Thalassemia syndromes, hemoglobinopathies characterized by anemia secondary to genetic defects of hemoglobin, are the most common of the genetic blood disorders. The prevalence and severity of the thalassemia syndromes are population dependent, with the type of thalassemia seen dependent on racial background. The health care provider must recognize the woman at highest risk for thalassemia and initiate appropriate screening and diagnostic testing. The specific thalassemia dictates the potential maternal, fetal, and neonatal consequences of anemia, red blood cell dysfunction, and systemic oxygenation issues. This article discusses normal globin chain synthesis, diagnostic testing for thalassemia, plan of management, and implications for the woman and fetus.