections are a leading preventable cause of pregnancy complications impacting both mother and fetus. Although advancements have been made in understanding various congenital infections, the mechanisms of parasitic infections during pregnancy remain poorly understood. This review covers the global incidence of three parasites capable of congenital transmission – Trypanosoma cruzi, Plasmodium spp., and Toxoplasma gondii – and the state of research into their transplacental transmission strategies. We highlight technological advancements in placental modeling that offer opportunities to reveal how parasites cause gestational pathology. Additionally, we discuss the likelihood that selective adaptation contributed to the evolution of mechanisms that facilitate placental infection. These insights provide a foundation for understanding the progression and pathology of congenital parasitic diseases and identifying future research directions. Congenital infections are a leading preventable cause of pregnancy complications impacting both mother and fetus. Although advancements have been made in understanding various congenital infections, the mechanisms of parasitic infections during pregnancy remain poorly understood. This review covers the global incidence of three parasites capable of congenital transmission – Trypanosoma cruzi, Plasmodium spp., and Toxoplasma gondii – and the state of research into their transplacental transmission strategies. We highlight technological advancements in placental modeling that offer opportunities to reveal how parasites cause gestational p