A 24-year-old primigravida at 14 weeks has hemoglobin 9.0 g/dL, MCV 64 fL, MCH 20 pg, serum ferritin 48 ng/mL, and HbA2 2.0%. Her partner has MCV 66 fL and HbA2 5.5%. What is the most appropriate counseling regarding thalassemia risk to the fetus?
- A 25% risk of Hb Bart hydrops fetalis
- B 25% risk of beta-thalassemia major
- C No increased risk of thalassemia major ✓
- D 50% risk of Hb H disease
Correct answer: C. No increased risk of thalassemia major
Explanation
The woman has alpha-thalassemia trait (microcytic hypochromic anemia, normal ferritin, normal/low HbA2). Her partner has beta-thalassemia trait (elevated HbA2 >3.5%). Since they carry different thalassemia traits, the fetus cannot inherit thalassemia major for either type. The child may inherit both traits as a double heterozygote but will not develop thalassemia major. Prenatal diagnosis for thalassemia major is not indicated.
Reference: Williams Obstetrics, 25th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.