Teratogenic Effects and Outcomes of Congenital Oropouche Virus Infection: Current Evidence, Pathophysiological Mechanisms, and Research Priorities

Background: Oropouche virus (OROV), an Orthobunyavirus endemic to Latin America, has recently emerged as a pathogen of concern in pregnancy following reports of vertical transmission, fetal demise, congenital anomalies, and neonatal disease. The unprecedented 2023–2025 outbreaks in Latin America have expanded the geographic distribution of OROV and renewed concerns regarding its potential as an emerging human teratogen. Methods: We conducted a narrative comprehensive review of the literature focusing on epidemiology, maternal–fetal transmission, placental infection, experimental models, fetal and neonatal outcomes, and comparisons with other congenital arboviral infections. Results: Increasing evidence supports the ability of OROV to infect the placenta, cross the maternal–fetal interface, and invade fetal tissues. Human cases have documented miscarriage, stillbirth, fetal demise, microcephaly, ventriculomegaly, cerebral atrophy, corpus callosum abnormalities, posterior fossa defects, arthrogryposis, and neonatal death following maternal infection. Viral RNA and OROV-specific antibodies have been detected in placental, fetal, and neonatal samples, providing direct evidence of congenital infection. Experimental studies using trophoblast cultures, placental organoids, neural progenitor cells, brain organoids, and animal models have confirmed placental susceptibility, vertical transmission, fetal neurotropism, and disruption of neurodevelopment. The congenital phenotype shares important similarities with congenital Zika syndrome and other neurotropic arboviral infections. Conclusions: OROV is newly and increasingly recognized as a vertically transmissible neurotropic arbovirus with potential teratogenic effects. Although biological plausibility is supported by converging clinical and experimental findings, prospective epidemiological studies are urgently needed to quantify risks, identify determinants of fetal injury, and define long-term outcomes among affected children.