How Fever in Early Pregnancy Causes Heart, Facial Birth Defects
Duke HealthResearchers have known for decades that fevers in the first trimester of pregnancy increase risk for some heart defects and facial deformities such as cleft lip or palate. Exactly how this happens is unclear. Duke researchers now have evidence indicating that the fever itself, not its root source, is what interferes with the development of the heart and jaw during the first three to eight weeks of pregnancy.