Читать книгу Protocols for High-Risk Pregnancies - Группа авторов - Страница 113

The American College of Obstetricians and Gynecologists recommends initial screening of all populations with a complete blood count. This should be followed by reflex to hemoglobin electrophoresis in the presence of a microcytosis (low mean corpuscular hemoglobin or low mean corpuscular volume) and among individuals of African, Mediterranean, Middle Eastern, Southeast Asian, or Indian descent. Hemoglobin electrophoresis is the gold standard for diagnosis of sickle cell disorders and thalassemias. Solubility tests, isoelectric focusing, and high‐performance liquid chromatography can fail to identify certain hemoglobinopathy traits that can have important reproductive consequences and therefore are generally not used for primary screening.

Beta‐thalassemia will be detected through a hemoglobin constitution of greater than 3.5% hemoglobin A2 and a variably elevated hemoglobin F because beta globin is not present in either of these hemoglobin variants. Alpha‐thalassemia trait may result in a normal hemoglobin electrophoresis and therefore requires diagnosis with DNA‐based testing, which should be pursued in the setting of a low mean corpuscular volume only after iron deficiency anemia and beta‐thalassemia have been excluded and usually after the patient’s partner is also found to be a thalassemia carrier.