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تعداد آیتم قابل مشاهده باقیمانده : -21 مورد

Reproductive counseling and management for possible alpha thalassemia major (ATM)

Reproductive counseling and management for possible alpha thalassemia major (ATM)
Alpha0 thalassemia refers to complete absence of alpha globin chains. Identification of alpha0 thalassemia carrier status is a critical step that is often performed incorrectly. Many clinicians mistakenly believe that a normal hemoglobin electrophoresis or HPLC excludes carrier status; it does not. Refer to UpToDate for details of parental testing, which includes:
  • Maternal CBC, ferritin, and hemoglobin analysis (HPLC, electrophoresis, IEF)
  • Correction of maternal anemia (ferritin <30 ng/mL) prior to interpretation of protein-based methods
  • MCV <80 fL, MCH <27 pg, and Hb A2 ≤3.5% is consistent with alpha thalassemia carrier status and necessitates DNA testing, typically by PCR.

ATM: alpha thalassemia major; CBC: complete blood count; CVS: chorionic villus sampling; DNA: deoxyribonucleic acid; Hb: hemoglobin; HPLC: high-performance liquid chromatography; IEF: immunoelectrophoresis; IVF: in vitro fertilization; MCA: middle cerebral artery; MCH: mean corpuscular hemoglobin; MCV: mean corpuscular volume; MoMs: multiples of the mean; PCR: polymerase chain reaction; PGT: preimplantation genetic testing; PSV: peak systolic velocity; PUBS: percutaneous umbilical blood sampling.

* Counseling can include possible pregnancy outcomes, methods of testing and screening (and differences between testing and screening), options if ATM is diagnosed, maternal and fetal risks of continuing or terminating the pregnancy, options for future childbearing, and other parental concerns.

¶ PUBS is typically performed at a specialized center from week 18 onwards. It can be used to obtain DNA to confirm the molecular diagnosis if needed, to assess fetal anemia, and to provide intrauterine transfusions if appropriate. Hb electrophoresis on fetal blood may also identify an affected pregnancy in those cases with an over representation of Hb Barts. If intrauterine transfusions are used, these should be started as soon as technically possible (18 weeks at most centers), and PUBS with fetal transfusion should be repeated every 2 to 3 weeks until birth.

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