Management of Alpha Thalassemia HbH Disease in Pregnancy

Pre-Pregnancy Counseling and Risk Assessment

Genetic counseling is essential before conception to discuss the 25% risk of severe disease if the partner is also a carrier, which is typically fatal 2
Partner screening is mandatory when a woman with HbH disease plans pregnancy, including CBC with MCV measurement, and if MCV <80 fL, proceed with hemoglobin analysis and DNA testing 2
Prenatal diagnosis options should be discussed, including chorionic villus sampling at 10-13 weeks or amniocentesis at 15-20 weeks for DNA-based testing 2

Pregnant women with HbH disease require close monitoring with CBC every 3-6 months to assess for worsening hemolytic anemia and determine transfusion needs, with particular attention to maintaining adequate hemoglobin levels for optimal fetal growth 1
Monitor CBC every 3-6 months throughout pregnancy to assess the degree of hemolytic anemia, as HbH disease severity can vary significantly 1
Measure serum ferritin to exclude concurrent iron deficiency before initiating iron supplementation, as inappropriate iron supplementation in HbH disease can worsen hemosiderosis 2

Ultrasound surveillance in the late second and early third trimester is critical to detect hydrops fetalis if the fetus has inherited severe alpha thalassemia 2
Middle cerebral artery Doppler should be used to assess for fetal anemia in cases of suspected hydrops fetalis 1
Monthly fetal growth monitoring scans from viability are recommended to ensure adequate fetal development 3

Increased risk of gestational diabetes, preeclampsia, and hypertension should be anticipated, similar to other thalassemia syndromes 4, 5
Spontaneous miscarriage and fetal loss occur in 9-33.3% of pregnancies in women with thalassemia 4, 5
Preterm births occur at increased rates due to underlying maternal or obstetric complications 4, 5

Prophylaxis with heparin or low-molecular-weight heparin is indicated, particularly if the patient has undergone splenectomy, as this significantly increases thrombotic risk 4, 5

Cesarean delivery rates are higher due to fetopelvic disproportion, osteoporosis, or maternal complications 4, 5
Pregnancies should be managed in expert centers with a multidisciplinary team including hematology, maternal-fetal medicine, and neonatology due to increased maternal and fetal risks 4, 5

Failure to screen the partner for thalassemia carrier status can result in missed diagnosis of at-risk pregnancies for Hemoglobin Bart's hydrops fetalis 2
Delayed recognition of worsening anemia during pregnancy can compromise both maternal and fetal outcomes—maintain regular CBC monitoring 1